README.md

Exercise 2 - Build a simple Spring Boot microservice

In this section, we'll build a simple Spring boot microservice and deploy it to Azure Spring Apps. This will give us a starting point for adding Spring Apps technologies in later sections.

Task 1 : Create a simple Spring Boot microservice

💡 Note: All subsequent commands in this workshop should be run from the same directory, except where otherwise indicated via cd commands.

1. In an empty directory in git bash execute the curl command line mentioned below:

curl https://start.spring.io/starter.tgz -d type=maven-project -d dependencies=web -d baseDir=simple-microservice -d bootVersion=2.7.5 -d javaVersion=17 | tar -xzvf -

**Info :**We force the Spring Boot version to be 2.7.5, and keep default settings that use the com.example.demo package.

Task 2 : Add a new Spring MVC Controller

1. Now minimize the Git Bash window and navigate to the path C:\Users\demouser\simple-microservice\src\main\java\com\example\demo in File Explorer.

   

2. Open a new notepad, and paste the below code :

   package com.example.demo;
   
   import org.springframework.web.bind.annotation.GetMapping;
   import org.springframework.web.bind.annotation.RestController;
   
   @RestController
   public class HelloController {
   
       @GetMapping("/hello")
       public String hello() {
           return "Hello from Azure Spring Apps\n";
       }
   }

3. Save the file next to DemoApplication.java in the C:\Users\demouser\simple-microservice\src\main\java\com\example\demo as HelloController.java by changing the save as type to all files and then save as shown below.

   

Task 3 : Test the project locally

1. Now navigate back to Git Bash and run the project:

   cd simple-microservice
   ./mvnw spring-boot:run &
   cd ..

   Note: When the control is stuck during the deployment process, you can press enter to make the process run in background and proceed to the next steps to access the endpoint. This is because the control will be checking for the available port to host the endpoint.

   Note: In some cases, you may face an issue that the project builds failure due to Port already in use , then you can terminate the process which is running in the port by running the below given commands in Command Prompt. After terminating the process, you need to re-run the Step-1 commands of Task-3 in Git Bash.

   netstat  -ano  |  findstr  < Enter Port Number > 
   taskkill  /F  /PID  < Enter Process Id >

2. Run the curl command for requesting the /hello endpoint where it should return the "Hello from Azure Spring Apps" as the message.

   curl http://127.0.0.1:8080/hello

   

3. Finally, kill running app by using the below mentioned command.

   kill %1

Note: If the command indicates a BUILD FAILURE error, you can Ignore it and continue with the next task as the expected output is observed in Step-2.

Task 4 : Create and deploy the application on Azure Spring Apps

This section shows how to create an app instance and then deploy your code to it.

1. In order to create the app instance graphically, you can navigate back to the Azure portal and look for your Azure Spring Apps instance in your resource group.

   

2. Click on the Apps under Settings on the navigation sidebar.

   

3. Click on the + Create App link at the top of the Apps page.

   

4. On Create App page, follow the below details:

   • App Name: Enter simple-microservice (1)

   • Deployment Type: Choose Artifacts(Java/.Net core) (2) from the drop-down

   • Runtime Platform: Choose Java 17 (3) from the drop-down

   • Click on Create (4)

     

   💡 Note: Alternatively, you can use the command line to create the app instance, which is easier. If you performed till step 4, skip this Note and continue with Step 5.

   Note: Replace the DID with the value, you can also find it from the Environment details page and run the below given command in Git Bash

   az spring app create -n simple-microservice -g spring-apps-workshop-DID -s azure-spring-apps-lab-DID --runtime-version Java_17

5. Now you can build your simple-microservice project and deploy it to Azure Spring Apps by running the below command.

   Note: Replace the DID with the value, you can also find it from the Environment details page and run the below given command in Git Bash

   cd simple-microservice
   ./mvnw clean package
   az spring app deploy -n simple-microservice -g spring-apps-workshop-DID -s azure-spring-apps-lab-DID --artifact-path target/demo-0.0.1-SNAPSHOT.jar
   cd ..

6. This creates a jar file on your local disk and uploads it to the app instance you created in the preceding step. The az command will output a result in JSON. You don't need to pay attention to this output right now, but in the future, you will find it useful for diagnostic and testing purposes.

Task 5 : Test the project in the cloud

1. Navigate back to Azure Portal, From the resource group spring-apps-workshop- select the Azure Spring Apps instance named azure-spring-apps-lab-.

   

2. Click Apps in the Settings section of the navigation pane and select simple-microservice

3. From the Overview tab, mouse over the URL labeled as Test Endpoint and click the clipboard icon that appears.

   

4. You can now use CURL again to test the /hello endpoint in GitBash, this time served by Azure Spring Apps. For example.

   curl https://primary:...simple-microservice/default/hello/

5. Append hello/ at the end of the URL. Failure to do this will result in a "404 not found".

6. If successful, you should see the message: Hello from Azure Spring Apps.

   

Conclusion

Congratulations, you have deployed your first Spring Boot microservice to Azure Spring Apps! If you need to check your code, the final project is available in the "simple-microservice" folder. Here is the final script to build and deploy everything that was done in this guide:

curl https://start.spring.io/starter.tgz -d type=maven-project -d dependencies=web -d baseDir=simple-microservice -d bootVersion=2.7.5 -d javaVersion=17 | tar -xzvf -
cd simple-microservice
cat > HelloController.java << EOF
package com.example.demo;