AWS Lambda
+The AWS adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.
+The adapter has a couple of generic request handlers that you can use. The most generic is SpringBootStreamHandler, which uses a Jackson ObjectMapper provided by Spring Boot to serialize and deserialize the objects in the function. There is also a SpringBootRequestHandler which you can extend, and provide the input and output types as type parameters (enabling AWS to inspect the class and do the JSON conversions itself).
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name (e.g. as FUNCTION_NAME environment variable in AWS). The functions are extracted from the Spring Cloud FunctionCatalog (searching first for Function then Consumer and finally Supplier).
Notes on JAR Layout
-Notes on JAR Layout
You don’t need the Spring Cloud Function Web or Stream adapter at runtime in Lambda, so you might need to exclude those before you create the JAR you send to AWS. A Lambda application has to be @@ -164,16 +159,14 @@ then additional transformers must be configured as part of the maven-shade-plugi
Build file setup
-Build file setup
In order to run Spring Cloud Function applications on AWS Lambda, you can leverage Maven or Gradle plugins offered by the cloud platform provider.
Maven
+Maven
In order to use the adapter plugin for Maven, add the plugin dependency to your pom.xml
file:
Upload
-Upload
Build the sample under spring-cloud-function-samples/function-sample-aws and upload the -aws jar file to Lambda. The handler can be example.Handler or org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler (FQN of the class, not a method reference, although Lambda does accept method references).
Application
Type Conversion
-Type Conversion
Spring Cloud Function will attempt to transparently handle type conversion between the raw input stream and types declared by your function.
@@ -345,8 +334,8 @@ incoming stream event to an instance ofFoo.
In the event type is not known or can not be determined (e.g., Function<?, ?>) we will attempt to
convert an incoming stream event to a generic Map.
Raw Input
+Raw Input
There are times when you may want to have access to a raw input. In this case all you need is to declare your
function signature to accept InputStream. For example, Function<InputStream, ?>. In this case
diff --git a/reference/html/aws-readme.html b/reference/html/aws-readme.html
index 381a98dd7..08dc90659 100644
--- a/reference/html/aws-readme.html
+++ b/reference/html/aws-readme.html
@@ -5,9 +5,10 @@
-
-
-
- Notes on JAR Layout -
- Build file setup - -
- Upload -
- Type Conversion
-
-
-
- Raw Input -
+ - AWS Lambda
This project provides an adapter layer for a Spring Cloud Function application onto AWS Lambda. You can write an app with a single @Bean of type Function, Consumer or Supplier and it will be deployable in AWS if you get the JAR file laid out right. The best way to make it work is to include spring-cloud-function-context as a dependency, but not the higher level adapters (e.g. spring-cloud-function-stream).
AWS Lambda
+The AWS adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.
+The adapter has a couple of generic request handlers that you can use. The most generic is SpringBootStreamHandler, which uses a Jackson ObjectMapper provided by Spring Boot to serialize and deserialize the objects in the function. There is also a SpringBootRequestHandler which you can extend, and provide the input and output types as type parameters (enabling AWS to inspect the class and do the JSON conversions itself).
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name (e.g. as FUNCTION_NAME environment variable in AWS). The functions are extracted from the Spring Cloud FunctionCatalog (searching first for Function then Consumer and finally Supplier).
Notes on JAR Layout
-Notes on JAR Layout
You don’t need the Spring Cloud Function Web or Stream adapter at runtime in Lambda, so you might need to exclude those before you create the JAR you send to AWS. A Lambda application has to be @@ -167,16 +166,14 @@ then additional transformers must be configured as part of the maven-shade-plugi
Build file setup
-Build file setup
In order to run Spring Cloud Function applications on AWS Lambda, you can leverage Maven or Gradle plugins offered by the cloud platform provider.
Maven
+Maven
In order to use the adapter plugin for Maven, add the plugin dependency to your pom.xml
file:
Upload
-Upload
Build the sample under spring-cloud-function-samples/function-sample-aws and upload the -aws jar file to Lambda. The handler can be example.Handler or org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler (FQN of the class, not a method reference, although Lambda does accept method references).
Application
Type Conversion
-Type Conversion
Spring Cloud Function will attempt to transparently handle type conversion between the raw input stream and types declared by your function.
@@ -348,8 +341,8 @@ incoming stream event to an instance ofFoo.
In the event type is not known or can not be determined (e.g., Function<?, ?>) we will attempt to
convert an incoming stream event to a generic Map.
Raw Input
+Raw Input
There are times when you may want to have access to a raw input. In this case all you need is to declare your
function signature to accept InputStream. For example, Function<InputStream, ?>. In this case
diff --git a/reference/html/aws.html b/reference/html/aws.html
index 060df3ccd..613f43392 100644
--- a/reference/html/aws.html
+++ b/reference/html/aws.html
@@ -8,6 +8,7 @@
-
-
- Introduction -
- Notes on JAR Layout -
- Build file setup +
- Introduction - -
- Upload -
- Type Conversion -
- Functional Bean Definitions @@ -118,9 +116,6 @@ $(addBlockSwitches);
- Introduction -
- Getting Started -
- Building and Running a Function -
- Function Catalog and Flexible Function Signatures - - -
- Standalone Web Applications -
- Standalone Streaming Applications -
- Deploying a Packaged Function -
- Functional Bean Definitions - - -
- Dynamic Compilation -
- Serverless Platform Adapters -
-
-
Promote the implementation of business logic via functions.
-
- -
-
Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.
-
- -
-
Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).
-
- -
-
Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.
-
- -
-
Wrappers for
-@Beansof typeFunction,Consumerand -Supplier, exposing them to the outside world as either HTTP -endpoints and/or message stream listeners/publishers with RabbitMQ, Kafka etc.
- -
-
Compiling strings which are Java function bodies into bytecode, and -then turning them into
-@Beansthat can be wrapped as above.
- -
-
Deploying a JAR file containing such an application context with an -isolated classloader, so that you can pack them together in a single -JVM.
