Add resource manager usage for sample readme

eventhubs/spring-cloud-azure-starter/spring-cloud-azure-sample-eventhubs-kafka/README.md

@@ -74,9 +74,6 @@ terraform -chdir=./terraform apply -auto-approve
 
 ```
 
-
-
-
 It may take a few minutes to run the script. After successful running, you will see prompt information like below:
 
 ```shell
@@ -107,7 +104,7 @@ You can go to [Azure portal](https://ms.portal.azure.com/) in your web browser t
 Running the command below to export environment values:
 
 ```shell
- source ./terraform/setup_env.sh
+source ./terraform/setup_env.sh
 ```
 
 ## Run Locally
@@ -145,6 +142,41 @@ To destroy the resources you created.
 terraform -chdir=./terraform destroy -auto-approve
 ```
 
+### Use Azure Resource Manager to retrieve connection string
+
+If you don't want to configure connection string in your application, it's also possible to use Azure Resource Manager to retrieve the connection string. Just make sure the principal have sufficient permission to read resource metadata.
+
+1. After [Provision the Resources](#provision-the-resources) step, active the [application-rm.yaml][application-rm.yaml] profile file.
+
+    ```yaml
+    spring:
+      cloud:
+        azure:
+          profile:
+            subscription-id: ${AZURE_SUBSCRIPTION_ID}
+          eventhubs:
+            namespace: ${AZURE_EVENTHUBS_NAMESPACE}
+            resource:
+              resource-group: ${AZURE_EVENTHUBS_RESOURCE_GROUP}
+        stream:
+          function:
+            definition: consume;supply
+          bindings:
+            consume-in-0:
+              destination: ${EVENTHUBS_KAFKA}
+              group: $Default
+            supply-out-0:
+              destination: ${EVENTHUBS_KAFKA}
+    ```
+2. Add the Azure Resource Manager dependency
+```xml
+<dependency>
+  <groupId>com.azure.spring</groupId>
+  <artifactId>spring-cloud-azure-resourcemanager</artifactId>
+</dependency>
+```
+3. Repeat steps [Run Locally](#run-locally) with the command `mvn clean spring-boot:run -Dspring-boot.run.profiles=rm` and [Verify This Sample](#verify-this-sample).
+
 ## Troubleshooting
 
 - Meet with  `Creating topics with default partitions/replication factor are only supported in CreateTopicRequest version 4+` error.
@@ -156,5 +188,4 @@ terraform -chdir=./terraform destroy -auto-approve
 
   When this error is found, add this configuration item `spring.cloud.stream.kafka.binder.replicationFactor`, with the value set to at least 1. For more information, see [Spring Cloud Stream Kafka Binder Reference Guide](https://docs.spring.io/spring-cloud-stream-binder-kafka/docs/current/reference/html/spring-cloud-stream-binder-kafka.html).
 
-
-
+- [application-rm.yaml]: https://github.com/Azure-Samples/azure-spring-boot-samples/tree/spring-cloud-azure_4.0.0-beta.4/eventhubs/spring-cloud-azure-starter/spring-cloud-azure-sample-eventhubs-kafka/src/main/resources/application-rm.yaml

eventhubs/spring-cloud-azure-starter/spring-cloud-azure-sample-eventhubs-kafka/src/main/resources/application-rm.yaml

@@ -0,0 +1,18 @@
+spring:
+  cloud:
+    azure:
+      profile:
+        subscription-id: ${AZURE_SUBSCRIPTION_ID}
+      eventhubs:
+        namespace: ${AZURE_EVENTHUBS_NAMESPACE}
+        resource:
+          resource-group: ${AZURE_EVENTHUBS_RESOURCE_GROUP}
+    stream:
+      function:
+        definition: consume;supply
+      bindings:
+        consume-in-0:
+          destination: ${EVENTHUBS_KAFKA}
+          group: $Default
+        supply-out-0:
+          destination: ${EVENTHUBS_KAFKA}

eventhubs/spring-cloud-azure-starter/spring-cloud-azure-sample-eventhubs-kafka/terraform/main.tf

@@ -34,6 +34,8 @@ resource "azurerm_resource_group" "main" {
 }
 
 # =================== eventhubs ================
+data "azurerm_subscription" "current" { }
+
 resource "azurecaf_name" "azurecaf_name_eventhubs" {
   name          = var.application_name
   resource_type = "azurerm_eventhub_namespace"

eventhubs/spring-cloud-azure-starter/spring-cloud-azure-sample-eventhubs-kafka/terraform/outputs.tf

@@ -14,7 +14,12 @@ output "EVENTHUBS_KAFKA" {
   description = "The name of created event hubs."
 }
 
-output "RESOURCE_GROUP_NAME" {
+output "AZURE_EVENTHUBS_RESOURCE_GROUP" {
   value = azurerm_resource_group.main.name
-  description = "The resource group name."
+  description = "The Event Hubs resource group name."
+}
+
+output "AZURE_SUBSCRIPTION_ID" {
+  value       = data.azurerm_subscription.current.subscription_id
+  description = "The subscription ID of the resource."
 }

eventhubs/spring-cloud-azure-starter/spring-cloud-azure-sample-eventhubs-kafka/terraform/setup_env.sh

@@ -1,2 +1,5 @@
 export AZURE_EVENTHUBS_CONNECTION_STRING=$(terraform -chdir=./terraform output -raw AZURE_EVENTHUBS_CONNECTION_STRING)
-export EVENTHUBS_KAFKA=$(terraform -chdir=./terraform output -raw EVENTHUBS_KAFKA)
+export EVENTHUBS_KAFKA=$(terraform -chdir=./terraform output -raw EVENTHUBS_KAFKA)
+export AZURE_SUBSCRIPTION_ID=$(terraform -chdir=./terraform output -raw AZURE_SUBSCRIPTION_ID)
+export AZURE_EVENTHUBS_RESOURCE_GROUP=$(terraform -chdir=./terraform output -raw AZURE_EVENTHUBS_RESOURCE_GROUP)
+export AZURE_EVENTHUBS_NAMESPACE=$(terraform -chdir=./terraform output -raw AZURE_EVENTHUBS_NAMESPACE)