Enable Spring Native apps for Application Live View

This topic for developers tells you how to configure a Spring Native app to be observed by Application Live View within Tanzu Application Platform (commonly known as TAP).

Configure a Spring Native application

To make Application Live View interact with a Spring Native app within Tanzu Application Platform:

1. Add the spring-boot-starter-actuator module dependency for Maven in pom.xml as follows:

   <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
   </dependency>
   

2. Add a native profile that includes the native-maven-plugin for the build phase in pom.xml, as follows:

   <profiles>
    <profile>
        <id>native</id>
        <build>
          <plugins>
              <plugin>
                <groupId>org.graalvm.buildtools</groupId>
                  <artifactId>native-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    </profile>
   </profiles>
   

   Important

   For Maven-based projects, you must add the org.graalvm.buildtools build plug-in and configure it to run when the native profile is active.

3. Add the following configuration in pom.xml to generate build-info.properties in your Spring Boot application. Application Live View uses this information to display the Spring Boot version that the app uses.

   <plugin>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-maven-plugin</artifactId>
   <executions>
    <execution>
      <goals>
        <goal>build-info</goal>
      </goals>
      <configuration>
        <additionalProperties>
          <spring.boot.version>${project.parent.version}</spring.boot.version>
        </additionalProperties>
      </configuration>
    </execution>
   </executions>
   </plugin>
   

Create a native workload

Create a workload for the Spring Native application similar to the following example:

$ tanzu apps workload create spring-cloud-serverless \
--git-repo https://github.com/vudayani-vmw/spring-cloud-serverless --git-branch main \
--type web --label apps.tanzu.vmware.com/auto-configure-actuators=true \
--label app.kubernetes.io/part-of=spring-cloud-serverless --yes \
--annotation autoscaling.knative.dev/min-scale=1 \
--build-env "BP_JVM_VERSION=17" --build-env "BP_NATIVE_IMAGE=true" \
--build-env "BP_MAVEN_BUILD_ARGUMENTS= -Pnative -Dmaven.test.skip=true \
--no-transfer-progress package \
-Dspring-boot.aot.jvmArguments='-Dmanagement.endpoint.health.probes.add-additional-paths='true' \
-Dmanagement.endpoint.health.show-details='always' \
-Dmanagement.endpoints.web.base-path='/actuator' \
-Dmanagement.endpoints.web.exposure.include='*' \
-Dmanagement.health.probes.enabled='true' \
-Dmanagement.server.port=8081 -Dserver.port=8080' "

Where:

• The required build arguments, such as BP_JVM_VERSION, BP_NATIVE_IMAGE, and BP_MAVEN_BUILD_ARGUMENTS, are configured to build a native executable file as shown in the example. The build environment variables are required to enable a native build profile and native image-building.

• The override configuration options at runtime provide AOT (Ahead-Of-Time) configuration to the build process by using the spring-boot.aot.jvmArguments option. For Gradle builds, the spring-boot.aot.jvmArguments is set as part of the BP_GRADLE_ADDITIONAL_BUILD_ARGUMENTS build environment variable.

These build environment parameters do not directly set the runtime values. The build environment parameters, provided as part of spring-boot.aot.jvmArguments, are only used as build-time signals. These signals indicate to generate code that allows configuration options to be set at runtime.

Configure at runtime

There are two methods to override the configuration at runtime. You can, by default, let Spring Boot conventions configure automatically, or you can use environment variables to configure manually.

Configure automatically (default)

Automatic configuration by Spring Boot conventions is the default method. Spring Boot conventions add the necessary environment variables and labels to the workload PodSpec based on the apps.tanzu.vmware.com/auto-configure-actuators flag. When the apps.tanzu.vmware.com/auto-configure-actuators is set to true, Spring Boot conventions adds the following environment variables to the native workload PodSpec:

Spec:
  Containers:
    Env:
      Name:   MANAGEMENT_SERVER_PORT
      Value:  8081
      Name:   MANAGEMENT_ENDPOINT_HEALTH_PROBES_ADD_ADDITIONAL_PATHS
      Value:  true
      Name:   MANAGEMENT_ENDPOINT_HEALTH_SHOW_DETAILS
      Value:  always
      Name:   MANAGEMENT_ENDPOINTS_WEB_BASE_PATH
      Value:  /actuator
      Name:   MANAGEMENT_ENDPOINTS_WEB_EXPOSURE_INCLUDE
      Value:  *
      Name:   MANAGEMENT_HEALTH_PROBES_ENABLED
      Value:  true
      Name:   SERVER_PORT
      Value:  8080
      Name:   SERVER_SHUTDOWN_GRACE_PERIOD
      Value:  24s

Configure manually

You can manually override runtime configuration settings by providing environment variables. To customize the configuration, set the relevant environment variables in accordance with your requirements. The following example overrides MANAGEMENT_SERVER_PORT as 8088, and it overrides SERVER_PORT as 8082.

tanzu apps workload create spring-cloud-serverless \
--git-repo https://github.com/vudayani-vmw/spring-cloud-serverless --git-branch main --type web \
--label tanzu.app.live.view.application.flavours=spring-boot_spring-native \
--label apps.tanzu.vmware.com/auto-configure-actuators=true --label \
app.kubernetes.io/part-of=spring-cloud-serverless --label apps.tanzu.vmware.com/has-tests=true \
--yes --annotation autoscaling.knative.dev/min-scale=1 --build-env "BP_JVM_VERSION=17" \
--build-env "BP_NATIVE_IMAGE=true" --build-env "BP_MAVEN_BUILD_ARGUMENTS= -Pnative \
-Dmaven.test.skip=true --no-transfer-progress package \
-Dspring-boot.aot.jvmArguments='-Dmanagement.endpoint.health.probes.add-additional-paths='true' \
-Dmanagement.endpoint.health.show-details='always' -Dmanagement.endpoints.web.base-path='/actuator' \
-Dmanagement.endpoints.web.exposure.include='*' -Dmanagement.health.probes.enabled='true' \
-Dmanagement.server.port=8081 -Dserver.port=8080' " --env MANAGEMENT_SERVER_PORT=8088 \
--env SERVER_PORT=8082

The resulting PodSpec is:

Spec:
  Containers:
    Env:
      Name:   MANAGEMENT_SERVER_PORT
      Value:  8088
      Name:   SERVER_PORT
      Value:  8082
      Name:   MANAGEMENT_ENDPOINT_HEALTH_PROBES_ADD_ADDITIONAL_PATHS
      Value:  true
      Name:   MANAGEMENT_ENDPOINT_HEALTH_SHOW_DETAILS
      Value:  always
      Name:   MANAGEMENT_ENDPOINTS_WEB_BASE_PATH
      Value:  /actuator
      Name:   MANAGEMENT_ENDPOINTS_WEB_EXPOSURE_INCLUDE
      Value:  *
      Name:   MANAGEMENT_HEALTH_PROBES_ENABLED
      Value:  true
      Name:   SERVER_SHUTDOWN_GRACE_PERIOD
      Value:  24s

Spring Boot conventions also set the Application Live View labels on the PodSpec to enable Application Live View.

Verify the applied labels and annotations

Verify the applied labels and annotations by running:

kubectl get podintents.conventions.carto.run WORKLOAD-NAME -o yaml

Where WORKLOAD-NAME is the name of the deployed workload. For example, spring-cloud-serverless.

Expected output of the Spring Boot workload:

...
Labels:       app.kubernetes.io/component=intent
              app.kubernetes.io/part-of=spring-cloud-serverless
              apps.tanzu.vmware.com/auto-configure-actuators=true
              apps.tanzu.vmware.com/has-tests=true
              apps.tanzu.vmware.com/workload-type=web
              carto.run/cluster-template-name=convention-template
              carto.run/resource-name=config-provider
              carto.run/supply-chain-name=source-to-url
              carto.run/template-kind=ClusterConfigTemplate
              carto.run/template-lifecycle=mutable
              carto.run/workload-name=spring-cloud-serverless
              carto.run/workload-namespace=default
              tanzu.app.live.view.application.flavours=spring-boot_spring-native
...