-
- -
-
Adapters for AWS Lambda, Azure, Apache OpenWhisk and possibly other "serverless" service providers.
-
- -
-
The main class is an
-ApplicationContextInitializer.
- -
-
The
-@Beanmethods have been converted to calls tocontext.registerBean()
- -
-
The
-@SpringBootApplicationhas been replaced with -@SpringBootConfigurationto signify that we are not enabling Spring -Boot autoconfiguration, and yet still marking the class as an "entry -point".
- -
-
The
-SpringApplicationfrom Spring Boot has been replaced with a -FunctionalSpringApplicationfrom Spring Cloud Function (it’s a -subclass).
- - Dynamic Compilation -
- Serverless Platform Adapters +
- Serverless Platform Adapters + +
3.0.0.BUILD-SNAPSHOT
The AWS adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.
Introduction
AWS Lambda
+The AWS adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.
+The adapter has a couple of generic request handlers that you can use. The most generic is SpringBootStreamHandler, which uses a Jackson ObjectMapper provided by Spring Boot to serialize and deserialize the objects in the function. There is also a SpringBootRequestHandler which you can extend, and provide the input and output types as type parameters (enabling AWS to inspect the class and do the JSON conversions itself).
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name (e.g. as FUNCTION_NAME environment variable in AWS). The functions are extracted from the Spring Cloud FunctionCatalog (searching first for Function then Consumer and finally Supplier).
Notes on JAR Layout
-Notes on JAR Layout
You don’t need the Spring Cloud Function Web or Stream adapter at runtime in Lambda, so you might need to exclude those before you create the JAR you send to AWS. A Lambda application has to be @@ -186,16 +183,14 @@ then additional transformers must be configured as part of the maven-shade-plugi
Build file setup
-Build file setup
In order to run Spring Cloud Function applications on AWS Lambda, you can leverage Maven or Gradle plugins offered by the cloud platform provider.
Maven
+Maven
In order to use the adapter plugin for Maven, add the plugin dependency to your pom.xml
file:
Upload
-Upload
Build the sample under spring-cloud-function-samples/function-sample-aws and upload the -aws jar file to Lambda. The handler can be example.Handler or org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler (FQN of the class, not a method reference, although Lambda does accept method references).
Application
Type Conversion
-Type Conversion
Spring Cloud Function will attempt to transparently handle type conversion between the raw input stream and types declared by your function.
@@ -367,8 +358,8 @@ incoming stream event to an instance ofFoo.
In the event type is not known or can not be determined (e.g., Function<?, ?>) we will attempt to
convert an incoming stream event to a generic Map.
Raw Input
+Raw Input
There are times when you may want to have access to a raw input. In this case all you need is to declare your
function signature to accept InputStream. For example, Function<InputStream, ?>. In this case
@@ -377,6 +368,8 @@ we will not attempt any conversion and will pass the raw input directly to a fun
Functional Bean Definitions
Microsoft Azure
+The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
You can write an app with a single @Bean of type Function and it will be deployable in Azure if you get the JAR file laid out right.
@Bean of type Function
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name. Or if you make the @FunctionName in the Azure handler method match the function name it should work that way (also for function apps with multiple functions). The functions are extracted from the Spring Cloud FunctionCatalog so the default function names are the same as the bean names.
Accessing Azure ExecutionContext
+Accessing Azure ExecutionContext
Some time there is a need to access the target execution context provided by Azure runtime in the form of com.microsoft.azure.functions.ExecutionContext.
For example one of such needs is logging, so it can appear in the Azure console.
Normally type-based injection should suffice, however if need to you can also utilise the bean name under which it is registered which is targetExecutionContext.
Notes on JAR Layout
+Notes on JAR Layout
You don’t need the Spring Cloud Function Web at runtime in Azure, so you can exclude this before you create the JAR you deploy to Azure, but it won’t be used if you include it, so @@ -168,9 +172,8 @@ it doesn’t hurt to leave it in. A function application on Azure is an arch The dependencies should not be included.
Build file setup
-Build file setup
In order to run Spring Cloud Function applications on Microsoft Azure, you can leverage the Maven plugin offered by the cloud platform provider.
@@ -222,7 +225,7 @@ Azure functions staging directory (see theYou can find the entire sample pom.xml file for deploying Spring Cloud Function
-applications to Microsoft Azure with Maven here.
Build
-Build
./mvnw -U clean package
Running the sample
-Running the sample
You can run the sample locally, just like the other Spring Cloud Function samples:
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
You can write an app with a single @Bean of type Function and it will be deployable in Azure if you get the JAR file laid out right.
Microsoft Azure
+The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
You can write an app with a single @Bean of type Function and it will be deployable in Azure if you get the JAR file laid out right.
@Bean of type Function
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name. Or if you make the @FunctionName in the Azure handler method match the function name it should work that way (also for function apps with multiple functions). The functions are extracted from the Spring Cloud FunctionCatalog so the default function names are the same as the bean names.
Accessing Azure ExecutionContext
+Accessing Azure ExecutionContext
Some time there is a need to access the target execution context provided by Azure runtime in the form of com.microsoft.azure.functions.ExecutionContext.
For example one of such needs is logging, so it can appear in the Azure console.
Normally type-based injection should suffice, however if need to you can also utilise the bean name under which it is registered which is targetExecutionContext.
Notes on JAR Layout
+Notes on JAR Layout
You don’t need the Spring Cloud Function Web at runtime in Azure, so you can exclude this before you create the JAR you deploy to Azure, but it won’t be used if you include it, so @@ -173,9 +181,8 @@ it doesn’t hurt to leave it in. A function application on Azure is an arch The dependencies should not be included.
Build file setup
-Build file setup
In order to run Spring Cloud Function applications on Microsoft Azure, you can leverage the Maven plugin offered by the cloud platform provider.
@@ -227,7 +234,7 @@ Azure functions staging directory (see theYou can find the entire sample pom.xml file for deploying Spring Cloud Function
-applications to Microsoft Azure with Maven here.
