diff --git a/docs/src/main/asciidoc/README.adoc b/docs/src/main/asciidoc/README.adoc index d143627a..5974845a 100644 --- a/docs/src/main/asciidoc/README.adoc +++ b/docs/src/main/asciidoc/README.adoc @@ -8,23 +8,25 @@ include::intro.adoc[] === Spring Cloud Config Server -* HTTP, resource-based API for external configuration (name-value pairs, or equivalent YAML content) +Spring Cloud Config Server offers the following benefits: + +* HTTP resource-based API for external configuration (name-value pairs or equivalent YAML content) * Encrypt and decrypt property values (symmetric or asymmetric) * Embeddable easily in a Spring Boot application using `@EnableConfigServer` === Spring Cloud Config Client -Specifically for Spring applications: +Specifically for Spring applications, Spring Cloud Config lets you: -* Bind to the Config Server and initialize Spring `Environment` with remote property sources -* Encrypt and decrypt property values (symmetric or asymmetric) -* `@RefreshScope` for Spring `@Beans` that want to be re-initialized when configuration changes -* Management endpoints: -** `/env` for updating `Environment` and rebinding `@ConfigurationProperties` and log levels -** `/refresh` for refreshing the `@RefreshScope` beans -** `/restart` for restarting the Spring context (disabled by default) -** `/pause` and `/resume` for calling the `Lifecycle` methods (`stop()` and `start()` on the `ApplicationContext`) -* Bootstrap application context: a parent context for the main application that can be trained to do anything (by default it binds to the Config Server, and decrypts property values) +* Bind to the Config Server and initialize Spring `Environment` with remote property sources. +* Encrypt and decrypt property values (symmetric or asymmetric). +* `@RefreshScope` for Spring `@Beans` that want to be re-initialized when configuration changes. +* Use management endpoints: +** `/env` for updating `Environment` and rebinding `@ConfigurationProperties` and log levels. +** `/refresh` for refreshing the `@RefreshScope` beans. +** `/restart` for restarting the Spring context (disabled by default). +** `/pause` and `/resume` for calling the `Lifecycle` methods (`stop()` and `start()` on the `ApplicationContext`). +* Bootstrap application context: a parent context for the main application that can be trained to do anything (by default, it binds to the Config Server and decrypts property values). == Quick Start @@ -32,48 +34,38 @@ include::quickstart.adoc[] === Sample Application -There is a sample application -https://github.com/spring-cloud/spring-cloud-config/tree/master/spring-cloud-config-sample[here]. It -is a Spring Boot application so you can run it using the usual -mechanisms (for instance "mvn spring-boot:run"). When it runs it will -look for the config server on "http://localhost:8888" by default, so -you could run the server as well to see it all working together. +You can find a sample application https://github.com/spring-cloud/spring-cloud-config/tree/master/spring-cloud-config-sample[here]. +It is a Spring Boot application, so you can run it by using the usual mechanisms (for instance, `mvn spring-boot:run`). +When it runs, it looks for the config server on `http://localhost:8888` (a configurable default), so you can run the server as well to see it all working together. -The sample has a test case where the config server is also started in -the same JVM (with a different port), and the test asserts that an -environment property from the git configuration repo is present. To -change the location of the config server just set -"spring.cloud.config.uri" in "bootstrap.yml" (or via System -properties etc.). +The sample has a test case where the config server is also started in the same JVM (with a different port), and the test asserts that an +environment property from the git configuration repo is present. +To change the location of the config server, you can set `spring.cloud.config.uri` in `bootstrap.yml` (or in system properties and other places). -The test case has a `main()` method that runs the server in the same -way (watch the logs for its port), so you can run the whole system in -one process and play with it (e.g. right click on the main in your IDE -and run it). The `main()` method uses `target/config` for the working -directory of the git repository, so you can make local changes there -and see them reflected in the running app. +The test case has a `main()` method that runs the server in the same way (watch the logs for its port), so you can run the whole system in one process and play with it (for example, you can run the `main()` method in your IDE). +The `main()` method uses `target/config` for the working directory of the git repository, so you can make local changes there and see them reflected in the running app. The following example shows a session of tinkering with the test case: ---- -$ curl localhost:8080/env/foo -bar -$ vi target/config/bar.properties -.. change value of "foo", optionally commit +$ curl localhost:8080/env/sample +mytest +$ vi target/config/mytest.properties +.. change value of "sample", optionally commit $ curl localhost:8080/refresh -["foo"] -$ curl localhost:8080/env/foo -baz +["sample"] +$ curl localhost:8080/env/sample +sampleValue ---- -The refresh endpoint reports that the "foo" property changed. +The refresh endpoint reports that the "sample" property changed. == Building +include::https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/master/docs/src/main/asciidoc/building.adoc[] + === JCE -If you are getting an exception due to "Illegal key size" and you -are using Sun’s JDK, you need to install the Java Cryptography -Extension (JCE) Unlimited Strength Jurisdiction Policy Files. See -the following links for more information: +If you get an exception due to "Illegal key size" and you are using Sun’s JDK, you need to install the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files. +See the following links for more information: http://www.oracle.com/technetwork/java/javase/downloads/jce-6-download-429243.html[Java 6 JCE] @@ -81,9 +73,7 @@ http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.ht http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html[Java 8 JCE] -Extract files into JDK/jre/lib/security folder (whichever version of JRE/JDK x64/x86 you are using). - -include::https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/master/docs/src/main/asciidoc/building.adoc[] +Extract the JCE files into the `JDK/jre/lib/security` folder for whichever version of JRE/JDK x64/x86 you use. == Contributing diff --git a/docs/src/main/asciidoc/intro.adoc b/docs/src/main/asciidoc/intro.adoc index 989710cd..7509846a 100644 --- a/docs/src/main/asciidoc/intro.adoc +++ b/docs/src/main/asciidoc/intro.adoc @@ -1,3 +1,6 @@ -Spring Cloud Config provides server and client-side support for externalized configuration in a distributed system. With the Config Server you have a central place to manage external properties for applications across all environments. The concepts on both client and server map identically to the Spring `Environment` and `PropertySource` abstractions, so they fit very well with Spring applications, but can be used with any application running in any language. As an application moves through the deployment pipeline from dev to test and into production you can manage the configuration between those environments and be certain that applications have everything they need to run when they migrate. The default implementation of the server storage backend uses git so it easily supports labelled versions of configuration environments, as well as being accessible to a wide range of tooling for managing the content. It is easy to add alternative implementations and plug them in with Spring configuration. - +Spring Cloud Config provides server-side and client-side support for externalized configuration in a distributed system. With the Config Server, you have a central place to manage external properties for applications across all environments. +The concepts on both client and server map identically to the Spring `Environment` and `PropertySource` abstractions, so they fit very well with Spring applications but can be used with any application running in any language. +As an application moves through the deployment pipeline from dev to test and into production, you can manage the configuration between those environments and be certain that applications have everything they need to run when they migrate. +The default implementation of the server storage backend uses git, so it easily supports labelled versions of configuration environments as well as being accessible to a wide range of tooling for managing the content. +It is easy to add alternative implementations and plug them in with Spring configuration. diff --git a/docs/src/main/asciidoc/quickstart.adoc b/docs/src/main/asciidoc/quickstart.adoc index 404147bb..3ae09548 100644 --- a/docs/src/main/asciidoc/quickstart.adoc +++ b/docs/src/main/asciidoc/quickstart.adoc @@ -1,13 +1,15 @@ -Start the server: +This quick start walks through using both the server and the client of Spring Cloud Config Server. + +First, start the server, as follows: ---- $ cd spring-cloud-config-server $ ../mvnw spring-boot:run ---- -The server is a Spring Boot application so you can run it from your -IDE instead if you prefer (the main class is -`ConfigServerApplication`). Then try out a client: +The server is a Spring Boot application, so you can run it from your IDE if you prefer to do so (the main class is `ConfigServerApplication`). + +Next try out a client, as follows: ---- $ curl localhost:8888/foo/development @@ -17,13 +19,10 @@ $ curl localhost:8888/foo/development ]} ---- -The default strategy for locating property sources is to clone a git -repository (at `spring.cloud.config.server.git.uri`) and use it to -initialize a mini `SpringApplication`. The mini-application's -`Environment` is used to enumerate property sources and publish them -via a JSON endpoint. +The default strategy for locating property sources is to clone a git repository (at `spring.cloud.config.server.git.uri`) and use it to initialize a mini `SpringApplication`. +The mini-application's `Environment` is used to enumerate property sources and publish them at a JSON endpoint. -The HTTP service has resources in the form: +The HTTP service has resources in the following form: ---- /{application}/{profile}[/{label}] @@ -33,14 +32,9 @@ The HTTP service has resources in the form: /{label}/{application}-{profile}.properties ---- -where the "application" is injected as the `spring.config.name` in the -`SpringApplication` (i.e. what is normally "application" in a regular -Spring Boot app), "profile" is an active profile (or comma-separated -list of properties), and "label" is an optional git label (defaults to -"master".) +where `application` is injected as the `spring.config.name` in the `SpringApplication` (what is normally `application` in a regular Spring Boot app), `profile` is an active profile (or comma-separated list of properties), and `label` is an optional git label (defaults to `master`.) -Spring Cloud Config Server pulls configuration for remote clients -from a git repository (which must be provided): +Spring Cloud Config Server pulls configuration for remote clients from a git repository (which must be provided), as shown in the following example: [source,yaml] ---- @@ -54,14 +48,9 @@ spring: === Client Side Usage -To use these features in an application, just build it as a Spring -Boot application that depends on spring-cloud-config-client (e.g. see -the test cases for the config-client, or the sample app). The most -convenient way to add the dependency is via a Spring Boot starter -`org.springframework.cloud:spring-cloud-starter-config`. There is also a -parent pom and BOM (`spring-cloud-starter-parent`) for Maven users and a -Spring IO version management properties file for Gradle and Spring CLI -users. Example Maven configuration: +To use these features in an application, you can build it as a Spring Boot application that depends on spring-cloud-config-client (for an example, see the test cases for the config-client or the sample application). +The most convenient way to add the dependency is with a Spring Boot starter `org.springframework.cloud:spring-cloud-starter-config`. +There is also a parent pom and BOM (`spring-cloud-starter-parent`) for Maven users and a Spring IO version management properties file for Gradle and Spring CLI users. The following example shows a typical Maven configuration: [source,xml,indent=0] .pom.xml @@ -109,7 +98,7 @@ users. Example Maven configuration: ---- -Then you can create a standard Spring Boot application, like this simple HTTP server: +Now you can create a standard Spring Boot application, such as the following HTTP server: ---- @SpringBootApplication @@ -128,18 +117,14 @@ public class Application { } ---- -When it runs it will pick up the external configuration from the -default local config server on port 8888 if it is running. To modify -the startup behaviour you can change the location of the config server -using `bootstrap.properties` (like `application.properties` but for -the bootstrap phase of an application context), e.g. +When this HTTP server runs, it picks up the external configuration from the default local config server (if it is running) on port 8888. +To modify the startup behavior, you can change the location of the config server by using `bootstrap.properties` (similar to `application.properties` but for the bootstrap phase of an application context), as shown in the following example: ---- spring.cloud.config.uri: http://myconfigserver.com ---- -The bootstrap properties will show up in the `/env` endpoint as a -high-priority property source, e.g. +The bootstrap properties show up in the `/env` endpoint as a high-priority property source, as shown in the following example. ---- $ curl localhost:8080/env @@ -152,9 +137,6 @@ $ curl localhost:8080/env } ---- -(a property source called "configService:/" contains the property "foo" with value -"bar" and is highest