Spring Cloud Config Server with GitHub

Configuring a Spring Cloud Config Server to read configuration from a GitHub repository, using @RefreshScope to refresh beans dynamically, and leveraging Spring Boot Actuator for monitoring and refreshing can be a powerful combination. Let’s go through a step-by-step tutorial.

Step 1: Setup GitHub Repository for Configuration

1. Create a GitHub Repository:

• Create a new GitHub repository to store your configuration files. Let’s call it config-repo.

1. Add Configuration Files:

• Add application configuration files (e.g., application.yml, application.properties) to the config-repo. These files will contain the properties for your services.

Step 2: Create Spring Cloud Config Server

1. Create a new Spring Boot Project:

• Use Spring Initializr to create a new Spring Boot project.
• Add dependencies: Config Server, Actuator, and Web.

1. Configure application.properties (or application.yml):

   spring.application.name=config-server
   server.port=8888
   spring.cloud.config.server.git.uri=https://github.com/your-username/config-repo.git

3. Enable Config Server:

• Annotate the main application class with @EnableConfigServer.

4. Run the Config Server:

• Start the Config Server. It will fetch configuration from the GitHub repository.

Step 3: Create a Sample Service

1. Create a new Spring Boot Project:

• Use Spring Initializr to create a new Spring Boot project.
• Add dependencies: Web, Actuator, and Config Client.

1. Configure bootstrap.properties (or bootstrap.yml):

   spring.application.name=sample-service
   server.port=8080
   spring.cloud.config.uri=http://localhost:8888

3. Create a Sample Controller:

• Create a simple REST controller with a property injected using @Value.

Step 4: Add @RefreshScope

1. Update the Controller:

• Add @RefreshScope annotation to the controller to enable dynamic refresh.

Step 5: Enable Actuator Endpoints

1. Configure Actuator in application.properties (or application.yml):

   management.endpoints.web.exposure.include=*

2. Refresh Endpoint:

• The actuator/refresh endpoint can be used to trigger a refresh.

Step 6: Test the Application

1. Run the Sample Service:

• Start the Sample Service.

1. Access the Sample Endpoint:

• Visit http://localhost:8080/sample to see the initial configuration.

1. Update Configuration in GitHub:

• Make changes to the configuration files in the GitHub repository.

1. Trigger Refresh:

• Hit the actuator/refresh endpoint of the Sample Service: POST http://localhost:8080/actuator/refresh.

1. Access the Sample Endpoint Again:

• Visit http://localhost:8080/sample to see the updated configuration.

Congratulations! You’ve successfully set up a Spring Cloud Config Server reading configuration from a GitHub repository, used @RefreshScope to dynamically refresh beans, and enabled Actuator for monitoring and refreshing.