Chapter 5. Using Red Hat OpenShift Dev Spaces for application development

Procedure

1. Create a devfile, named devfile.yaml, at the root of the repository.

2. Add schema and metadata information to the devfile.

   schemaVersion: 2.2.0               

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   metadata:                          

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     name: <workspace-name>           

   3

   
     version: <version>               

   4

   
     displayName: <display-name>      

   5

   1

   The schema version of the devfile.

   2

   Define metadata for your workspace.

   3

   Define a name for your workspace.

   4

   Define the version of the devfile.

   5

   Define the display name to use on a devfile registry.

3. Define variables. You can use the value of the variable throughout the devfile by referencing the variable.

   variables:
     imageRegistry: 'image-registry.openshift-image-registry.svc:5000'       

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     imageName: 'helloworld'        

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     nodeName: 'helloworld'         

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     target-namespace: 'getting-started' 

   4

   1

   Define the registry to which you want to deploy your application image. The example uses the internal OpenShift registry.

   2

   Define a name for the image that will be built for the application.

   3

   Define a name for the node that will contain the application.

   4

   The namespace in which the application is to be deployed.

4. Incorporate tools into the workspace for building your application within the workspace.

   Note

   When running OpenShift Dev Spaces in the developer sandbox, you can only use the predefined namespace. Therefore, you must comment out the following lines inside the env definition:

   - name: TARGET_NAMESPACE
    .value: '{{target-namespace}}'

   components:                       

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     - name: tools
       container:                    

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         image: registry.redhat.io/devspaces/udi-rhel8:3.11-14
         memoryLimit: 1512Mi
         mountSources: true
         volumeMounts:
           - name: m2
             path: /home/user/.m2
         env:                        

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           - name: JAVA_OPTS
             value: '-Djava.security.egd=file:/dev/urandom -Djboss.host.name=localhost'
           - name: DEBUG_PORT
             value: '5005'
           - name: NODE_NAME
             value: '{{nodeName}}'
           - name: IMAGE_REGISTRY
             value: '{{imageRegistry}}'
           - name: IMAGE
             value: '{{imageName}}'
           - name: TARGET_NAMESPACE
            .value: '{{target-namespace}}'
           - name: VSCODE_DEFAULT_WORKSPACE
             value: /projects/wildfly-devfile-examples/.code-workspace
           - name: USE_JAVA17
             value: 'true'
         endpoints:                  

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           - name: debug
             exposure: internal
             protocol: tcp
             targetPort: 5005
           - name: 'http'
             protocol: http
             targetPort: 8080
             exposure: public
           - name: 'management'
             targetPort: 9990
             protocol: http
             exposure: internal
           - name: 'transactions'
             targetPort: 4172
             protocol: tcp
             exposure: internal
     - name: m2                     

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       volume:
         size: 3Gi

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   Define a component named tools of the type container.

   2

   Use the udi-rhel8:3.11-14 UDI container from the registry.redhat.io/devspaces registry with the specified configuration.

   3

   Define environment variables.

   4

   Define the container endpoints as follows:

   • exposure: Define how the endpoint should be exposed on the network.
   • protocol: Define the application and transport protocols of the traffic that will go through this endpoint.
   • targetPort: The port number to be used within the container component. The same port cannot be used by two different container components.

   5

   Define a volume component. This is used in the tools component to mount the Maven repository.

5. Add innerloop and outerloop commands.

   commands:
     - id: package            

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       exec:
         label: "InnerLoop 01 - Build the application"
         component: tools
         commandLine: mvn clean package -Popenshift -Dmaven.wagon.http.ssl.insecure=true
         workingDir: ${PROJECT_SOURCE}/helloworld
         group:
           kind: build
           isDefault: true
     - id: run                

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       exec:
         label: "InnerLoop 02 - Run the application in dev mode"
         component: tools
         commandLine: ./target/server/bin/standalone.sh -Djboss.host.name=${NODE_NAME}
         workingDir: ${PROJECT_SOURCE}/helloworld
         group:
           kind: run
           isDefault: true
     - id: debug              

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       exec:
         label: "InnerLoop 03 - Debug the application in dev mode"
         component: tools
         commandLine: ./target/server/bin/standalone.sh -Djboss.host.name=${NODE_NAME} --debug
         workingDir: ${PROJECT_SOURCE}/helloworld
         group:
           kind: debug
           isDefault: true
     - id: shutdown           

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       exec:
         label: "InnerLoop 04 - Shutdown the server"
         component: tools
         commandLine: ./target/server/bin/jboss-cli.sh -c --command=shutdown
         workingDir: ${PROJECT_SOURCE}/helloworld
         hotReloadCapable: false
         group:
           kind: run
           isDefault: false
     - id: deploy-image       