Build
-Build
./mvnw -U clean package
Running the sample
-Running the sample
You can run the sample locally, just like the other Spring Cloud Function samples:
3.0.0.BUILD-SNAPSHOT
https://cloud.spring.io/spring-cloud-function/home.html
+The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
Microsoft Azure
The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
@Bean of type Function
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name. Or if you make the @FunctionName in the Azure handler method match the function name it should work that way (also for function apps with multiple functions). The functions are extracted from the Spring Cloud FunctionCatalog so the default function names are the same as the bean names.
Accessing Azure ExecutionContext
+Accessing Azure ExecutionContext
Some time there is a need to access the target execution context provided by Azure runtime in the form of com.microsoft.azure.functions.ExecutionContext.
For example one of such needs is logging, so it can appear in the Azure console.
Normally type-based injection should suffice, however if need to you can also utilise the bean name under which it is registered which is targetExecutionContext.
Notes on JAR Layout
+Notes on JAR Layout
You don’t need the Spring Cloud Function Web at runtime in Azure, so you can exclude this before you create the JAR you deploy to Azure, but it won’t be used if you include it, so @@ -177,9 +182,8 @@ it doesn’t hurt to leave it in. A function application on Azure is an arch The dependencies should not be included.
Build file setup
-Build file setup
In order to run Spring Cloud Function applications on Microsoft Azure, you can leverage the Maven plugin offered by the cloud platform provider.
@@ -231,7 +235,7 @@ Azure functions staging directory (see theYou can find the entire sample pom.xml file for deploying Spring Cloud Function
-applications to Microsoft Azure with Maven here.
Build
-Build
./mvnw -U clean package
Running the sample
-Running the sample
You can run the sample locally, just like the other Spring Cloud Function samples:
Spring Cloud Function
--
-
Spring Cloud Function Reference Documentation
+Mark Fisher, Dave Syer, Oleg Zhurakousky, Anshul Mehra
-3.0.0.BUILD-SNAPSHOT
- -
Introduction
-Spring Cloud Function is a project with the following high-level goals:
+The reference documentation consists of the following sections:
-
-
It abstracts away all of the transport details and -infrastructure, allowing the developer to keep all the familiar tools -and processes, and focus firmly on business logic.
-Here’s a complete, executable, testable Spring Boot application -(implementing a simple string manipulation):
-@SpringBootApplication
-public class Application {
-
- @Bean
- public Function<Flux<String>, Flux<String>> uppercase() {
- return flux -> flux.map(value -> value.toUpperCase());
- }
-
- public static void main(String[] args) {
- SpringApplication.run(Application.class, args);
- }
-}It’s just a Spring Boot application, so it can be built, run and
-tested, locally and in a CI build, the same way as any other Spring
-Boot application. The Function is from java.util and Flux is a
-Reactive Streams Publisher from
-Project Reactor. The function can be
-accessed over HTTP or messaging.
Spring Cloud Function has 4 main features:
--
-
| - + | +Reference Guide | --Spring Cloud is released under the non-restrictive Apache 2.0 license. If you would like to contribute to this section of the documentation or if you find an error, please find the source code and issue trackers in the project at github. + |
+ Spring Cloud Function Reference + |
+
| +AWS Adapter + | +
+ AWS Adapter Reference + |
+||
| +Azure Adapter + | +
+ Azure Adapter Reference + |
+||
| +Apache OpenWhisk Adapter + | +
+ Apache OpenWhisk Adapter Reference |
Getting Started
-Build from the command line (and "install" the samples):
+Relevant Links:
$ ./mvnw clean install-
(If you like to YOLO add -DskipTests.)
Run one of the samples, e.g.
-$ java -jar spring-cloud-function-samples/function-sample/target/*.jar-
This runs the app and exposes its functions over HTTP, so you can -convert a string to uppercase, like this:
-$ curl -H "Content-Type: text/plain" localhost:8080/uppercase -d Hello -HELLO-
You can convert multiple strings (a Flux<String>) by separating them
-with new lines
$ curl -H "Content-Type: text/plain" localhost:8080/uppercase -d 'Hello -> World' -HELLOWORLD-
(You can use QJ in a terminal to insert a new line in a literal
-string like that.)
Building and Running a Function
-The sample @SpringBootApplication above has a function that can be
-decorated at runtime by Spring Cloud Function to be an HTTP endpoint,
-or a Stream processor, for instance with RabbitMQ, Apache Kafka or
-JMS.
The @Beans can be Function, Consumer or Supplier (all from
-java.util), and their parametric types can be String or POJO.
Functions can also be of Flux<String> or Flux<Pojo> and Spring
-Cloud Function takes care of converting the data to and from the
-desired types, as long as it comes in as plain text or (in the case of
-the POJO) JSON. There is also support for Message<Pojo> where the
-message headers are copied from the incoming event, depending on the
-adapter. The web adapter also supports conversion from form-encoded
-data to a Map, and if you are using the function with Spring Cloud
-Stream then all the conversion and coercion features for message
-payloads will be applicable as well.
Functions can be grouped together in a single application, or deployed -one-per-jar. It’s up to the developer to choose. An app with multiple -functions can be deployed multiple times in different "personalities", -exposing different functions over different physical transports.
-Function Catalog and Flexible Function Signatures
-One of the main features of Spring Cloud Function is to adapt and support a range of type signatures for user-defined functions,
-while providing a consistent execution model.
-That’s why all user defined functions are transformed into a canonical representation by FunctionCatalog, using primitives
-defined by the Project Reactor (i.e., Flux<T> and Mono<T>).
-Users can supply a bean of type Function<String,String>, for instance, and the FunctionCatalog will wrap it into a
-Function<Flux<String>,Flux<String>>.
Using Reactor based primitives not only helps with the canonical representation of user defined functions, but it also -facilitates a more robust and flexible(reactive) execution model.
-While users don’t normally have to care about the FunctionCatalog at all, it is useful to know what
-kind of functions are supported in user code.