priority). +A property source called ```configService:/` contains the `foo` property with a value of `bar` and is highest priority. -NOTE: the URL in the property source name is the git repository not -the config server URL. +NOTE: The URL in the property source name is the git repository, not the config server URL. diff --git a/docs/src/main/asciidoc/spring-cloud-config.adoc b/docs/src/main/asciidoc/spring-cloud-config.adoc index 5205ed86..20a0b121 100644 --- a/docs/src/main/asciidoc/spring-cloud-config.adoc +++ b/docs/src/main/asciidoc/spring-cloud-config.adoc @@ -4,6 +4,7 @@ :docslink: {githubmaster}/docs/src/main/asciidoc :toc: :nofooter: +:special-string: $$_$$ *{spring-cloud-version}* @@ -15,10 +16,9 @@ include::quickstart.adoc[] == Spring Cloud Config Server -The Server provides an HTTP, resource-based API for external -configuration (name-value pairs, or equivalent YAML content). The -server is easily embeddable in a Spring Boot application using the -`@EnableConfigServer` annotation. So this app is a config server: +Spring Cloud Config Server provides an HTTP resource-based API for external configuration (name-value pairs or equivalent YAML content). +The server is embeddable in a Spring Boot application, by using the `@EnableConfigServer` annotation. +Consequently, the following application is a config server: .ConfigServer.java [source,java] @@ -32,12 +32,9 @@ public class ConfigServer { } ---- -Like all Spring Boot apps it runs on port 8080 by default, but you -can switch it to the conventional port 8888 in various ways. The -easiest, which also sets a default configuration repository, -is by launching it with `spring.config.name=configserver` (there -is a `configserver.yml` in the Config Server jar). Another is -to use your own `application.properties`, e.g. +Like all Spring Boot applications, it runs on port 8080 by default, but you can switch it to the more conventional port 8888 in various ways. +The easiest, which also sets a default configuration repository, is by launching it with `spring.config.name=configserver` (there is a `configserver.yml` in the Config Server jar). +Another is to use your own `application.properties`, as shown in the following example: .application.properties [source,properties] @@ -46,16 +43,13 @@ server.port: 8888 spring.cloud.config.server.git.uri: file://${user.home}/config-repo ---- -where `${user.home}/config-repo` is a git repository containing -YAML and properties files. +where `${user.home}/config-repo` is a git repository containing YAML and properties files. -NOTE: in Windows you need an extra "/" in the file URL if it is -absolute with a drive prefix, e.g. `file:///${user.home}/config-repo`. +NOTE: On Windows, you need an extra "/" in the file URL if it is absolute with a drive prefix (for example,`file:///${user.home}/config-repo`). [TIP] ==== -Here's a recipe for creating the git repository in the example -above: +The following listing shows a recipe for creating the git repository in the preceding example: ---- $ cd $HOME @@ -68,41 +62,28 @@ $ git commit -m "Add application.properties" ---- ==== -WARNING: using the local filesystem for your git repository is -intended for testing only. Use a server to host your -configuration repositories in production. +WARNING: Using the local filesystem for your git repository is intended for testing only. +You should use a server to host your configuration repositories in production. -WARNING: the initial clone of your configuration repository will -be quick and efficient if you only keep text files in it. If you start -to store binary files, especially large ones, you may experience -delays on the first request for configuration and/or out of memory -errors in the server. +WARNING: The initial clone of your configuration repository can be quick and efficient if you keep only text files in it. +If you store binary files, especially large ones, you may experience delays on the first request for configuration or encounter out of memory errors in the server. === Environment Repository -Where do you want to store the configuration data for the Config -Server? The strategy that governs this behaviour is the -`EnvironmentRepository`, serving `Environment` objects. This -`Environment` is a shallow copy of the domain from the Spring -`Environment` (including `propertySources` as the main feature). The -`Environment` resources are parametrized by three variables: +Where should you store the configuration data for the Config Server? +The strategy that governs this behaviour is the `EnvironmentRepository`, serving `Environment` objects. +This `Environment` is a shallow copy of the domain from the Spring `Environment` (including `propertySources` as the main feature). +The `Environment` resources are parametrized by three variables: -* `{application}` maps to "spring.application.name" on the client side; +* `{application}`, which maps to `spring.application.name` on the client side. +* `{profile}`, which maps to `spring.profiles.active` on the client (comma-separated list). +* `{label}`, which is a server side feature labelling a "versioned" set of config files. -* `{profile}` maps to "spring.profiles.active" on the client (comma separated list); and +Repository implementations generally behave like a Spring Boot application, loading configuration files from a `spring.config.name` equal to the `{application}` parameter, and `spring.profiles.active` equal to the `{profiles}` parameter. +Precedence rules for profiles are also the same as in a regular Spring Boot application: Active profiles take precedence over defaults, and, if there are multiple profiles, the last one wins (similar to adding entries to a `Map`). -* `{label}` which is a server side feature labelling a "versioned" set of config files. - -Repository implementations generally behave just like a Spring Boot -application loading configuration files from a "spring.config.name" -equal to the `{application}` parameter, and "spring.profiles.active" -equal to the `{profiles}` parameter. Precedence rules for profiles are -also the same as in a regular Boot application: active profiles take -precedence over defaults, and if there are multiple profiles the last -one wins (like adding entries to a `Map`). - -Example: a client application has this bootstrap configuration: +The following sample client application has this bootstrap configuration: .bootstrap.yml [source,yaml] @@ -114,57 +95,36 @@ spring: active: dev,mysql ---- -(as usual with a Spring Boot application, these properties could also -be set as environment variables or command line arguments). +(As usual with a Spring Boot application, these properties could also be set by environment variables or command line arguments). -If the repository is file-based, the server will create an -`Environment` from `application.yml` (shared between all clients), and -`foo.yml` (with `foo.yml` taking precedence). If the YAML files have -documents inside them that point to Spring profiles, those are applied -with higher precedence (in order of the profiles listed), and if -there are profile-specific YAML (or properties) files these are also -applied with higher precedence than the defaults. Higher precedence -translates to a `PropertySource` listed earlier in the -`Environment`. (These are the same rules as apply in a standalone -Spring Boot application.) +If the repository is file-based, the server creates an +`Environment` from `application.yml` (shared between all clients) and +`foo.yml` (with `foo.yml` taking precedence). +If the YAML files have documents inside them that point to Spring profiles, those are applied with higher precedence (in order of the profiles listed). +If there are profile-specific YAML (or properties) files, these are also applied with higher precedence than the defaults. +Higher precedence translates to a `PropertySource` listed earlier in the `Environment`. +(These same rules apply in a standalone Spring Boot application.) ==== Git Backend -The default implementation of `EnvironmentRepository` uses a Git -backend, which is very convenient for managing upgrades and physical -environments, and also for auditing changes. To change the location of -the repository you can set the "spring.cloud.config.server.git.uri" -configuration property in the Config Server (e.g. in -`application.yml`). If you set it with a `file:` prefix it should work -from a local repository so you can get started quickly and easily -without a server, but in that case the server operates directly on the -local repository without cloning it (it doesn't matter if it's not -bare because the Config Server never makes changes to the "remote" -repository). To scale the Config Server up and make it highly -available, you would need to have all instances of the server pointing -to the same repository, so only a shared file system would work. Even -in that case it is better to use the `ssh:` protocol for a shared -filesystem repository, so that the server can clone it and use a local -working copy as a cache. +The default implementation of `EnvironmentRepository` uses a Git backend, which is very convenient for managing upgrades and physical +environments and for auditing changes. +To change the location of the repository, you can set the `spring.cloud.config.server.git.uri` configuration property in the Config Server (for example in `application.yml`). +If you set it with a `file:` prefix, it should work from a local repository so that you can get started quickly and easily without a server. However, in that case, the server operates directly on the local repository without cloning it (it does not matter if it is not bare because the Config Server never makes changes to the "remote" repository). +To scale the Config Server up and make it highly available, you need to have all instances of the server pointing to the same repository, so only a shared file system would work. +Even in that case, it is better to use the `ssh:` protocol for a shared filesystem repository, so that the server can clone it and use a local working copy as a cache. -This repository implementation maps the `{label}` parameter of the -HTTP resource to a git label (commit id, branch name or tag). If the -git branch or tag name contains a slash ("/") then the label in the -HTTP URL should be specified with the special string "($$_$$)" instead (to -avoid ambiguity with other URL paths). For example, if the label is -`foo/bar`, replacing the slash would result in a label that looks like -`foo($$_$$)bar`. The inclusion of the special string "($$_$$)" can also be -applied to the `{application}` parameter. Be careful with the brackets -in the URL if you are using a command line client like curl (e.g. -escape them from the shell with quotes ''). +This repository implementation maps the `{label}` parameter of the HTTP resource to a git label (commit id, branch name, or tag). +If the git branch or tag name contains a slash (`/`), then the label in the HTTP URL should instead be specified with the special string `{special-string}` (to avoid ambiguity with other URL paths). +For example, if the label is `foo/bar`, replacing the slash would result in the following label: `foo({special-string})bar`. +The inclusion of the special string `({special-string})` can also be applied to the `{application}` parameter. +If you use a command-line client such as curl, be careful with the brackets in the URL -- you should +escape them from the shell with single quotes (''). ===== Placeholders in Git URI -Spring Cloud Config Server supports a git repository URL with -placeholders for the `{application}` and `{profile}` (and `{label}` if -you need it, but remember that the label is applied as a git label -anyway). So you can easily support a "one repo per application" policy -using (for example): +Spring Cloud Config Server supports a git repository URL with placeholders for the `{application}` and `{profile}` (and `{label}` if you need it, but remember that the label is applied as a git label anyway). +So you can support a "`one repository per application`" policy by using a structure similar to the following: [source,yaml] ---- @@ -176,12 +136,11 @@ spring: uri: https://github.com/myorg/{application} ---- -or a "one repo per profile" policy using a similar pattern but with +You can also support a "`one repository per profile`" policy by using a similar pattern but with `{profile}`. -Additionally, using the special string "($$_$$)" within your -`{application}` parameters can enable support for multiple -organizations (for example): +Additionally, using the special string "({special-string})" within your `{application}` parameters can enable support for multiple +organizations, as shown in the following example: [source,yaml] ---- @@ -193,16 +152,13 @@ spring: uri: https://github.com/{application} ---- -where `{application}` is provided at request time in the format -"organization($$_$$)application". +where `{application}` is provided at request time in the following format: `organization({special-string})application`. ===== Pattern Matching and Multiple Repositories -There is also support for more complex requirements with pattern -matching on the application and profile name. The pattern format is a -comma-separated list of `{application}/{profile}` names with wildcards -(where a pattern beginning with a wildcard may need to be -quoted). Example: +Spring Cloud Config also includes support for more complex requirements with pattern +matching on the application and profile name. +The pattern format is a comma-separated list of `{application}/{profile}` names with wildcards (note that a pattern beginning with a wildcard may need to be quoted), as shown in the following example: [source,yaml] ---- @@ -222,24 +178,14 @@ spring: uri: file:/home/configsvc/config-repo ---- -If `{application}/{profile}` does not match any of the patterns, it -will use the default uri defined under -"spring.cloud.config.server.git.uri". In the above example, for the -"simple" repository, the pattern is `simple/\*` (i.e. it only matches -one application named "simple" in all profiles). The "local" -repository matches