Integration with AWS Secrets Manager (#1638)

EnvironmentRepository for AWS Secrets Manager

Co-authored-by: Tejas Pandilwar <tejas.pandilwar@gs.com>
Co-authored-by: Spencer Gibb <sgibb@pivotal.io>

docs/src/main/asciidoc/spring-cloud-config.adoc

@@ -802,6 +802,38 @@ credhub set --name "/my-app/default/master/more-shared" --type=json
 value: {"shared.word1": "hello", "shared.word2": "world"}
 ----
 
+==== AWS Secrets Manager
+When using AWS Secrets Manager as a backend, you can share configuration with all applications by placing configuration in `/application/` or by placing it in the `default` profile for the application.
+For example, if you add secrets with the following keys, all application using the config server will have the properties `shared.foo` and `shared.bar` available to them:
+
+[source]
+----
+secret name = /secret/application-default/
+----
+[source,json]
+----
+secret value =
+{
+ shared.foo: foo,
+ shared.bar: bar
+}
+----
+or
+[source]
+----
+secret name = /secret/application/
+----
+[source,json]
+----
+secret value =
+{
+ shared.foo: foo,
+ shared.bar: bar
+}
+----
+
+----
+
 ==== JDBC Backend
 
 Spring Cloud Config Server supports JDBC (relational database) as a backend for configuration properties.
@@ -900,6 +932,46 @@ Configuration files are stored in your bucket as `{application}-{profile}.proper
 
 NOTE: When no profile is specified `default` will be used.
 
+==== AWS Secrets Manager Backend
+
+Spring Cloud Config Server supports link:https://aws.amazon.com/secrets-manager/[AWS Secrets Manager] as a backend for configuration properties.
+You can enable this feature by adding a dependency to link:https://github.com/aws/aws-sdk-java/tree/master/aws-java-sdk-secretsmanager[AWS Java SDK for Secrets Manager].
+
+[source,xml,indent=0]
+.pom.xml
+----
+<dependency>
+    <groupId>com.amazonaws</groupId>
+    <artifactId>aws-java-sdk-secretsmanager</artifactId>
+</dependency>
+----
+
+The following configuration uses the AWS Secrets Manager client to access secrets.
+
+[source,yaml]
+----
+spring:
+  profiles:
+  	active: awssecretsmanager
+  cloud:
+    config:
+      server:
+        aws-secretsmanager:
+          region: us-east-1
+          endpoint: https://us-east-1.console.aws.amazon.com/
+          origin: aws:secrets:
+          prefix: /secret/foo
+          profileSeparator: _
+
+----
+
+AWS Secrets Manager API credentials are determined using link:https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/credentials.html#credentials-default[Default Credential Provider Chain].
+
+[NOTE]
+====
+- When no application is specified `application` is the default, and when no profile is specified `default` is used.
+====
+
 ==== CredHub Backend
 
 Spring Cloud Config Server supports link:https://docs.cloudfoundry.org/credhub[CredHub] as a backend for configuration properties.