Java 8 function support
-Generally speaking users can expect that if they write a function for
-a plain old Java type (or primitive wrapper), then the function
-catalog will wrap it to a Flux of the same type. If the user writes
-a function using Message (from spring-messaging) it will receive and
-transmit headers from any adapter that supports key-value metadata
-(e.g. HTTP headers). Here are the details.
| User Function | -Catalog Registration | -- |
|---|---|---|
|
-
|
-- |
|
-
|
-- |
|
-
|
-- |
|
-
|
-- |
|
-
|
-- |
|
-
|
-- |
|
-
|
-- |
|
-
|
-- |
Consumer is a little bit special because it has a void return type,
-which implies blocking, at least potentially. Most likely you will not
-need to write Consumer<Flux<?>>, but if you do need to do that,
-remember to subscribe to the input flux. If you declare a Consumer
-of a non publisher type (which is normal), it will be converted to a
-function that returns a publisher, so that it can be subscribed to in
-a controlled way.
Function Component Scan
-Spring Cloud Function will scan for implementations of Function,
-Consumer and Supplier in a package called functions if it
-exists. Using this feature you can write functions that have no
-dependencies on Spring - not even the @Component annotation is
-needed. If you want to use a different package, you can set
-spring.cloud.function.scan.packages. You can also use
-spring.cloud.function.scan.enabled=false to switch off the scan
-completely.
Function Routing
-Since version 2.2 Spring Cloud Function provides routing feature allowing -you to invoke a single function which acts as a router to an actual function you wish to invoke -This feature is very useful in certain FAAS environments where maintaining configurations -for several functions could be cumbersome or exposing more then one function is not possible.
-You enable this feature via spring.cloud.function.routing.enabled property setting it
-to true (default is false).
-This enables RoutingFunction under the name router which is loaded in FunctionCatalog.
This function has the following signature:
-public class RoutingFunction implements Function<Publisher<Message<?>>, Publisher<?>>, Consumer<Publisher<Message<?>>> {
-. . .
-}This allows the above function to act as both Function and Consumer.
-As you can see it takes Message<?> as an input argument. This allows you to communicate
-the name of the actual function you want to invoke by providing function.name Message header.
In specific execution environments/models the adapters are responsible to translate and communicate function.name
-via Message header. For example, when using spring-cloud-function-web you can provide function.name as an HTTP
-header and the framework will propagate it as well as other HTTP headers as Message headers.
Using Message also allows us to benefit from `MessageConverter`s to convert incoming request to the actual input type -of the target function
-Kotlin Lambda support
-We also provide support for Kotlin lambdas (since v2.0). -Consider the following:
-@Bean
-open fun kotlinSupplier(): () -> String {
- return { "Hello from Kotlin" }
-}
-
-@Bean
-open fun kotlinFunction(): (String) -> String {
- return { it.toUpperCase() }
-}
-
-@Bean
-open fun kotlinConsumer(): (String) -> Unit {
- return { println(it) }
-}The above represents Kotlin lambdas configured as Spring beans. The signature of each maps to a Java equivalent of
-Supplier, Function and Consumer, and thus supported/recognized signatures by the framework.
-While mechanics of Kotlin-to-Java mapping are outside of the scope of this documentation, it is important to understand that the
-same rules for signature transformation outlined in "Java 8 function support" section are applied here as well.
To enable Kotlin support all you need is to add spring-cloud-function-kotlin module to your classpath which contains the appropriate
-autoconfiguration and supporting classes.
Standalone Web Applications
-The spring-cloud-function-web module has autoconfiguration that
-activates when it is included in a Spring Boot web application (with
-MVC support). There is also a spring-cloud-starter-function-web to
-collect all the optional dependencies in case you just want a simple
-getting started experience.
With the web configurations activated your app will have an MVC
-endpoint (on "/" by default, but configurable with
-spring.cloud.function.web.path) that can be used to access the
-functions in the application context. The supported content types are
-plain text and JSON.
| Method | -Path | -Request | -Response | -Status | -
|---|---|---|---|---|
GET |
-/{supplier} |
-- |
-Items from the named supplier |
-200 OK |
-
POST |
-/{consumer} |
-JSON object or text |
-Mirrors input and pushes request body into consumer |
-202 Accepted |
-
POST |
-/{consumer} |
-JSON array or text with new lines |
-Mirrors input and pushes body into consumer one by one |
-202 Accepted |
-
POST |
-/{function} |
-JSON object or text |
-The result of applying the named function |
-200 OK |
-
POST |
-/{function} |
-JSON array or text with new lines |
-The result of applying the named function |
-200 OK |
-
GET |
-/{function}/{item} |
-- |
-Convert the item into an object and return the result of applying the function |
-200 OK |
-
As the table above shows the behaviour of the endpoint depends on the method and also the type of incoming request data. When the incoming data is single valued, and the target function is declared as obviously single valued (i.e. not returning a collection or Flux), then the response will also contain a single value.
-For multi-valued responses the client can ask for a server-sent event stream by sending `Accept: text/event-stream".
If there is only a single function (consumer etc.) in the catalog, the name in the path is optional. -Composite functions can be addressed using pipes or commas to separate function names (pipes are legal in URL paths, but a bit awkward to type on the command line).
-For cases where there is more then a single function in catalog and you want to map a specific function to the root
-path (e.g., "/"), or you want to compose several functions and then map to the root path you can do so by providing
-spring.cloud.function.definition property which essentially used by spring-=cloud-function-web module to provide
-default mapping for cases where there is some type of a conflict (e.g., more then one function available etc).
For example,
---spring.cloud.function.definition=foo|bar-
The above property will compose 'foo' and 'bar' function and map the composed function to the "/" path.
-Functions and consumers that are declared with input and output in Message<?> will see the request headers on the input messages, and the output message headers will be converted to HTTP headers.
When POSTing text the response format might be different with Spring Boot 2.0 and older versions, depending on the content negotiation (provide content type and accpt headers for the best results).
-Standalone Streaming Applications
-To send or receive messages from a broker (such as RabbitMQ or Kafka) you can leverage spring-cloud-stream project and it’s integration with Spring Cloud Function.