all application names beginning with "local" in all -profiles (the `/*` suffix is added automatically to any pattern that -doesn't have a profile matcher). +If `{application}/{profile}` does not match any of the patterns, it uses the default URI defined under `spring.cloud.config.server.git.uri`. +In the above example, for the "`simple`" repository, the pattern is `simple/\*` (it only matches one application named `simple` in all profiles). The "`local`" repository matches all application names beginning with `local` in all profiles (the `/*` suffix is added automatically to any pattern that does not have a profile matcher). -NOTE: the "one-liner" short cut used in the "simple" example above can -only be used if the only property to be set is the URI. If you need to -set anything else (credentials, pattern, etc.) you need to use the full -form. +NOTE: The "`one-liner`" short cut used in the "`simple`" example can be used only if the only property to be set is the URI. +If you need to set anything else (credentials, pattern, and so on) you need to use the full form. -The `pattern` property in the repo is actually an array, so you can -use a YAML array (or `[0]`, `[1]`, etc. suffixes in properties files) -to bind to multiple patterns. You may need to do this if you are going -to run apps with multiple profiles. Example: +The `pattern` property in the repo is actually an array, so you can use a YAML array (or `[0]`, `[1]`, etc. suffixes in properties files) to bind to multiple patterns. +You may need to do so if you are going to run apps with multiple profiles, as shown in the following example: [source,yaml] ---- @@ -262,16 +208,11 @@ spring: uri: https://github.com/staging/config-repo ---- -NOTE: Spring Cloud will guess that a pattern containing a profile that -doesn't end in `\*` implies that you actually want to match a list of -profiles starting with this pattern (so `*/staging` is a shortcut for -`["\*/staging", "*/staging,*"]`). This is common where you need to run -apps in the "development" profile locally but also the "cloud" profile -remotely, for instance. +NOTE: Spring Cloud guesses that a pattern containing a profile that does not end in `\*` implies that you actually want to match a list of profiles starting with this pattern (so `*/staging` is a shortcut for `["\*/staging", "*/staging,*"]`, and so on). +This is common where, for instance, you need to run applications in the "`development`" profile locally but also the "`cloud`" profile remotely. -Every repository can also optionally store config files in -sub-directories, and patterns to search for those directories can be -specified as `searchPaths`. For example at the top level: +Every repository can also optionally store config files in sub-directories, and patterns to search for those directories can be specified as `searchPaths`. +The following example shows a config file at the top level: [source,yaml] ---- @@ -284,13 +225,11 @@ spring: searchPaths: foo,bar* ---- -In this example the server searches for config files in the top level -and in the "foo/" sub-directory and also any sub-directory whose name -begins with "bar". +In the preceding example, the server searches for config files in the top level and in the `foo/` sub-directory and also any sub-directory whose name begins with `bar`. -By default the server clones remote repositories when configuration -is first requested. The server can be configured to clone the repositories -at startup. For example at the top level: +By default, the server clones remote repositories when configuration +is first requested. +The server can be configured to clone the repositories at startup, as shown in the following top-level example: [source,yaml] ---- @@ -315,23 +254,16 @@ spring: ---- -In this example the server clones team-a's config-repo on startup before it -accepts any requests. All other repositories will not be cloned until -configuration from the repository is requested. +In the preceding example, the server clones team-a's config-repo on startup, before it +accepts any requests. +All other repositories are not cloned until configuration from the repository is requested. -NOTE: Setting a repository to be cloned when the Config Server starts up can -help to identify a misconfigured configuration source (e.g., an invalid -repository URI) quickly, while the Config Server is starting up. With -`cloneOnStart` not enabled for a configuration source, the Config Server may -start successfully with a misconfigured or invalid configuration source and -not detect an error until an application requests configuration from that -configuration source. +NOTE: Setting a repository to be cloned when the Config Server starts up can help to identify a misconfigured configuration source (such as an invalid repository URI) quickly, while the Config Server is starting up. +With `cloneOnStart` not enabled for a configuration source, the Config Server may start successfully with a misconfigured or invalid configuration source and not detect an error until an application requests configuration from that configuration source. ===== Authentication -To use HTTP basic authentication on the remote repository add the -"username" and "password" properties separately (not in the URL), -e.g. +To use HTTP basic authentication on the remote repository, add the `username` and `password` properties separately (not in the URL), as shown in the following example: [source,yaml] ---- @@ -345,47 +277,39 @@ spring: password: strongpassword ---- -If you don't use HTTPS and user credentials, SSH should also work out -of the box when you store keys in the default directories (`~/.ssh`) -and the uri points to an SSH location, -e.g. "git@github.com:configuration/cloud-configuration". It is important that an entry for the Git server be present in the `~/.ssh/known_hosts` file and that it is in `ssh-rsa` format. Other formats (like `ecdsa-sha2-nistp256`) are not supported. To avoid surprises, you should ensure that only one entry is present in the `known_hosts` file for the Git server and that it is matching with the URL you provided to the config server. If you used a hostname in the URL, you want to have exactly that in the `known_hosts` file, not the IP. -The repository is accessed using JGit, so any documentation you find on -that should be applicable. HTTPS proxy settings can be set in -`~/.git/config` or in the same way as for any other JVM process via +If you do not use HTTPS and user credentials, SSH should also work out of the box when you store keys in the default directories (`~/.ssh`) and the URI points to an SSH location, such as `git@github.com:configuration/cloud-configuration`. +It is important that an entry for the Git server be present in the `~/.ssh/known_hosts` file and that it is in `ssh-rsa` format. +Other formats (such as `ecdsa-sha2-nistp256`) are not supported. +To avoid surprises, you should ensure that only one entry is present in the `known_hosts` file for the Git server and that it matches the URL you provided to the config server. +If you use a hostname in the URL, you want to have exactly that (not the IP) in the `known_hosts` file. +The repository is accessed by using JGit, so any documentation you find on that should be applicable. +HTTPS proxy settings can be set in `~/.git/config` or (in the same way as for any other JVM process) with system properties (`-Dhttps.proxyHost` and `-Dhttps.proxyPort`). -TIP: If you don't know where your `~/.git` directory is use `git config ---global` to manipulate the settings (e.g. `git config --global -http.sslVerify false`). +TIP: If you do not know where your `~/.git` directory is, use `git config --global` to manipulate the settings (for example, `git config --global http.sslVerify false`). ===== Authentication with AWS CodeCommit -http://docs.aws.amazon.com/codecommit/latest/userguide/welcome.html[AWS CodeCommit] authentication can also be -done. AWS CodeCommit uses an authentication helper when using Git from the command line. This helper is not -used with the JGit library, so a JGit CredentialProvider for AWS CodeCommit will be created if the Git -URI matches the AWS CodeCommit pattern. AWS CodeCommit URIs always look like -https://git-codecommit.${AWS_REGION}.amazonaws.com/${repopath}. +Spring Cloud Config Server also supports http://docs.aws.amazon.com/codecommit/latest/userguide/welcome.html[AWS CodeCommit] authentication. +AWS CodeCommit uses an authentication helper when using Git from the command line. +This helper is not used with the JGit library, so a JGit CredentialProvider for AWS CodeCommit is created if the Git URI matches the AWS CodeCommit pattern. +AWS CodeCommit URIs follow this pattern://git-codecommit.${AWS_REGION}.amazonaws.com/${repopath}. -If you provide a username and password with an AWS CodeCommit URI, then these must be -the http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSGettingStartedGuide/AWSCredentials.html[AWS accessKeyId and secretAccessKey] -to be used to access the repository. If you do not specify a username and password, -then the accessKeyId and secretAccessKey will be retrieved using the -http://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/credentials.html[AWS Default Credential Provider Chain]. +If you provide a username and password with an AWS CodeCommit URI, they must be the http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSGettingStartedGuide/AWSCredentials.html[AWS accessKeyId and secretAccessKey] that provide access to the repository. +If you do not specify a username and password, the accessKeyId and secretAccessKey are retrieved by using the http://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/credentials.html[AWS Default Credential Provider Chain]. -If your Git URI matches the CodeCommit URI pattern (above) then you must provide -valid AWS credentials in the username and password, or in one of the locations supported -by the default credential provider chain. AWS EC2 instances may use -http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html[IAM Roles for EC2 Instances]. +If your Git URI matches the CodeCommit URI pattern (shown earlier), you must provide valid AWS credentials in the username and password or in one of the locations supported by the default credential provider chain. +AWS EC2 instances may use http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html[IAM Roles for EC2 Instances]. -Note: The aws-java-sdk-core jar is an optional dependency. If the aws-java-sdk-core jar is not on your -classpath, then the AWS Code Commit credential provider will not be created regardless of the git server URI. +NOTE: The `aws-java-sdk-core` jar is an optional dependency. +If the `aws-java-sdk-core` jar is not on your classpath, the AWS Code Commit credential provider is not created, regardless of the git server URI. ===== Git SSH configuration using properties -By default, the JGit library used by Spring Cloud Config Server uses SSH configuration files such as `~/.ssh/known_hosts` and `/etc/ssh/ssh_config` when connecting to Git repositories using an SSH URI. -In cloud environments such as Cloud Foundry, the local filesystem may be ephemeral or not easily accessible. For cases such as these, SSH configuration can be set using -Java properties. In order to activate property based SSH configuration, the property `spring.cloud.config.server.git.ignoreLocalSshSettings` must be set to `true`. -Example: +By default, the JGit library used by Spring Cloud Config Server uses SSH configuration files such as `~/.ssh/known_hosts` and `/etc/ssh/ssh_config` when connecting to Git repositories by using an SSH URI. +In cloud environments such as Cloud Foundry, the local filesystem may be ephemeral or not easily accessible. +For those cases, SSH configuration can be set by using Java properties. +In order to activate property-based SSH configuration, the `spring.cloud.config.server.git.ignoreLocalSshSettings` property must be set to `true`, as shown in the following example: [source,yaml] ---- @@ -429,38 +353,38 @@ Example: ---- -.SSH Configuration properties +The following table describes the SSH configuration properties. + +.SSH Configuration Properties |=== |Property Name |Remarks |*ignoreLocalSshSettings* -|If true, use property based SSH config instead of file based. Must be set at as `spring.cloud.config.server.git.ignoreLocalSshSettings`, *not* inside a repository definition. +|If `true`, use property-based instead of file-based SSH config. Must be set at as `spring.cloud.config.server.git.ignoreLocalSshSettings`, *not* inside a repository definition. |*privateKey* -|Valid SSH private key. Must be set if `ignoreLocalSshSettings` is true and Git URI is SSH format +|Valid SSH private key. Must be set if `ignoreLocalSshSettings` is true and Git URI is SSH format. |*hostKey* -|Valid SSH host key. Must be set if `hostKeyAlgorithm` is also set +|Valid SSH host key. Must be set if `hostKeyAlgorithm` is also set. |*hostKeyAlgorithm* -|One of `ssh-dss, ssh-rsa, ecdsa-sha2-nistp256, ecdsa-sha2-nistp384 ,ecdsa-sha2-nistp521`. Must be set if `hostKey` is also set +|One of `ssh-dss, ssh-rsa, ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, or ecdsa-sha2-nistp521`. Must be set if `hostKey` is also set. |*strictHostKeyChecking* -|`true` or `false`. If false, ignore errors with host key +|`true` or `false`. If false, ignore errors with host key. |*knownHostsFile* -|Location of custom .known_hosts file +|Location of custom `.known_hosts` file. |*preferredAuthentications* -|Override server authentication method order. This should allow evade login prompts if server has keyboard-interactive authentication before `publickey` method. +|Override server authentication method order. This should allow for evading login prompts if server has keyboard-interactive authentication before the `publickey` method. |=== - ===== Placeholders in Git Search Paths -Spring Cloud Config Server also supports a search path with -placeholders for the `{application}` and `{profile}` (and `{label}` if -you need it). Example: +Spring Cloud Config Server also supports a search path with placeholders for the `{application}` and `{profile}` (and `{label}` if +you need it), as shown in the following example: [source,yaml] ---- @@ -473,21 +397,15 @@ spring: searchPaths: '{application}' ---- -searches the repository for files in the same name as the directory -(as well as the top level). Wildcards are also valid in a search -path with placeholders (any matching directory is included in the -search). +The preceding listing causes a search of the repository for files in the same name as the directory (as well as the top level). +Wildcards are also valid in a search path with placeholders (any matching directory is included in the search). ===== Force pull in Git Repositories -As mentioned before Spring Cloud Config Server makes a clone of the -remote git repository and if somehow the local copy gets dirty (e.g. -folder content changes by OS process) so Spring Cloud Config Server -cannot update the local copy from remote repository. +As mentioned earlier, Spring Cloud Config Server makes a clone of the remote git repository in case the local copy gets dirty (for example, +folder content changes by an OS process) such that Spring Cloud Config Server cannot update the local copy from remote repository. -To solve this there is a `force-pull` property that will make Spring Cloud -Config Server force pull from remote repository if the local copy is dirty. -Example: +To solve this issue, there is a `force-pull` property that makes Spring Cloud Config Server force pull from the remote repository if the local copy is dirty, as shown in the following example: [source,yaml] ---- @@ -501,8 +419,7 @@ spring: ---- -If you have a multiple repositories configuration you can configure the -`force-pull` property per repository. Example: +If you have a multiple-repositories configuration, you can configure the `force-pull` property per repository, as shown in the following example: [source,yaml] ---- @@ -558,74 +475,54 @@ NOTE: The default value for `deleteUntrackedBranches` property is `false`. ==== Version Control Backend Filesystem Use -WARNING: With VCS based backends (git, svn) files are checked out or cloned to the local filesystem. By default they are put in the system temporary directory with a prefix of `config-repo-`. On linux, for example it could be `/tmp/config-repo-`. Some operating systems http://serverfault.com/questions/377348/when-does-tmp-get-cleared/377349#377349[routinely clean out] temporary directories. This can lead to unexpected behaviour such as missing properties. To avoid this problem, change the directory Config Server uses, by setting `spring.cloud.config.server.git.basedir` or `spring.cloud.config.server.svn.basedir` to a directory that does not reside in the system temp structure. +WARNING: With VCS-based backends (git, svn), files are checked out or cloned to the local filesystem. +By default, they are put in the system temporary directory with a prefix of `config-repo-`. +On linux, for example, it could be `/tmp/config-repo-`. +Some operating systems http://serverfault.com/questions/377348/when-does-tmp-get-cleared/377349#377349[routinely clean out] temporary directories. +This can lead to unexpected behavior, such as missing properties. +To avoid this problem, change the directory that Config Server uses by setting `spring.cloud.config.server.git.basedir` or `spring.cloud.config.server.svn.basedir` to a directory that does not reside in the system temp structure. ==== File System Backend -There is also a "native" profile in the Config Server that doesn't use -Git, but just loads the config files from the local classpath or file -system (any static URL you want to point to with -"spring.cloud.config.server.native.searchLocations"). To use the -native profile just launch the Config Server with -"spring.profiles.active=native". +There is also a "`native`" profile in the Config Server that does not use Git but loads the config files from the local classpath or file system (any static URL you want to point to with `spring.cloud.config.server.native.searchLocations`). +To use the native profile, launch the Config Server with `spring.profiles.active=native`. -NOTE: Remember to use the `file:` prefix for file resources (the -default without a prefix is usually the classpath). Just as with any -Spring Boot configuration you can embed `${}`-style environment -placeholders, but remember that absolute paths in Windows require an -extra "/", e.g. `file:///${user.home}/config-repo` +NOTE: Remember to use the `file:` prefix for file resources (the default without a prefix is usually the classpath). +As with any Spring Boot configuration, you can embed `${}`-style environment placeholders, but remember that absolute paths in Windows require an extra `/` (for example, `file:///${user.home}/config-repo`). -WARNING: The default value of the `searchLocations` is identical to a -local Spring Boot application (so `[classpath:/, classpath:/config, -file:./, file:./config]`). This does not expose the -`application.properties` from the server to all clients because any -property sources present in the server are removed before being sent -to the client. +WARNING: The default value of the `searchLocations` is identical to a local Spring Boot application (that is, `[classpath:/, classpath:/config, +file:./, file:./config]`). +This does not expose the `application.properties` from the server to all clients, because any property sources present in the server are removed before being sent to the client. -TIP: A filesystem backend is great for getting started quickly and -for testing. To use it in production you need to be sure that the -file system is reliable, and shared across all instances of the -Config Server. +TIP: A filesystem backend is great for getting started quickly and for testing. +To use it in production, you need to be sure that the file system is reliable and shared across all instances of the Config Server. -The search locations can contain placeholders for `{application}`, -`{profile}` and `{label}`. In this way you can segregate the -directories in the path, and choose a strategy that makes sense for -you (e.g. sub-directory per application, or sub-directory per -profile). +The search locations can contain placeholders for `{application}`, `{profile}`, and `{label}`. +In this way, you can segregate the directories in the path and choose a strategy that makes sense for you (such as subdirectory per application or subdirectory per profile). -If you don't use placeholders in the search locations, this repository -also appends the `{label}` parameter of the HTTP resource to a suffix -on the search path, so properties files are loaded from each search -location *and* a subdirectory with the same name as the label (the -labelled properties take precedence in the Spring Environment). Thus -the default behaviour with no placeholders is the same as adding a -search location ending with `/{label}/`. For example `file:/tmp/config` -is the same as `file:/tmp/config,file:/tmp/config/{label}`. This behavior can be -disabled by setting `spring.cloud.config.server.native.addLabelLocations=false`. +If you do not use placeholders in the search locations, this repository also appends the `{label}` parameter of the HTTP resource to a suffix on the search path, so properties files are loaded from each search location *and* a subdirectory with the same name as the label (the labelled properties take precedence in the Spring Environment). +Thus, the default behaviour with no placeholders is the same as adding a search location ending with `/{label}/`. +For example, `file:/tmp/config` is the same as `file:/tmp/config,file:/tmp/config/{label}`. +This behavior can be disabled by setting `spring.cloud.config.server.native.addLabelLocations=false`. ==== Vault Backend Spring Cloud Config Server also supports https://www.vaultproject.io[Vault] as a backend. + **** -Vault is a tool for securely accessing secrets. A secret is anything -that you want to tightly control access to, such as API keys, passwords, -certificates, and more. Vault provides a unified interface to any secret, -while providing tight access control and recording a detailed audit log. +Vault is a tool for securely accessing secrets. +A secret is anything that to which you want to tightly control access, such as API keys, passwords, certificates, and other sensitive information. Vault provides a unified interface to any secret while providing tight access control and recording a detailed audit log. **** -For more information on Vault see the https://www.vaultproject.io/intro/index.html[Vault quickstart guide]. +For more information on Vault, see the https://www.vaultproject.io/intro/index.html[Vault quick start guide]. -To enable the config server to use a Vault backend you can run your config server -with the `vault` profile. For example in your config server's `application.properties` -you can add `spring.profiles.active=vault`. - -By default the config server will assume your Vault server is running at -`http://127.0.0.1:8200`. It also will assume that the name of backend -is `secret` and the key is `application`. All of these defaults can be -configured in your config server's `application.properties`. Below is a -table of configurable Vault properties. All properties are prefixed with -`spring.cloud.config.server.vault`. +To enable the config server to use a Vault backend, you can run your config server with the `vault` profile. +For example, in your config server's `application.properties`, you can add `spring.profiles.active=vault`. +By default, the config server assumes that your Vault server runs at `http://127.0.0.1:8200`. +It also assumes that the name of backend is `secret` and the key is `application`. +All of these defaults can be configured in your config server's `application.properties`. +The following table describes configurable Vault properties: |=== |Name |Default Value @@ -650,13 +547,15 @@ table of configurable Vault properties. All properties are prefixed with |=== -All configurable properties can be found in -`org.springframework.cloud.config.server.environment.VaultEnvironmentRepository`. +IMPORTANT: All of the properties in the preceding table must be prefixed with `spring.cloud.config.server.vault`. -With your config server running you can make HTTP requests to the server to retrieve -values from the Vault backend. To do this you will need a token for your Vault server. +All configurable properties can be found in `org.springframework.cloud.config.server.environment.VaultEnvironmentRepository`. -First place some data in you Vault. For example +With your config server running, you can make HTTP requests to the server to retrieve +values from the Vault backend. +To do so, you need a token for your Vault server. + +First, place some data in you Vault, as shown in the following example: [source,sh] ---- @@ -664,11 +563,11 @@ $ vault write secret/application foo=bar baz=bam $ vault write secret/myapp foo=myappsbar ---- -Now make the HTTP request to your config server to retrieve the values. +Second, make an HTTP request to your config server to retrieve the values, as shown in the following example: `$ curl -X "GET" "http://localhost:8888/myapp/default" -H "X-Config-Token: yourtoken"` -You should see a response similar to this after making the above request. +You should see a response similar to the following: [source,json] ---- @@ -700,8 +599,8 @@ You should see a response similar to this after making the above request. ===== Multiple Properties Sources -When using Vault you can provide your applications with multiple properties sources. -For example, assume you have written data to the following paths in Vault. +When using Vault, you can provide your applications with multiple properties sources. +For example, assume you have written data to the following paths in Vault: [source,sh] ---- @@ -711,77 +610,56 @@ secret/application,dev secret/application ---- -Properties written to `secret/application` are available to -<<_vault_server,all applications using the Config Server>>. An -application with the name `myApp` would have any properties -written to `secret/myApp` and `secret/application` available to it. -When `myApp` has the `dev` profile enabled then properties written to -all of the above paths would be available to it, with properties in -the first path in the list taking priority over the others. +Properties written to `secret/application` are available to <<_vault_server,all applications using the Config Server>>. +An application with the name, `myApp`, would have any properties written to `secret/myApp` and `secret/application` available to it. +When `myApp` has the `dev` profile enabled, properties written to all of the above paths would be available to it, with properties in the first path in the list taking priority over the others. ==== Sharing Configuration With All Applications +Sharing configuration between all applications varies according to which approach you take, as described in the following topics: + +* <> +* <> + +[[spring-cloud-config-server-file-based-repositories]] ===== File Based Repositories -With file-based (i.e. git, svn and native) repositories, resources -with file names in `application*` are shared between all client -applications (so `application.properties`, `application.yml`, -`application-*.properties` etc.). You can use resources with these -file names to configure global defaults and have them overridden by -application-specific files as necessary. +With file-based (git, svn, and native) repositories, resources with file names in `application*` (`application.properties`, `application.yml`, `application-*.properties`, and so on) are shared between all client applications. +You can use resources with these file names to configure global defaults and have them be overridden by application-specific files as necessary. -The #_property_overrides[property overrides] feature can also be used -for setting global defaults, and with placeholders applications are +The #_property_overrides[property overrides] feature can also be used for setting global defaults, with placeholders applications allowed to override them