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       exec:
         label: "OuterLoop 01 - Deploy Image to OpenShift"
         component: tools
         workingDir: ${PROJECT_SOURCE}/helloworld
         # When using developer sandbox, prefix the following command with export "IMAGE_REGISTRY_NAMESPACE=$(oc project -q) &&" because you can only use the predefined namespace in the developer sandbox
         commandLine: "helm repo add jboss https://jbossas.github.io/eap-charts/ && helm install ${IMAGE} --namespace=${IMAGE_REGISTRY_NAMESPACE} -f ./charts/helm.yaml jboss/eap8"
         group:
           kind: run
           isDefault: false
     - id: undeploy-image     

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       exec:
         label: "OuterLoop 02 - Undeploy Image from OpenShift"
         component: tools
         workingDir: ${PROJECT_SOURCE}/helloworld
         commandLine: "helm uninstall ${IMAGE}"
         group:
           kind: run
           isDefault: false

   1

   Define a command to build the application. This executes mvn clean package -Popenshift -Dmaven.wagon.http.ssl.insecure=true in the workspace to provision a server with the application deployed to the server.

   2

   Define a command to run the application. This executes ./target/server/bin/standalone.sh -Djboss.host.name=${NODE_NAME} to start the provisioned server within the workspace.

   3

   Define a command to debug the application. This starts the server with the --debug option.

   4

   Define a command to shut down the running server.

   5

   Define a command to deploy the application to OpenShift Container Platform with helm.

   6

   Define a command to undeploy the application from OpenShift Container Platform with helm.

6. Optionally, configure Visual Studio Code.

   1. Create a directory .vscode for Visual Studio Code configuration.

   2. Navigate to the .vscode directory.

      $ cd .vscode

   3. Create a file extensions.json to configure the extensions to be installed in Visual Studio Code.

      Note

      You might need to configure a registry to install the extensions. For more information, see Managing IDE extensions in the OpenShift Dev Spaces Administration guide guide.

      {
        // See https://go.microsoft.com/fwlink/?LinkId=827846
        // for the documentation about the extensions.json format
        "recommendations": [
          "redhat.java",
          "vscjava.vscode-java-debug",
          "vscjava.vscode-java-test",
          "redhat.fabric8-analytics",
          "cnshenj.vscode-task-manager" 

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        ]
      }

      1

      Task manager extension. Provides a custom activity view for the commands in the devfile.

   4. Create a file launch.json to configure a debug session in Visual Studio Code.

      {
        "version": "0.2.0",
        "configurations": [
          {
            "type": "java",
            "name": "Attach to running server",
            "request": "attach",
            "hostName": "localhost",
            "port": 5005
          }
        ]
      }

7. Create a file settings.json.

   {
     "java.server.launchMode": "Standard",
     "editor.codeActionsOnSave": {
     }
   }

8. Push the changes to your repository.

Procedure

1. To run the application, use the InnerLoop 02 - Run the application in dev mode command .

   • If you have installed the optional task manager Visual Studio Code extension:

     1. On the Activity Bar, click the Task Manager icon. The list of commands you defined in the devfile are displayed.
     2. Select InnerLoop 02 - Run the application in dev mode and click the Run Task icon that is displayed.

   • Otherwise:

     1. Press the F1 key.
     2. In the search field that is displayed, enter "run task".
     3. From the results, select Tasks: Run task.
     4. In the search field, enter "devfile".
     5. From the results, select InnerLoop 02 - Run the application in dev mode.

2. In the pop-up window that is displayed with the following message, click no:

   A new process is now listening on port 4712 but is listening on interface ::ffff:7f00:1 which is internal. You should change to be remotely available. Would you want to add a redirect for this port so it becomes available ?

3. In the pop-up window that is displayed with the following message, click Open In New Tab:

   Process http is now listening on port 8080. Open it ?

Procedure

1. To add a breakpoint, click in the left margin of the editor, next to the required line of code. A red dot is displayed in the margin to mark the breakpoint you added.

2. To debug the application, use the InnerLoop 03 - InnerLoop 03 - Debug the application in dev mode command .

   • If you have installed the optional task manager Visual Studio Code extension:

     1. On the Activity Bar, click the Task Manager icon. The list of commands you defined in the devfile are displayed.
     2. Select InnerLoop 03 - InnerLoop 03 - Debug the application in dev mode and click the Run Task icon that is displayed.

   • Otherwise:

     1. Press the F1 key.
     2. In the search field that is displayed, enter "run task".
     3. From the results, select Tasks: Run task.
     4. In the search field, enter "devfile".
     5. From the results, select InnerLoop 03 - Debug the application in dev mode .

Verification

1. Obtain the application URL.

   $ oc get route helloworld

2. Navigate to the URL.

   You get the following output:

   Hello World!