-Please refer to Spring Cloud Function section of the Spring Cloud Stream reference manual for more details and examples.
Deploying a Packaged Function
-Spring Cloud Function provides a "deployer" library that allows you to launch a jar file (or exploded archive, or set of jar files) with an isolated class loader and expose the functions defined in it. This is quite a powerful tool that would allow you to, for instance, adapt a function to a range of different input-output adapters without changing the target jar file. Serverless platforms often have this kind of feature built in, so you could see it as a building block for a function invoker in such a platform (indeed the Riff Java function invoker uses this library).
-The standard entry point of the API is the Spring configuration annotation @EnableFunctionDeployer. If that is used in a Spring Boot application the deployer kicks in and looks for some configuration to tell it where to find the function jar. At a minimum the user has to provide a function.location which is a URL or resource location for the archive containing the functions. It can optionally use a maven: prefix to locate the artifact via a dependency lookup (see FunctionProperties for complete details). A Spring Boot application is bootstrapped from the jar file, using the MANIFEST.MF to locate a start class, so that a standard Spring Boot fat jar works well, for example. If the target jar can be launched successfully then the result is a function registered in the main application’s FunctionCatalog. The registered function can be applied by code in the main application, even though it was created in an isolated class loader (by deault).
Functional Bean Definitions
-Spring Cloud Function supports a "functional" style of bean declarations for small apps where you need fast startup. The functional style of bean declaration was a feature of Spring Framework 5.0 with significant enhancements in 5.1.
-Comparing Functional with Traditional Bean Definitions
-Here’s a vanilla Spring Cloud Function application from with the
-familiar @Configuration and @Bean declaration style:
@SpringBootApplication
-public class DemoApplication {
-
- @Bean
- public Function<String, String> uppercase() {
- return value -> value.toUpperCase();
- }
-
- public static void main(String[] args) {
- SpringApplication.run(DemoApplication.class, args);
- }
-
-}You can run the above in a serverless platform, like AWS Lambda or Azure Functions, or you can run it in its own HTTP server just by including spring-cloud-function-starter-web on the classpath. Running the main method would expose an endpoint that you can use to ping that uppercase function:
$ curl localhost:8080 -d foo
-FOOThe web adapter in spring-cloud-function-starter-web uses Spring MVC, so you needed a Servlet container. You can also use Webflux where the default server is netty (even though you can still use Servlet containers if you want to) - just include the spring-cloud-starter-function-webflux dependency instead. The functionality is the same, and the user application code can be used in both.
Now for the functional beans: the user application code can be recast into "functional" -form, like this:
-@SpringBootConfiguration
-public class DemoApplication implements ApplicationContextInitializer<GenericApplicationContext> {
-
- public static void main(String[] args) {
- FunctionalSpringApplication.run(DemoApplication.class, args);
- }
-
- public Function<String, String> uppercase() {
- return value -> value.toUpperCase();
- }
-
- @Override
- public void initialize(GenericApplicationContext context) {
- context.registerBean("demo", FunctionRegistration.class,
- () -> new FunctionRegistration<>(uppercase())
- .type(FunctionType.from(String.class).to(String.class)));
- }
-
-}The main differences are:
--
-
The business logic beans that you register in a Spring Cloud Function app are of type FunctionRegistration. This is a wrapper that contains both the function and information about the input and output types. In the @Bean form of the application that information can be derived reflectively, but in a functional bean registration some of it is lost unless we use a FunctionRegistration.
An alternative to using an ApplicationContextInitializer and FunctionRegistration is to make the application itself implement Function (or Consumer or Supplier). Example (equivalent to the above):
@SpringBootConfiguration
-public class DemoApplication implements Function<String, String> {
-
- public static void main(String[] args) {
- FunctionalSpringApplication.run(DemoApplication.class, args);
- }
-
- @Override
- public String uppercase(String value) {
- return value.toUpperCase();
- }
-
-}It would also work if you add a separate, standalone class of type Function and register it with the SpringApplication using an alternative form of the run() method. The main thing is that the generic type information is available at runtime through the class declaration.
The app runs in its own HTTP server if you add spring-cloud-starter-function-webflux (it won’t work with the MVC starter at the moment because the functional form of the embedded Servlet container hasn’t been implemented). The app also runs just fine in AWS Lambda or Azure Functions, and the improvements in startup time are dramatic.
Testing Functional Applications
-Spring Cloud Function also has some utilities for integration testing that will be very familiar to Spring Boot users. For example, here is an integration test for the HTTP server wrapping the app above:
-@RunWith(SpringRunner.class)
-@FunctionalSpringBootTest
-@AutoConfigureWebTestClient
-public class FunctionalTests {
-
- @Autowired
- private WebTestClient client;
-
- @Test
- public void words() throws Exception {
- client.post().uri("/").body(Mono.just("foo"), String.class).exchange()
- .expectStatus().isOk().expectBody(String.class).isEqualTo("FOO");
- }
-
-}This test is almost identical to the one you would write for the @Bean version of the same app - the only difference is the @FunctionalSpringBootTest annotation, instead of the regular @SpringBootTest. All the other pieces, like the @Autowired WebTestClient, are standard Spring Boot features.
Or you could write a test for a non-HTTP app using just the FunctionCatalog. For example:
@RunWith(SpringRunner.class)
-@FunctionalSpringBootTest
-public class FunctionalTests {
-
- @Autowired
- private FunctionCatalog catalog;
-
- @Test
- public void words() throws Exception {
- Function<Flux<String>, Flux<String>> function = catalog.lookup(Function.class,
- "function");
- assertThat(function.apply(Flux.just("foo")).blockFirst()).isEqualTo("FOO");
- }
-
-}(The FunctionCatalog always returns functions from Flux to Flux, even if the user declares them with a simpler signature.)