locally. -TIP: With the "native" profile (local file system backend) it is -recommended that you use an explicit search location that isn't part -of the server's own configuration. Otherwise the `application*` -resources in the default search locations are removed because they are -part of the server. +TIP: With the "`native`" profile (a local file system backend) , you should use an explicit search location that is not part of the server's own configuration. +Otherwise, the `application*` resources in the default search locations get removed because they are part of the server. +[[spring-cloud-config-server-vault-server]] ===== Vault Server -When using Vault as a backend you can share configuration with -all applications by placing configuration in -`secret/application`. For example, if you run this Vault command +When using Vault as a backend, you can share configuration with all applications by placing configuration in `secret/application`. +For example, if you run the following Vault command, all applications using the config server will have the properties `foo` and `baz` available to them: [source,sh] ---- $ vault write secret/application foo=bar baz=bam ---- -All applications using the config server will have the properties -`foo` and `baz` available to them. - ==== JDBC Backend -Spring Cloud Config Server supports JDBC (relation database) as a -backend for configuration properties. You can enable this feature by -adding `spring-jdbc` to the classpath, and using the "jdbc" profile, -or by adding a bean of type `JdbcEnvironmentRepository`. Spring Boot -will configure a data source if you include the right dependencies on -the classpath (see the user guide for more details on that). +Spring Cloud Config Server supports JDBC (relational database) as a backend for configuration properties. +You can enable this feature by adding `spring-jdbc` to the classpath and using the `jdbc` profile or by adding a bean of type `JdbcEnvironmentRepository`. +If you include the right dependencies on the classpath (see the user guide for more details on that), Spring Boot configures a data source. +// TODO Which user guide? When we know that, we should add a link to it. -The database needs to have a table called "PROPERTIES" with columns -"APPLICATION", "PROFILE", "LABEL" (with the usual `Environment` -meaning), plus "KEY" and "VALUE" for the key and value pairs in -`Properties` style. All fields are of type String in Java, so you can -make them `VARCHAR` of whatever length you need. Property values -behave in the same way as they would if they came from Spring Boot -properties files named `{application}-{profile}.properties`, including -all the encryption and decryption, which will be applied as -post-processing steps (i.e. not in the repository implementation -directly). +The database needs to have a table called `PROPERTIES` with columns called `APPLICATION`, `PROFILE`, and `LABEL` (with the usual `Environment` meaning), plus `KEY` and `VALUE` for the key and value pairs in `Properties` style. +All fields are of type String in Java, so you can make them `VARCHAR` of whatever length you need. +Property values behave in the same way as they would if they came from Spring Boot properties files named `{application}-{profile}.properties`, including all the encryption and decryption, which will be applied as post-processing steps (that is, not in the repository implementation directly). ==== Composite Environment Repositories -In some scenarios you may wish to pull configuration data from multiple -environment repositories. To do this you can just enable -multiple profiles in your config server's application properties or YAML file. -If, for example, you want to pull configuration data from a Git repository -as well as a SVN repository you would set the following properties for your -configuration server. +In some scenarios, you may wish to pull configuration data from multiple environment repositories. +To do so, you can enable multiple profiles in your config server's application properties or YAML file. +If, for example, you want to pull configuration data from a Git repository as well as an SVN repository, you can set the following properties for your configuration server: [source,yaml] ---- @@ -799,38 +677,28 @@ spring: order: 1 ---- -In addition to each repo specifying a URI, you can also specify an `order` property. -The `order` property allows you to specify the priority order for all your repositories. -The lower the numerical value of the `order` property the higher priority it will have. -The priority order of a repository will help resolve any potential conflicts between -repositories that contain values for the same properties. +In addition to each repository specifying a URI, you can also specify an `order` property. +The `order` property lets you specify the priority order for all your repositories. +The lower the numerical value of the `order` property, the higher priority it has. +The priority order of a repository helps resolve any potential conflicts between repositories that contain values for the same properties. -NOTE: Any type of failure when retrieving values from an environment repositoy -will result in a failure for the entire composite environment. +NOTE: Any type of failure when retrieving values from an environment repository results in a failure for the entire composite environment. -NOTE: When using a composite environment it is important that all repos contain -the same label(s). If you have an environment similar to the one above and you request -configuration data with the label `master` but the SVN -repo does not contain a branch called `master` the entire request will fail. +NOTE: When using a composite environment, it is important that all repositories contain the same labels. +If you have an environment similar to the one in the preceding example and you request configuration data with the `master` label but the SVN repository does not contain a branch called `master`, the entire request fails. ===== Custom Composite Environment Repositories -It is also possible to provide your own `EnvironmentRepository` bean -to be included as part of a composite environment in addition to -using one of the environment repositories from Spring Cloud. To do this your bean -must implement the `EnvironmentRepository` interface. If you would like to control -the priority of you custom `EnvironmentRepository` within the composite -environment you should also implement the `Ordered` interface and override the -`getOrdered` method. If you do not implement the `Ordered` interface then your -`EnvironmentRepository` will be given the lowest priority. +In addition to using one of the environment repositories from Spring Cloud, you can also provide your own `EnvironmentRepository` bean to be included as part of a composite environment. +To do so, your bean must implement the `EnvironmentRepository` interface. +If you want to control the priority of your custom `EnvironmentRepository` within the composite environment, you should also implement the `Ordered` interface and override the `getOrdered` method. +If you do not implement the `Ordered` interface, your `EnvironmentRepository` is given the lowest priority. ==== Property Overrides -The Config Server has an "overrides" feature that allows the operator -to provide configuration properties to all applications that cannot be -accidentally changed by the application using the normal Spring Boot -hooks. To declare overrides just add a map of name-value pairs to -`spring.cloud.config.server.overrides`. For example +The Config Server has an "`overrides`" feature that lets the operator provide configuration properties to all applications. +The overridden properties cannot be accidentally changed by the application with the normal Spring Boot hooks. +To declare overrides, add a map of name-value pairs to `spring.cloud.config.server.overrides`, as shown in the following example: [source,yaml] ---- @@ -842,34 +710,26 @@ spring: foo: bar ---- -will cause all applications that are config clients to read `foo=bar` -independent of their own configuration. (Of course an application can -use the data in the Config Server in any way it likes, so overrides -are not enforceable, but they do provide useful default behaviour if -they are Spring Cloud Config clients.) +The preceding examples causes all applications that are config clients to read `foo=bar`, independent of their own configuration. -TIP: Normal, Spring environment placeholders with "${}" can be escaped -(and resolved on the client) by using backslash ("\") to escape the -"$" or the "{", e.g. `\${app.foo:bar}` resolves to "bar" unless the -app provides its own "app.foo". Note that in YAML you don't need to -escape the backslash itself, but in properties files you do, when you -configure the overrides on the server. +NOTE: A configuration system cannot force an application to use configuration data in any particular way. +Consequently, overrides are not enforceable. +However, they do provide useful default behavior for Spring Cloud Config clients. -You can change the priority of all overrides in the client to be more -like default values, allowing applications to supply their own values -in environment variables or System properties, by setting the flag -`spring.cloud.config.overrideNone=true` (default is false) in the -remote repository. +TIP: Normally, Spring environment placeholders with `${}` can be escaped (and resolved on the client) by using backslash (`\`) to escape the `$` or the `{`. +For example, `\${app.foo:bar}` resolves to `bar`, unless the app provides its own `app.foo`. + +NOTE: In YAML, you do not need to escape the backslash itself. +However, in properties files, you do need to escape the backslash, when you configure the overrides on the server. + +You can change the priority of all overrides in the client to be more like default values, letting applications supply their own values in environment variables or System properties, by setting the `spring.cloud.config.overrideNone=true` flag (the default is false) in the remote repository. === Health Indicator -Config Server comes with a Health Indicator that checks if the configured -`EnvironmentRepository` is working. By default it asks the `EnvironmentRepository` -for an application named `app`, the `default` profile and the default -label provided by the `EnvironmentRepository` implementation. +Config Server comes with a Health Indicator that checks whether the configured `EnvironmentRepository` is working. +By default, it asks the `EnvironmentRepository` for an application named `app`, the `default` profile, and the default label provided by the `EnvironmentRepository` implementation. -You can configure the Health Indicator to check more applications -along with custom profiles and custom labels, e.g. +You can configure the Health Indicator to check more applications along with custom profiles and custom labels, as shown in the following example: [source,yaml] ---- @@ -890,40 +750,22 @@ You can disable the Health Indicator by setting `spring.cloud.config.server.heal === Security -You are free to secure your Config Server in any way that makes sense -to you (from physical network security to OAuth2 bearer -tokens), and Spring Security and Spring Boot make it easy to do pretty -much anything. +You can secure your Config Server in any way that makes sense to you (from physical network security to OAuth2 bearer tokens), because Spring Security and Spring Boot offer support for many security arrangements. -To use the default Spring Boot configured HTTP Basic security, just -include Spring Security on the classpath (e.g. through -`spring-boot-starter-security`). The default is a username of "user" -and a randomly generated password, which isn't going to be very useful -in practice, so we recommend you configure the password (via -`spring.security.user.password`) and encrypt it (see below for instructions -on how to do that). +To use the default Spring Boot-configured HTTP Basic security, include Spring Security on the classpath (for example, through `spring-boot-starter-security`). +The default is a username of `user` and a randomly generated password. A random password is not useful in practice, so we recommend you configure the password (by setting `spring.security.user.password`) and encrypt it (see below for instructions on how to do that). === Encryption and Decryption -IMPORTANT: **Prerequisites:** to use the encryption and decryption features -you need the full-strength JCE installed in your JVM (it's not there by default). -You can download the "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files" -from Oracle, and follow instructions for installation (essentially replace the 2 policy files -in the JRE lib/security directory with the ones that you downloaded). +IMPORTANT: To use the encryption and decryption features you need the full-strength JCE installed in your JVM (it is not included by default). +You can download the "J`ava Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files`" from Oracle and follow the installation instructions (essentially, you need to replace the two policy files in the JRE lib/security directory with the ones that you downloaded). -If the remote property sources contain encrypted content (values -starting with `{cipher}`) they will be decrypted before sending to -clients over HTTP. The main advantage of this set up is that the -property values don't have to be in plain text when they are "at rest" -(e.g. in a git repository). If a value cannot be decrypted it is -removed from the property source and an additional property is added -with the same key, but prefixed with "invalid." and a value that means -"not applicable" (usually ""). This is largely to prevent cipher -text being used as a password and accidentally leaking. +If the remote property sources contain encrypted content (values starting with `{cipher}`), they are decrypted before sending to clients over HTTP. +The main advantage of this setup is that the property values need not be in plain text when they are "`at rest`" (for example, in a git