PatchExamples.java

package io.fabric8;

import io.fabric8.kubernetes.api.model.Container;
import io.fabric8.kubernetes.api.model.ContainerBuilder;
import io.fabric8.kubernetes.api.model.apps.Deployment;
import io.fabric8.kubernetes.api.model.apps.DeploymentBuilder;
import io.fabric8.kubernetes.client.KubernetesClientBuilder;
import io.fabric8.kubernetes.client.KubernetesClient;
import io.fabric8.kubernetes.client.KubernetesClientException;
import io.fabric8.kubernetes.client.dsl.base.PatchContext;
import io.fabric8.kubernetes.client.dsl.base.PatchType;

import java.util.Collections;
import java.util.List;

public class PatchExamples {
  public static void main(String[] args) {
    try (KubernetesClient kubernetesClient = new KubernetesClientBuilder().build()) {
      Deployment deployment = createNewDeployment("patch-demo", 2);

      deployment = kubernetesClient.apps().deployments()
          .inNamespace("default")
          .resource(deployment)
          .create();

      standardPatchTyped(kubernetesClient, deployment);
      patchStrategicMerge(kubernetesClient, deployment);
      patchStrategicMergeExplicit(kubernetesClient, deployment);
      patchJson(kubernetesClient, deployment);
      patchJsonMerge(kubernetesClient, deployment);
    } catch (KubernetesClientException e) {
      System.out.println("Exception received: " + e.getMessage());
    }
  }

  private static void patchStrategicMergeExplicit(KubernetesClient kubernetesClient, Deployment deployment) {
    kubernetesClient.apps().deployments()
        .inNamespace(deployment.getMetadata().getNamespace())
        .withName(deployment.getMetadata().getName())
        .patch(
            PatchContext.of(PatchType.STRATEGIC_MERGE),
            "{\"spec\":{\"template\":{\"spec\":{\"containers\":[{\"name\":\"patch-demo-ctr-2\",\"image\":\"redis\"}]}}}}");
  }

  private static void standardPatchTyped(KubernetesClient kubernetesClient, Deployment deployment) {
    // Prepare modified patch object
    List<Container> containerList = deployment.getSpec().getTemplate().getSpec().getContainers();
    containerList.add(new ContainerBuilder()
        .withName("patch-demo-ctr-2")
        .withImage("redis")
        .build());
    deployment.getSpec().getTemplate().getSpec().setContainers(containerList);

    // Patch to API Server
    kubernetesClient.apps().deployments()
        .inNamespace(deployment.getMetadata().getNamespace())
        .resource(deployment)
        .patch();
  }

  private static void patchJsonMerge(KubernetesClient kubernetesClient, Deployment deployment) {
    kubernetesClient.apps().deployments()
        .inNamespace(deployment.getMetadata().getNamespace())
        .withName(deployment.getMetadata().getName())
        .patch(PatchContext.of(PatchType.JSON_MERGE), "{\"metadata\":{\"annotations\":{\"foo\":null}}}");
  }

  private static void patchJson(KubernetesClient kubernetesClient, Deployment deployment) {
    kubernetesClient.apps().deployments()
        .inNamespace(deployment.getMetadata().getNamespace())
        .withName(deployment.getMetadata().getName())
        .patch(
            PatchContext.of(PatchType.JSON),
            "[{\"op\": \"test\", \"path\":\"/metadata/labels\", \"value\":null}]");
  }

  private static void patchStrategicMerge(KubernetesClient kubernetesClient, Deployment deployment) {
    kubernetesClient.apps().deployments()
        .inNamespace(deployment.getMetadata().getNamespace())
        .withName(deployment.getMetadata().getName())
        .patch("{\"spec\":{\"template\":{\"spec\":{\"containers\":[{\"name\":\"patch-demo-ctr-2\",\"image\":\"redis\"}]}}}}");
  }

  private static Deployment createNewDeployment(String name, int replicas) {
    return new DeploymentBuilder()
        .withNewMetadata()
        .withName(name)
        .addToAnnotations("foo", "bar")
        .addToAnnotations("app", "nginx")
        .endMetadata()
        .withNewSpec()
        .withReplicas(replicas)
        .withNewSelector()
        .addToMatchLabels(Collections.singletonMap("app", "nginx"))
        .endSelector()
        .withNewTemplate()
        .withNewMetadata()
        .addToLabels("app", "nginx")
        .endMetadata()
        .withNewSpec()
        .addNewContainer()
        .withName("patch-demo-ctr")
        .withImage("nginx")
        .endContainer()
        .endSpec()
        .endTemplate()
        .endSpec()
        .build();
  }
}