Limitations of Functional Bean Declaration
-Most Spring Cloud Function apps have a relatively small scope compared to the whole of Spring Boot, so we are able to adapt it to these functional bean definitions easily. If you step outside that limited scope, you can extend your Spring Cloud Function app by switching back to @Bean style configuration, or by using a hybrid approach. If you want to take advantage of Spring Boot autoconfiguration for integrations with external datastores, for example, you will need to use @EnableAutoConfiguration. Your functions can still be defined using the functional declarations if you want (i.e. the "hybrid" style), but in that case you will need to explicitly switch off the "full functional mode" using spring.functional.enabled=false so that Spring Boot can take back control.
Dynamic Compilation
-There is a sample app that uses the function compiler to create a
-function from a configuration property. The vanilla "function-sample"
-also has that feature. And there are some scripts that you can run to
-see the compilation happening at run time. To run these examples,
-change into the scripts directory:
cd scripts-
Also, start a RabbitMQ server locally (e.g. execute rabbitmq-server).
Start the Function Registry Service:
-./function-registry.sh-
Register a Function:
-./registerFunction.sh -n uppercase -f "f->f.map(s->s.toString().toUpperCase())"-
Run a REST Microservice using that Function:
-./web.sh -f uppercase -p 9000 -curl -H "Content-Type: text/plain" -H "Accept: text/plain" localhost:9000/uppercase -d foo-
Register a Supplier:
-./registerSupplier.sh -n words -f "()->Flux.just(\"foo\",\"bar\")"-
Run a REST Microservice using that Supplier:
-./web.sh -s words -p 9001 -curl -H "Accept: application/json" localhost:9001/words-
Register a Consumer:
-./registerConsumer.sh -n print -t String -f "System.out::println"-
Run a REST Microservice using that Consumer:
-./web.sh -c print -p 9002 -curl -X POST -H "Content-Type: text/plain" -d foo localhost:9002/print-
Run Stream Processing Microservices:
-First register a streaming words supplier:
-./registerSupplier.sh -n wordstream -f "()->Flux.interval(Duration.ofMillis(1000)).map(i->\"message-\"+i)"-
Then start the source (supplier), processor (function), and sink (consumer) apps -(in reverse order):
-./stream.sh -p 9103 -i uppercaseWords -c print -./stream.sh -p 9102 -i words -f uppercase -o uppercaseWords -./stream.sh -p 9101 -s wordstream -o words-
The output will appear in the console of the sink app (one message per second, converted to uppercase):
-MESSAGE-0 -MESSAGE-1 -MESSAGE-2 -MESSAGE-3 -MESSAGE-4 -MESSAGE-5 -MESSAGE-6 -MESSAGE-7 -MESSAGE-8 -MESSAGE-9 -...-
Serverless Platform Adapters
-As well as being able to run as a standalone process, a Spring Cloud -Function application can be adapted to run one of the existing -serverless platforms. In the project there are adapters for -AWS -Lambda, -Azure, -and -Apache -OpenWhisk. The Oracle Fn platform -has its own Spring Cloud Function adapter. And -Riff supports Java functions and its -Java Function -Invoker acts natively is an adapter for Spring Cloud Function jars.
-3.0.0.BUILD-SNAPSHOT
The OpenWhisk adapter is in the form of an executable jar that can be used in a a docker image to be deployed to Openwhisk. The platform works in request-response mode, listening on port 8080 on a specific endpoint, so the adapter is a simple Spring MVC application.
Spring Cloud Function
@@ -111,7 +118,12 @@ $(addBlockSwitches);3.0.0.BUILD-SNAPSHOT
-
The standard entry point of the API is the Spring configuration annotation @EnableFunctionDeployer. If that is used in a Spring Boot application the deployer kicks in and looks for some configuration to tell it where to find the function jar. At a minimum the user has to provide a function.location which is a URL or resource location for the archive containing the functions. It can optionally use a maven: prefix to locate the artifact via a dependency lookup (see FunctionProperties for complete details). A Spring Boot application is bootstrapped from the jar file, using the MANIFEST.MF to locate a start class, so that a standard Spring Boot fat jar works well, for example. If the target jar can be launched successfully then the result is a function registered in the main application’s FunctionCatalog. The registered function can be applied by code in the main application, even though it was created in an isolated class loader (by deault).
The standard entry point is to add spring-cloud-function-deployer to the classpath, the deployer kicks in and looks for some configuration to tell it where to find the function jar.
<dependency>
+ <groupId>org.springframework.cloud</groupId>
+ <artifactId>spring-cloud-function-deployer</artifactId>
+ <version>${spring.cloud.function.version}</version>
+</dependency>At a minimum the user has to provide a spring.cloud.function.location which is a URL or resource location for the archive containing the functions. It can optionally use a maven: prefix to locate the artifact via a dependency lookup (see FunctionProperties for complete details). A Spring Boot application is bootstrapped from the jar file, using the MANIFEST.MF to locate a start class, so that a standard Spring Boot fat jar works well, for example. If the target jar can be launched successfully then the result is a function registered in the main application’s FunctionCatalog. The registered function can be applied by code in the main application, even though it was created in an isolated class loader (by deault).
Here is the example of deploying a JAR which contains an 'uppercase' function and invoking it .
+@SpringBootApplication
+public class DeployFunctionDemo {
+
+ public static void main(String[] args) {
+ ApplicationContext context = SpringApplication.run(DeployFunctionDemo.class,
+ "--spring.cloud.function.location=..../target/uppercase-0.0.1-SNAPSHOT.jar",
+ "--spring.cloud.function.function-name=uppercase");
+
+ FunctionCatalog catalog = context.getBean(FunctionCatalog.class);
+ Function<String, String> function = catalog.lookup("uppercase");
+ System.out.println(function.apply("hello"));
+ }
+}AWS Lambda
+The AWS adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.
+The adapter has a couple of generic request handlers that you can use. The most generic is SpringBootStreamHandler, which uses a Jackson ObjectMapper provided by Spring Boot to serialize and deserialize the objects in the function. There is also a SpringBootRequestHandler which you can extend, and provide the input and output types as type parameters (enabling AWS to inspect the class and do the JSON conversions itself).
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name (e.g. as FUNCTION_NAME environment variable in AWS). The functions are extracted from the Spring Cloud FunctionCatalog (searching first for Function then Consumer and finally Supplier).