repository). +If a value cannot be decrypted, it is removed from the property source and an additional property is added with the same key but prefixed with `invalid` and a value that means "`not applicable`" (usually ``). +This is largely to prevent cipher text being used as a password and accidentally leaking. -If you are setting up a remote config repository for config client -applications it might contain an `application.yml` like this, for -instance: +If you set up a remote config repository for config client applications, it might contain an `application.yml` similar to the following: .application.yml [source,yaml] @@ -934,7 +776,7 @@ spring: password: '{cipher}FKSAJDFGYOS8F7GLHAKERGFHLSAJ' ---- -Encrypted values in a .properties file must not be wrapped in quotes, otherwise the value will not be decrypted: +Encrypted values in a .properties file must not be wrapped in quotes. Otherwise, the value is not decrypted. The following example shows values that would work: .application.properties ---- @@ -942,54 +784,40 @@ spring.datasource.username: dbuser spring.datasource.password: {cipher}FKSAJDFGYOS8F7GLHAKERGFHLSAJ ---- -You can safely push this plain text to a shared git repository and the -secret password is protected. +You can safely push this plain text to a shared git repository, and the secret password remains protected. -The server also exposes `/encrypt` and `/decrypt` endpoints (on the -assumption that these will be secured and only accessed by authorized -agents). If you are editing a remote config file you can use the Config Server -to encrypt values by POSTing to the `/encrypt` endpoint, e.g. +The server also exposes `/encrypt` and `/decrypt` endpoints (on the assumption that these are secured and only accessed by authorized agents). +If you edit a remote config file, you can use the Config Server to encrypt values by POSTing to the `/encrypt` endpoint, as shown in the following example: ---- $ curl localhost:8888/encrypt -d mysecret 682bc583f4641835fa2db009355293665d2647dade3375c0ee201de2a49f7bda ---- -NOTE: If the value you are encrypting has characters in it that need to be URL encoded you should use -the `--data-urlencode` option to `curl` to make sure they are encoded properly. +NOTE: If the value you encrypt has characters in it that need to be URL encoded, you should use the `--data-urlencode` option to `curl` to make sure they are encoded properly. TIP: Be sure not to include any of the curl command statistics in the encrypted value. Outputting the value to a file can help avoid this problem. -The inverse operation is also available via `/decrypt` (provided the server is -configured with a symmetric key or a full key pair): +The inverse operation is also available through `/decrypt` (provided the server is +configured with a symmetric key or a full key pair), as shown in the following example: ---- $ curl localhost:8888/decrypt -d 682bc583f4641835fa2db009355293665d2647dade3375c0ee201de2a49f7bda mysecret ---- -TIP: If you are testing like this with curl, then use -`--data-urlencode` (instead of `-d`) or set an explicit `Content-Type: -text/plain` to make sure curl encodes the data correctly when there -are special characters ('+' is particularly tricky). +TIP: If you testing with curl, then use `--data-urlencode` (instead of `-d`) or set an explicit `Content-Type: text/plain` to make sure curl encodes the data correctly when there are special characters ('+' is particularly tricky). -Take the encrypted value and add the `{cipher}` prefix before you put -it in the YAML or properties file, and before you commit and push it -to a remote, potentially insecure store. +Take the encrypted value and add the `{cipher}` prefix before you put it in the YAML or properties file and before you commit and push it to a remote (potentially insecure) store. -The `/encrypt` and `/decrypt` endpoints also both accept paths of the -form `/*/{name}/{profiles}` which can be used to control cryptography -per application (name) and profile when clients call into the main -Environment resource. +The `/encrypt` and `/decrypt` endpoints also both accept paths in the form of `/*/{name}/{profiles}`, which can be used to control cryptography on a per-application (name) and per-profile basis when clients call into the main environment resource. -NOTE: to control the cryptography in this granular way you must also -provide a `@Bean` of type `TextEncryptorLocator` that creates a -different encryptor per name and profiles. The one that is provided -by default does not do this (so all encryptions use the same key). +NOTE: To control the cryptography in this granular way, you must also provide a `@Bean` of type `TextEncryptorLocator` that creates a different encryptor per name and profiles. +The one that is provided by default does not do so (all encryptions use the same key). The `spring` command line client (with Spring Cloud CLI extensions -installed) can also be used to encrypt and decrypt, e.g. +installed) can also be used to encrypt and decrypt, as shown in the following example: ---- $ spring encrypt mysecret --key foo @@ -998,50 +826,44 @@ $ spring decrypt --key foo 682bc583f4641835fa2db009355293665d2647dade3375c0ee201 mysecret ---- -To use a key in a file (e.g. an RSA public key for encryption) prepend -the key value with "@" and provide the file path, e.g. +To use a key in a file (such as an RSA public key for encryption), prepend +the key value with "@" and provide the file path, as shown in the following example: ---- $ spring encrypt mysecret --key @${HOME}/.ssh/id_rsa.pub AQAjPgt3eFZQXwt8tsHAVv/QHiY5sI2dRcR+... ---- -The key argument is mandatory (despite having a `--` prefix). +NOTE: The `--key` argument is mandatory (despite having a `--` prefix). === Key Management -The Config Server can use a symmetric (shared) key or an asymmetric -one (RSA key pair). The asymmetric choice is superior in terms of -security, but it is often more convenient to use a symmetric key since -it is just a single property value to configure in the `bootstrap.properties`. +The Config Server can use a symmetric (shared) key or an asymmetric one (RSA key pair). +The asymmetric choice is superior in terms of security, but it is often more convenient to use a symmetric key since it is a single property value to configure in the `bootstrap.properties`. -To configure a symmetric key you just need to set `encrypt.key` to a -secret String (or use an enviroment variable `ENCRYPT_KEY` to keep it -out of plain text configuration files). +To configure a symmetric key, you need to set `encrypt.key` to a secret String (or use the `ENCRYPT_KEY` environment variable to keep it out of plain-text configuration files). -To configure an asymmetric key you can either set the key as a -PEM-encoded text value (in `encrypt.key`), or via a keystore (e.g. as -created by the `keytool` utility that comes with the JDK). The -keystore properties are `encrypt.keyStore.\*` with `*` equal to +To configure an asymmetric key, you can either set the key as a PEM-encoded text value (in `encrypt.key`) or use a keystore (such as the keystore created by the `keytool` utility that comes with the JDK). +The following table describes the keystore properties: -* `location` (a `Resource` location), -* `password` (to unlock the keystore) and -* `alias` (to identify which key in the store is to be -used). +[options="header"] +|=== +^|Property ^|Description +|`encrypt.keyStore.location`|Contains a `Resource` location +|`encrypt.keyStore.password`|Holds the password that unlocks the keystore +|`encrypt.keyStore.alias`|Identifies which key in the store to use +|=== The encryption is done with the public key, and a private key is -needed for decryption. Thus in principle you can configure only the -public key in the server if you only want to do encryption (and are -prepared to decrypt the values yourself locally with the private -key). In practice you might not want to do that because it spreads the -key management process around all the clients, instead of -concentrating it in the server. On the other hand it's a useful option -if your config server really is relatively insecure and only a -handful of clients need the encrypted properties. +needed for decryption. +Thus, in principle, you can configure only the public key in the server if you want to only encrypt (and are prepared to decrypt the values yourself locally with the private key). +In practice, you might not want to do decrypt locally, because it spreads the key management process around all the clients, instead of +concentrating it in the server. +On the other hand, it can be a useful option if your config server is relatively insecure and only a handful of clients need the encrypted properties. === Creating a Key Store for Testing -To create a keystore for testing you can do something like this: +To create a keystore for testing, you can use a command resembling the following: ---- $ keytool -genkeypair -alias mytestkey -keyalg RSA \ @@ -1049,8 +871,8 @@ $ keytool -genkeypair -alias mytestkey -keyalg RSA \ -keypass changeme -keystore server.jks -storepass letmein ---- -Put the `server.jks` file in the classpath (for instance) and then in -your `bootstrap.yml` for the Config Server: +Put the `server.jks` file in the classpath (for instance) and then, in +your `bootstrap.yml`, for the Config Server, create the following settings: [source,yaml] ---- @@ -1064,14 +886,9 @@ encrypt: === Using Multiple Keys and Key Rotation -In addition to the `{cipher}` prefix in encrypted property values, the -Config Server looks for `{name:value}` prefixes (zero or many) before -the start of the (Base64 encoded) cipher text. The keys are passed to -a `TextEncryptorLocator` which can do whatever logic it needs to -locate a `TextEncryptor` for the cipher. If you have configured a -keystore (`encrypt.keystore.location`) the default locator will look -for keys in the store with aliases as supplied by the "key" prefix, -i.e. with a cipher text like this: +In addition to the `{cipher}` prefix in encrypted property values, the Config Server looks for zero or more `{name:value}` prefixes before the start of the (Base64 encoded) cipher text. +The keys are passed to a `TextEncryptorLocator`, which can do whatever logic it needs to locate a `TextEncryptor` for the cipher. +If you have configured a keystore (`encrypt.keystore.location`), the default locator looks for keys with aliases supplied by the `key` prefix, with a cipher text like resembling the following: [source,yaml] ---- @@ -1079,87 +896,49 @@ foo: bar: `{cipher}{key:testkey}...` ---- -the locator will look for a key named "testkey". A secret can also be -supplied via a `{secret:...}` value in the prefix, but if it is not -the default is to use the keystore password (which is what you get -when you build a keytore and don't specify a secret). If you *do* -supply a secret it is recommended that you also encrypt the secrets -using a custom `SecretLocator`. +The locator looks for a key named "testkey". +A secret can also be supplied by using a `{secret:...}` value in the prefix. +However, if it is not supplied, the default is to use the keystore password (which is what you get when you build a keytore and do not specify a secret). +If you do supply a secret, you should also encrypt the secret using a custom `SecretLocator`. -Key rotation is hardly ever necessary on cryptographic grounds if the -keys are only being used to encrypt a few bytes of configuration data -(i.e. they are not being used elsewhere), but occasionally you might -need to change the keys if there is a security breach for instance. In -that case all the clients would need to change their source config -files (e.g. in git) and use a new `{key:...}` prefix in all the -ciphers, checking beforehand of course that the key alias is available -in the Config Server keystore. +When the keys are being used only to encrypt a few bytes of configuration data (that is, they are not being used elsewhere), key rotation is hardly ever necessary on cryptographic grounds. +However, you might occasionally need to change the keys (for example, in the event of a security breach). +In that case, all the clients would need to change their source config files (for example, in git) and use a new `{key:...}` prefix in all the ciphers. +Note that the clients need to first check that the key alias is available in the Config Server keystore. -TIP: the `{name:value}` prefixes can also be added to plaintext posted -to the `/encrypt` endpoint, if you want to let the Config Server -handle all encryption as well as decryption. +TIP: If you want to let the Config Server handle all encryption as well as decryption, the `{name:value}` prefixes can also be added as plain text posted to the `/encrypt` endpoint, . === Serving Encrypted Properties -Sometimes you want the clients to decrypt the configuration locally, -instead of doing it in the server. In that case you can still have -/encrypt and /decrypt endpoints (if you provide the `encrypt.*` -configuration to locate a key), but you need to explicitly switch off -the decryption of outgoing properties using -`spring.cloud.config.server.encrypt.enabled=false`. If you don't care -about the endpoints, then it should work if you configure neither the -key nor the enabled flag. +Sometimes you want the clients to decrypt the configuration locally, instead of doing it in the server. +In that case, if you provide the `encrypt.*` configuration to locate a key, you can still have `/encrypt` and `/decrypt` endpoints, but you need to explicitly switch off the decryption of outgoing properties by setting `spring.cloud.config.server.encrypt.enabled=false`. +If you do not care about the endpoints, it should work if you do not configure either the key or the enabled flag. == Serving Alternative Formats -The default JSON format from the environment endpoints is perfect for -consumption by Spring applications because it maps directly onto the -`Environment` abstraction. If you prefer you can consume the same data -as YAML or Java properties by adding a suffix to the resource path -(".yml", ".yaml" or ".properties"). This can be useful for consumption -by applications that do not care about the structure of the JSON -endpoints, or the extra metadata they provide, for example an -application that is not using Spring might benefit from the simplicity -of this approach. +The default JSON format from the environment endpoints is perfect for consumption by Spring applications, because it maps directly onto the `Environment` abstraction. +If you prefer, you can consume the same data as YAML or Java properties by adding a suffix (".yml", ".yaml" or ".properties") to the resource path. +This can be useful for consumption by applications that do not care about the structure of the JSON endpoints or the extra metadata they provide (for example, an application that is not using Spring might benefit from the simplicity of this approach). -The YAML and properties representations have an additional flag -(provided as a boolean query parameter `resolvePlaceholders`) to -signal that placeholders in the source documents, in the standard -Spring `${...}` form, should be resolved in the output where possible -before rendering. This is a useful feature for consumers that don't -know about the Spring placeholder conventions. +The YAML and properties representations have an additional flag (provided as a boolean query parameter called `resolvePlaceholders`) to signal that placeholders in the source documents (in the standard Spring `${...}` form) should be resolved in the output before rendering, where possible. +This is a useful feature for consumers that do not know about the Spring placeholder conventions. -NOTE: there are limitations in using the YAML or properties formats, -mainly in relation to the loss of metadata. The JSON is structured as -an ordered list of property sources, for example, with names that -correlate with the source. The YAML and properties forms are coalesced -into a single map, even if the origin of the values has multiple -sources, and the names of the original source files are lost. The YAML -representation is not necessarily a faithful representation of the -YAML source in a backing repository either: it is constructed from a -list of flat property sources, and assumptions have to be made about -the form of the keys. +NOTE: There are limitations in using the YAML or properties formats, mainly in relation to the loss of metadata. +For example, the JSON is structured as an ordered list of property sources, with names that correlate with the source. +The YAML and properties forms are coalesced into a single map, even if the origin of the values has multiple sources, and the names of the original source files are lost. +Also, the YAML representation is not necessarily a faithful representation of the YAML source in a backing repository either. It is constructed from a list of flat property sources, and assumptions have to be made about the form of the keys. == Serving Plain Text -Instead of using the `Environment` abstraction (or one of the -alternative representations of it in YAML or properties format) your -applications might need generic plain text configuration files, -tailored to their environment. The Config Server provides these -through an additional endpoint at `/{name}/{profile}/{label}/{path}` -where "name", "profile" and "label" have the same meaning as the -regular environment endpoint, but "path" is a file name -(e.g. `log.xml`). The source files for this endpoint are located in -the same way as for the environment endpoints: the same search path is -used as for properties or YAML files, but instead of aggregating all -matching resources, only the first one to match is returned. +Instead of using the `Environment` abstraction (or one of the alternative representations of it in YAML or properties format), your applications might need generic plain-text configuration files that are tailored to their environment. +The Config Server provides these through an additional endpoint at `/{name}/{profile}/{label}/{path}`, where `name`, `profile`, and `label` have the same meaning as the regular environment endpoint, but `path` is a file name (such as `log.xml`). +The source files for this endpoint are located in the same way as for the environment endpoints. +The same search path is used for properties and YAML files. +However, instead of aggregating all matching resources, only the first one to match is returned. -After a resource is located, placeholders in the normal format -(`${...}`) are resolved using the effective `Environment` for the -application name, profile and label supplied. In this way the resource -endpoint is tightly integrated with the environment -endpoints. Example, if you have this layout for a GIT (or SVN) -repository: +After a resource is located, placeholders in the normal format (`${...}`) are resolved by using the effective `Environment` for the supplied application name, profile, and label. +In this way, the resource endpoint is tightly integrated with the environment endpoints. +Consider the following example for a GIT or SVN repository: ---- application.yml @@ -1190,7 +969,7 @@ nginx: name: develop.com ---- -then the `/foo/default/master/nginx.conf` resource looks like this: +The `/foo/default/master/nginx.conf` resource might be as follows: ---- server { @@ -1208,132 +987,83 @@ server { } ---- -NOTE: Just like the source files for environment configuration, the -"profile" is used to resolve the file name, so if you want a -profile-specific file then `/\*/development/*/logback.xml` will be -resolved by a file called `logback-development.xml` (in preference -to `logback.xml`). +NOTE: As with the source files for environment configuration, the `profile` is used to resolve the file name. +So, if you want a profile-specific file, `/\*/development/*/logback.xml` can be resolved by a file called `logback-development.xml` (in preference to `logback.xml`). -NOTE: If you do not want to supply the `label` and let the server use the default label, you can supply a `useDefaultLabel` request parameter. So, the above example for the `default` profile could look like `/foo/default/nginx.conf?useDefaultLabel`. +NOTE: If you do not want to supply the `label` and let the server use the default label, you can supply a `useDefaultLabel` request parameter. +So, the preceding example for the `default` profile could be `/foo/default/nginx.conf?useDefaultLabel`. == Embedding the Config Server -The Config Server runs best as a standalone application, but if you -need to you can embed it in another application. Just use the -`@EnableConfigServer` annotation. An optional property that can be -useful in this case is `spring.cloud.config.server.bootstrap` which is -a flag to indicate that the server should configure itself from its -own remote repository. The flag is off by default because it can delay -startup, but when embedded in another application it makes sense to -initialize the same way as any other application. +The Config Server runs best as a standalone application. +However, if need be, you can embed it in another application. +To do so, use the `@EnableConfigServer` annotation. +An optional property named `spring.cloud.config.server.bootstrap` can be useful in this case is. +It is a flag to indicate whether the server should configure itself from its own remote repository. +By default, the flag is off, because it can delay startup. +However, when embedded in another application, it makes sense to initialize the same way as any other application. -NOTE: It should be obvious, but remember that if you use the bootstrap -flag the config server will need to have its name and repository URI -configured in `bootstrap.yml`. +NOTE: If you use the bootstrap flag, the config server needs to have its name and repository URI configured in `bootstrap.yml`. -To change the location of the server endpoints you can (optionally) -set `spring.cloud.config.server.prefix`, e.g. "/config", to serve the -resources under a prefix. The prefix should start but not end with a -"/". It is applied to the `@RequestMappings` in the Config Server -(i.e. underneath the Spring Boot prefixes `server.servletPath` and -`server.contextPath`). +To change the location of the server endpoints, you can (optionally) set `spring.cloud.config.server.prefix` (for example, `/config`), to serve the resources under a prefix. +The prefix should start but not end with a `/`. +It is applied to the `@RequestMappings` in the Config Server (that is, underneath the Spring Boot `server.servletPath` and `server.contextPath` prefixes). -If you want to read the configuration for an application directly from -the backend repository (instead of from the config server) that's -basically an embedded config server with no endpoints. You can switch -off the endpoints entirely if you don't use the `@EnableConfigServer` -annotation (just set `spring.cloud.config.server.bootstrap=true`). +If you want to read the configuration for an application directly from the backend repository (instead of from the config server), you +basically wat an embedded config server with no endpoints. +You can switch off the endpoints entirely by not using the `@EnableConfigServer` annotation (set `spring.cloud.config.server.bootstrap=true`). == Push Notifications and Spring Cloud Bus -Many source code repository providers (like Github, Gitlab, Gitee or Bitbucket -for instance) will notify you of changes in a repository through a -webhook. You can configure the webhook via the provider's user -interface as a URL and a set of events in which you are -interested. For instance -https://developer.github.com/v3/activity/events/types/#pushevent[Github] -will POST to the webhook with a JSON body containing a list of -commits, and a header "X-Github-Event" equal to "push". If you add a -dependency on the `spring-cloud-config-monitor` library and activate -the Spring Cloud Bus in your Config Server, then a "/monitor" endpoint -is enabled. +Many source code repository providers (such as Github, Gitlab, Gitee, or Bitbucket) notify you of changes in a repository through a webhook. +You can configure the webhook through the provider's user interface as a URL and a set of events in which you are interested. +For instance, https://developer.github.com/v3/activity/events/types/#pushevent[Github] uses a POST to the webhook with a JSON body containing a list of commits and a header (`X-Github-Event`) set to `push`. +If you add a dependency on the `spring-cloud-config-monitor` library and activate the Spring Cloud Bus in your Config Server, then a `/monitor` endpoint is enabled. -When the webhook is activated the Config Server will send a -`RefreshRemoteApplicationEvent` targeted at the applications it thinks -might have changed. The change detection can be strategized, but by -default it just looks for changes in files that match the application -name (e.g. "foo.properties" is targeted at the "foo" application, and -"application.properties" is targeted at all applications). The strategy -if you want to override the behaviour is `PropertyPathNotificationExtractor` -which accepts the request headers and body as parameters and returns a list -of file paths that changed. +When the webhook is activated, the Config Server sends a `RefreshRemoteApplicationEvent` targeted at the applications it thinks might have changed. +The change detection can be strategized. +However, by default, it looks for changes in files that match the application name (for example, `foo.properties` is targeted at the `foo` application, while `application.properties` is targeted at all applications). +The strategy to use when you want to override the behavior is `PropertyPathNotificationExtractor`, which accepts the request headers and body as parameters and returns a list of file paths that changed. -The default configuration works out of the box with Github, Gitlab, Gitee or -Bitbucket. In addition to the JSON notifications from Github, Gitlab, Gitee -or Bitbucket you can trigger a change notification by POSTing to -"/monitor" with a form-encoded body parameters `path={name}`. This will -broadcast to applications matching the "{name}" pattern (can contain -wildcards). +The default configuration works out of the box with Github, Gitlab, Gitee, or Bitbucket. +In addition to the JSON notifications from Github, Gitlab, Gitee, or Bitbucket, you can trigger a change notification by POSTing to `/monitor` with form-encoded body parameters in the pattern of `path={name}`. +Doing so broadcasts to applications matching the `{name}` pattern (which can contain wildcards). -NOTE: the `RefreshRemoteApplicationEvent` will only be transmitted if -the `spring-cloud-bus` is activated in the Config Server and in the -client application. +NOTE: The `RefreshRemoteApplicationEvent` is transmitted only if the `spring-cloud-bus` is activated in both the Config Server and in the client application. -NOTE: the default configuration also detects filesystem changes in -local git repositories (the webhook is not used in that case but as -soon as you edit a config file a refresh will be broadcast). +NOTE: The default configuration also detects filesystem changes in local git repositories. In that case, the webhook is not used. However, as soon as you edit a config file, a refresh is broadcast. == Spring Cloud Config Client -A Spring Boot application can take immediate advantage of the Spring -Config Server (or other external property sources provided by the -application developer), and it will also pick up some additional -useful features related to `Environment` change events. +A Spring Boot application can take immediate advantage of the Spring Config Server (or other external property sources provided by the application developer). +It also picks up some additional useful features related to `Environment` change events. [[config-first-bootstrap]] === Config First Bootstrap -This is the default behaviour for any application which has the Spring -Cloud Config Client on the classpath. When a config client starts up -it binds to the Config Server (via the bootstrap configuration -property `spring.cloud.config.uri`) and initializes Spring -`Environment` with