Notes on JAR Layout
+You don’t need the Spring Cloud Function Web or Stream adapter at runtime in Lambda, so you might
+need to exclude those before you create the JAR you send to AWS. A Lambda application has to be
+shaded, but a Spring Boot standalone application does not, so you can run the same app using 2
+separate jars (as per the sample). The sample app creates 2 jar files, one with an aws
+classifier for deploying in Lambda, and one executable (thin) jar that includes spring-cloud-function-web
+at runtime. Spring Cloud Function will try and locate a "main class" for you from the JAR file
+manifest, using the Start-Class attribute (which will be added for you by the Spring Boot
+tooling if you use the starter parent). If there is no Start-Class in your manifest you can
+use an environment variable or system property MAIN_CLASS when you deploy the function to AWS.
If you are not using the functional bean definitions but relying on Spring Boot’s auto-configuration, +then additional transformers must be configured as part of the maven-shade-plugin execution.
+<plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-shade-plugin</artifactId>
+ <dependencies>
+ <dependency>
+ <groupId>org.springframework.boot</groupId>
+ <artifactId>spring-boot-maven-plugin</artifactId>
+ </dependency>
+ </dependencies>
+ <configuration>
+ <createDependencyReducedPom>false</createDependencyReducedPom>
+ <shadedArtifactAttached>true</shadedArtifactAttached>
+ <shadedClassifierName>aws</shadedClassifierName>
+ <transformers>
+ <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
+ <resource>META-INF/spring.handlers</resource>
+ </transformer>
+ <transformer implementation="org.springframework.boot.maven.PropertiesMergingResourceTransformer">
+ <resource>META-INF/spring.factories</resource>
+ </transformer>
+ <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
+ <resource>META-INF/spring.schemas</resource>
+ </transformer>
+ </transformers>
+ </configuration>
+</plugin>Build file setup
+In order to run Spring Cloud Function applications on AWS Lambda, you can leverage Maven or Gradle + plugins offered by the cloud platform provider.
+Maven
+In order to use the adapter plugin for Maven, add the plugin dependency to your pom.xml
+file:
<dependencies>
+ <dependency>
+ <groupId>org.springframework.cloud</groupId>
+ <artifactId>spring-cloud-function-adapter-aws</artifactId>
+ </dependency>
+</dependencies>As pointed out in the Notes on JAR Layout, you wil need a shaded jar in order to upload it +to AWS Lambda. You can use the Maven Shade Plugin for that. +The example of the setup can be found above.
+You can use theSpring Boot Maven Plugin to generate the thin jar.
+<plugin>
+ <groupId>org.springframework.boot</groupId>
+ <artifactId>spring-boot-maven-plugin</artifactId>
+ <dependencies>
+ <dependency>
+ <groupId>org.springframework.boot.experimental</groupId>
+ <artifactId>spring-boot-thin-layout</artifactId>
+ <version>${wrapper.version}</version>
+ </dependency>
+ </dependencies>
+</plugin>You can find the entire sample pom.xml file for deploying Spring Cloud Function
+applications to AWS Lambda with Maven here.
Gradle
+In order to use the adapter plugin for Gradle, add the dependency to your build.gradle file:
dependencies {
+ compile("org.springframework.cloud:spring-cloud-function-adapter-aws:${version}")
+}As pointed out in Notes on JAR Layout, you wil need a shaded jar in order to upload it +to AWS Lambda. You can use the Gradle Shadow Plugin for that:
+buildscript {
+ dependencies {
+ classpath "com.github.jengelman.gradle.plugins:shadow:${shadowPluginVersion}"
+ }
+}
+apply plugin: 'com.github.johnrengelman.shadow'
+
+assemble.dependsOn = [shadowJar]
+
+import com.github.jengelman.gradle.plugins.shadow.transformers.*
+
+shadowJar {
+ classifier = 'aws'
+ dependencies {
+ exclude(
+ dependency("org.springframework.cloud:spring-cloud-function-web:${springCloudFunctionVersion}"))
+ }
+ // Required for Spring
+ mergeServiceFiles()
+ append 'META-INF/spring.handlers'
+ append 'META-INF/spring.schemas'
+ append 'META-INF/spring.tooling'
+ transform(PropertiesFileTransformer) {
+ paths = ['META-INF/spring.factories']
+ mergeStrategy = "append"
+ }
+}You can use the Spring Boot Gradle Plugin and Spring Boot Thin Gradle Plugin to generate +the thin jar.
+buildscript {
+ dependencies {
+ classpath("org.springframework.boot.experimental:spring-boot-thin-gradle-plugin:${wrapperVersion}")
+ classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
+ }
+}
+apply plugin: 'org.springframework.boot'
+apply plugin: 'org.springframework.boot.experimental.thin-launcher'
+assemble.dependsOn = [thinJar]You can find the entire sample build.gradle file for deploying Spring Cloud Function
+applications to AWS Lambda with Gradle here.
Upload
+Build the sample under spring-cloud-function-samples/function-sample-aws and upload the -aws jar file to Lambda. The handler can be example.Handler or org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler (FQN of the class, not a method reference, although Lambda does accept method references).
./mvnw -U clean package+
Using the AWS command line tools it looks like this:
+aws lambda create-function --function-name Uppercase --role arn:aws:iam::[USERID]:role/service-role/[ROLE] --zip-file fileb://function-sample-aws/target/function-sample-aws-2.0.0.BUILD-SNAPSHOT-aws.jar --handler org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler --description "Spring Cloud Function Adapter Example" --runtime java8 --region us-east-1 --timeout 30 --memory-size 1024 --publish+
The input type for the function in the AWS sample is a Foo with a single property called "value". So you would need this to test it:
+{
+ "value": "test"
+}
+| + + | +
+The AWS sample app is written in the "functional" style (as an ApplicationContextInitializer). This is much faster on startup in Lambda than the traditional @Bean style, so if you don’t need @Beans (or @EnableAutoConfiguration) it’s a good choice. Warm starts are not affected.
+ |
+
Type Conversion
+Spring Cloud Function will attempt to transparently handle type conversion between the raw +input stream and types declared by your function.
+For example, if your function signature is as such Function<Foo, Bar> we will attempt to convert
+incoming stream event to an instance of Foo.
In the event type is not known or can not be determined (e.g., Function<?, ?>) we will attempt to
+convert an incoming stream event to a generic Map.
Raw Input
+There are times when you may want to have access to a raw input. In this case all you need is to declare your
+function signature to accept InputStream. For example, Function<InputStream, ?>. In this case
+we will not attempt any conversion and will pass the raw input directly to a function.
Microsoft Azure
+The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
+You can write an app with a single @Bean of type Function and it will be deployable in Azure if you get the JAR file laid out right.
There is an AzureSpringBootRequestHandler which you must extend, and provide the input and output types as annotated method parameters (enabling Azure to inspect the class and create JSON bindings). The base class has two useful methods (handleRequest and handleOutput) to which you can delegate the actual function call, so mostly the function will only ever have one line.
Example:
+public class FooHandler extends AzureSpringBootRequestHandler<Foo, Bar> {
+ @FunctionName("uppercase")
+ public Bar execute(
+ @HttpTrigger(name = "req", methods = { HttpMethod.GET,
+ HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS)
+ Foo foo,
+ ExecutionContext context) {
+ return handleRequest(foo, context);
+ }
+}This Azure handler will delegate to a Function<Foo,Bar> bean (or a Function<Publisher<Foo>,Publisher<Bar>>). Some Azure triggers (e.g. @CosmosDBTrigger) result in a input type of List and in that case you can bind to List in the Azure handler, or String (the raw JSON). The List input delegates to a Function with input type Map<String,Object>, or Publisher or List of the same type. The output of the Function can be a List (one-for-one) or a single value (aggregation), and the output binding in the Azure declaration should match.
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name. Or if you make the @FunctionName in the Azure handler method match the function name it should work that way (also for function apps with multiple functions). The functions are extracted from the Spring Cloud FunctionCatalog so the default function names are the same as the bean names.
Accessing Azure ExecutionContext
+Some time there is a need to access the target execution context provided by Azure runtime in the form of com.microsoft.azure.functions.ExecutionContext.
+For example one of such needs is logging, so it can appear in the Azure console.
For that purpose Spring Cloud Function will register ExecutionContext as bean in the Application context, so it could be injected into your function.
+For example
@Bean
+public Function<Foo, Bar> uppercase(ExecutionContext targetContext) {
+ return foo -> {
+ targetContext.getLogger().info("Invoking 'uppercase' on " + foo.getValue());
+ return new Bar(foo.getValue().toUpperCase());
+ };
+}Normally type-based injection should suffice, however if need to you can also utilise the bean name under which it is registered which is targetExecutionContext.
Notes on JAR Layout
+You don’t need the Spring Cloud Function Web at runtime in Azure, so you can exclude this +before you create the JAR you deploy to Azure, but it won’t be used if you include it, so +it doesn’t hurt to leave it in. A function application on Azure is an archive generated by + the Maven plugin. The function lives in the JAR file generated by this project. + The sample creates it as an executable jar, using the thin layout, so that Azure can find + the handler classes. If you prefer you can just use a regular flat JAR file. + The dependencies should not be included.
+Build file setup
+In order to run Spring Cloud Function applications on Microsoft Azure, you can leverage the Maven +plugin offered by the cloud platform provider.
+In order to use the adapter plugin for Maven, add the plugin dependency to your pom.xml
+file:
<dependencies>
+ <dependency>
+ <groupId>org.springframework.cloud</groupId>
+ <artifactId>spring-cloud-function-adapter-azure</artifactId>
+ </dependency>
+</dependencies>Then, configure the plugin. You will need to provide Azure-specific configuration for your
+application, specifying the resourceGroup, appName and other optional properties, and
+ add the package goal execution so that the function.json file required by Azure is
+ generated for you. Full plugin documentation can be found in the plugin repository.
<plugin>
+ <groupId>com.microsoft.azure</groupId>
+ <artifactId>azure-functions-maven-plugin</artifactId>
+ <configuration>
+ <resourceGroup>${functionResourceGroup}</resourceGroup>
+ <appName>${functionAppName}</appName>
+ </configuration>
+ <executions>
+ <execution>
+ <id>package-functions</id>
+ <goals>
+ <goal>package</goal>
+ </goals>
+ </execution>
+ </executions>
+</plugin>You will also have to ensure that the files to be scanned by the plugin can be found in the +Azure functions staging directory (see the plugin repository + for more details on the staging directory and it’s default location).
+You can find the entire sample pom.xml file for deploying Spring Cloud Function
+applications to Microsoft Azure with Maven here.
| + + | ++As of yet, only Maven plugin is available. Gradle plugin has not been created by +the cloud platform provider. + | +
Build
+./mvnw -U clean package+
Running the sample
+You can run the sample locally, just like the other Spring Cloud Function samples:
++
+
and curl -H "Content-Type: text/plain" localhost:8080/function -d '{"value": "hello foobar"}'.
You will need the az CLI app (see https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-first-java-maven for more detail). To deploy the function on Azure runtime:
$ az login +$ mvn azure-functions:deploy+
On another terminal try this: curl https://<azure-function-url-from-the-log>/api/uppercase -d '{"value": "hello foobar!"}'. Please ensure that you use the right URL for the function above. Alternatively you can test the function in the Azure Dashboard UI (click on the function name, go to the right hand side and click "Test" and to the bottom right, "Run").
The input type for the function in the Azure sample is a Foo with a single property called "value". So you need this to test it with something like below:
+{
+ "value": "foobar"
+}
+| + + | +
+The Azure sample app is written in the "non-functional" style (using @Bean). The functional style (with just Function or ApplicationContextInitializer) is much faster on startup in Azure than the traditional @Bean style, so if you don’t need @Beans (or @EnableAutoConfiguration) it’s a good choice. Warm starts are not affected.
+ |
+