remote property sources. +The default behavior for any application that has the Spring Cloud Config Client on the classpath is as follows: +When a config client starts, it binds to the Config Server (through the `spring.cloud.config.uri` bootstrap configuration property) and initializes Spring `Environment` with remote property sources. -The net result of this is that all client apps that want to consume -the Config Server need a `bootstrap.yml` (or an environment variable) -with the server address in `spring.cloud.config.uri` (defaults to -"http://localhost:8888"). +The net result of this behavior is that all client applciations that want to consume the Config Server need a `bootstrap.yml` (or an environment variable) with the server address set in `spring.cloud.config.uri` (it defaults to "http://localhost:8888"). [[discovery-first-bootstrap]] === Discovery First Bootstrap -If you are using a `DiscoveryClient implementation, such as Spring Cloud Netflix -and Eureka Service Discovery or Spring Cloud Consul (Spring Cloud Zookeeper does -not support this yet), then you can have the Config Server register with the -Discovery Service if you want to, but in the default "Config First" mode, -clients won't be able to take advantage of the registration. +If you use a `DiscoveryClient implementation, such as Spring Cloud Netflix and Eureka Service Discovery or Spring Cloud Consul, you can have the Config Server register with the Discovery Service. +However, in the default "`Config First`" mode, clients cannot take advantage of the registration. -If you prefer to use `DiscoveryClient` to locate the Config Server, you can do -that by setting `spring.cloud.config.discovery.enabled=true` (default -"false"). The net result of that is that client apps all need a -`bootstrap.yml` (or an environment variable) with the appropriate discovery -configuration. For example, with Spring Cloud Netflix, you need to define the -Eureka server address, e.g. in `eureka.client.serviceUrl.defaultZone`. The -price for using this option is an extra network round trip on start up to -locate the service registration. The benefit is that the Config Server -can change its co-ordinates, as long as the Discovery Service is a fixed point. The -default service id is "configserver" but you can change that on the -client with `spring.cloud.config.discovery.serviceId` (and on the server -in the usual way for a service, e.g. by setting `spring.application.name`). +If you prefer to use `DiscoveryClient` to locate the Config Server, you can do so by setting `spring.cloud.config.discovery.enabled=true` (the default is `false`). +The net result of doing so is that client applications all need a `bootstrap.yml` (or an environment variable) with the appropriate discovery configuration. +For example, with Spring Cloud Netflix, you need to define the Eureka server address (for example, in `eureka.client.serviceUrl.defaultZone`). +The price for using this option is an extra network round trip on startup, to locate the service registration. +The benefit is that, as long as the Discovery Service is a fixed point, the Config Server can change its coordinates. +The default service ID is `configserver`, but you can change that on the client by setting `spring.cloud.config.discovery.serviceId` (and on the server, in the usual way for a service, such as by setting `spring.application.name`). -The discovery client implementations all support some kind of metadata -map (e.g. for Eureka we have `eureka.instance.metadataMap`). Some -additional properties of the Config Server may need to be configured -in its service registration metadata so that clients can connect -correctly. If the Config Server is secured with HTTP Basic you can -configure the credentials as "username" and "password". And if the -Config Server has a context path you can set "configPath". Example, -for a Config Server that is a Eureka client: +The discovery client implementations all support some kind of metadata map (for example, we have `eureka.instance.metadataMap` for Eureka). +Some additional properties of the Config Server may need to be configured in its service registration metadata so that clients can connect correctly. +If the Config Server is secured with HTTP Basic, you can configure the credentials as `username` and `password`. +Also, if the Config Server has a context path, you can set `configPath`. +For example, the following YAML file is for a Config Server that is a Eureka client: .bootstrap.yml [source,yaml] @@ -1351,51 +1081,41 @@ eureka: [[config-client-fail-fast]] === Config Client Fail Fast -In some cases, it may be desirable to fail startup of a service if -it cannot connect to the Config Server. If this is the desired -behavior, set the bootstrap configuration property -`spring.cloud.config.fail-fast=true` and the client will halt with -an Exception. +In some cases, you may want to fail startup of a service if it cannot connect to the Config Server. +If this is the desired behavior, set the bootstrap configuration property `spring.cloud.config.fail-fast=true` to make the client halt with an Exception. [[config-client-retry]] === Config Client Retry -If you expect that the config server may occasionally be unavailable when -your app starts, you can ask it to keep trying after a failure. First you need -to set `spring.cloud.config.fail-fast=true`, and then you need to add -`spring-retry` and `spring-boot-starter-aop` to your classpath. The default -behaviour is to retry 6 times with an initial backoff interval of 1000ms and an -exponential multiplier of 1.1 for subsequent backoffs. You can configure these -properties (and others) using `spring.cloud.config.retry.*` configuration properties. +If you expect that the config server may occasionally be unavailable when your application starts, you can make it keep trying after a failure. +First, you need to set `spring.cloud.config.fail-fast=true`. +Then you need to add `spring-retry` and `spring-boot-starter-aop` to your classpath. +The default behavior is to retry six times with an initial backoff interval of 1000ms and an exponential multiplier of 1.1 for subsequent backoffs. +You can configure these properties (and others) by setting the `spring.cloud.config.retry.*` configuration properties. -TIP: To take full control of the retry add a `@Bean` of type -`RetryOperationsInterceptor` with id "configServerRetryInterceptor". Spring -Retry has a `RetryInterceptorBuilder` that makes it easy to create one. +TIP: To take full control of the retry behavior, add a `@Bean` of type `RetryOperationsInterceptor` with an ID of `configServerRetryInterceptor`. +Spring Retry has a `RetryInterceptorBuilder` that supports creating one. === Locating Remote Configuration Resources -The Config Service serves property sources from `/{name}/{profile}/{label}`, where the default bindings in the client app are +The Config Service serves property sources from `/{name}/{profile}/{label}`, where the default bindings in the client app are as follows: * "name" = `${spring.application.name}` * "profile" = `${spring.profiles.active}` (actually `Environment.getActiveProfiles()`) * "label" = "master" -All of them can be overridden by setting `spring.cloud.config.\*` -(where `*` is "name", "profile" or "label"). The "label" is useful for -rolling back to previous versions of configuration; with the default -Config Server implementation it can be a git label, branch name or -commit id. Label can also be provided as a comma-separated list, in -which case the items in the list are tried on-by-one until one succeeds. -This can be useful when working on a feature branch, for instance, -when you might want to align the config label with your branch, but -make it optional (e.g. `spring.cloud.config.label=myfeature,develop`). +You can override all of them by setting `spring.cloud.config.\*` (where `*` is `name`, `profile` or `label`). +The `label` is useful for rolling back to previous versions of configuration. +With the default Config Server implementation, it can be a git label, branch name, or commit ID. +Label can also be provided as a comma-separated list. +In that case, the items in the list are tried one by one until one succeeds. +This behavior can be useful when working on a feature branch. +For instance, you might want to align the config label with your branch but make it optional (in that case, use `spring.cloud.config.label=myfeature,develop`). === Security -If you use HTTP Basic security on the server then clients just need to -know the password (and username if it isn't the default). You can do -that via the config server URI, or via separate username and password -properties, e.g. +If you use HTTP Basic security on the server, clients need to know the password (and username if it is not the default). +You can specify the username and password through the config server URI or via separate username and password properties, as shown in the following example: .bootstrap.yml [source,yaml] @@ -1406,7 +1126,7 @@ spring: uri: https://user:secret@myconfig.mycompany.com ---- -or +The following example shows an alternate way to pass the same information: .bootstrap.yml [source,yaml] @@ -1419,14 +1139,10 @@ spring: password: secret ---- -The `spring.cloud.config.password` and `spring.cloud.config.username` -values override anything that is provided in the URI. +The `spring.cloud.config.password` and `spring.cloud.config.username` values override anything that is provided in the URI. -If you deploy your apps on Cloud Foundry then the best way to provide -the password is through service credentials, e.g. in the URI, since -then it doesn't even need to be in a config file. An example which -works locally and for a user-provided service on Cloud Foundry named -"configserver": +If you deploy your apps on Cloud Foundry, the best way to provide the password is through service credentials (such as in the URI, since it does not need to be in a config file). +The following example works locally and for a user-provided service on Cloud Foundry named `configserver`: .bootstrap.yml [source,yaml] @@ -1438,23 +1154,24 @@ spring: ---- -If you use another form of security you might need to <> to the `ConfigServicePropertySourceLocator` (e.g. by -grabbing it in the bootstrap context and injecting one). +If you use another form of security, you might need to <> to the `ConfigServicePropertySourceLocator` (for example, by grabbing it in the bootstrap context and injecting it). ==== Health Indicator -The Config Client supplies a Spring Boot Health Indicator that attempts to load configuration from Config Server. The health indicator can be disabled by setting `health.config.enabled=false`. The response is also cached for performance reasons. The default cache time to live is 5 minutes. To change that value set the `health.config.time-to-live` property (in milliseconds). +The Config Client supplies a Spring Boot Health Indicator that attempts to load configuration from the Config Server. +The health indicator can be disabled by setting `health.config.enabled=false`. +The response is also cached for performance reasons. +The default cache time to live is 5 minutes. +To change that value, set the `health.config.time-to-live` property (in milliseconds). [[custom-rest-template]] ==== Providing A Custom RestTemplate -In some cases you might need to customize the requests made to the config server from -the client. Typically this involves passing special `Authorization` headers to -authenticate requests to the server. To provide a custom `RestTemplate` follow the -steps below. +In some cases, you might need to customize the requests made to the config server from the client. +Typically, doing so involves passing special `Authorization` headers to authenticate requests to the server. +To provide a custom `RestTemplate`: -1. Create a new configuration bean with an implementation of `PropertySourceLocator`. +1. Create a new configuration bean with an implementation of `PropertySourceLocator`, as shown in the following example: .CustomConfigServiceBootstrapConfiguration.java [source,java] @@ -1471,8 +1188,8 @@ public class CustomConfigServiceBootstrapConfiguration { } ---- -2. In `resources/META-INF` create a file called -`spring.factories` and specify your custom configuration. +2. In `resources/META-INF`, create a file called +`spring.factories` and specify your custom configuration, as shown in the following example: .spring.factories [source,properties] @@ -1482,10 +1199,9 @@ org.springframework.cloud.bootstrap.BootstrapConfiguration = com.my.config.clien ==== Vault -When using Vault as a backend to your config server the client will need to -supply a token for the server to retrieve values from Vault. This token -can be provided within the client by setting `spring.cloud.config.token` -in `bootstrap.yml`. +When using Vault as a backend to your config server, the client needs to supply a token for the server to retrieve values from Vault. +This token can be provided within the client by setting `spring.cloud.config.token` +in `bootstrap.yml`, as shown in the following example: .bootstrap.yml [source,yaml] @@ -1496,16 +1212,14 @@ spring: token: YourVaultToken ---- -=== Vault +=== Nested Keys In Vault -==== Nested Keys In Vault - -Vault supports the ability to nest keys in a value stored in Vault. For example +Vault supports the ability to nest keys in a value stored in Vault, as shown in the following example: `echo -n '{"appA": {"secret": "appAsecret"}, "bar": "baz"}' | vault write secret/myapp -` -This command will write a JSON object to your Vault. To access these values in Spring -you would use the traditional dot(.) annotation. For example +This command writes a JSON object to your Vault. +To access these values in Spring, you would use the traditional dot(`.`) annotation, as shown in the following example [source,java] ---- @@ -1513,4 +1227,4 @@ you would use the traditional dot(.) annotation. For example String name = "World"; ---- -The above code would set the `name` variable to `appAsecret`. +The preceding code would sets the value of the `name` variable to `appAsecret`.