chore : add code for blogpost https://rohankanojia.github.io/articles…

…/2024/06/29/effective-kubernetes-testing-kube-api-test/

Signed-off-by: Rohan Kumar <[email protected]>

src/main/java/io/fabric8/openshift/LoginUsingUsernameAndPasswordAndListPods.java

@@ -0,0 +1,26 @@
+package io.fabric8.openshift;
+
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.Pod;
+import io.fabric8.kubernetes.client.Config;
+import io.fabric8.kubernetes.client.ConfigBuilder;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.KubernetesClientBuilder;
+import io.fabric8.openshift.client.OpenShiftClient;
+
+public class LoginUsingUsernameAndPasswordAndListPods {
+  public static void main(String[] args) {
+    Config config = new ConfigBuilder(Config.empty())
+      .withMasterUrl("https://api.crc.testing:6443")
+      .withUsername("kubeadmin")
+      .withPassword("IHiBd-9zJ6H-vICp4-Lpd69")
+      .withTrustCerts()
+      .build();
+
+    try (KubernetesClient kubernetesClient = new KubernetesClientBuilder().withConfig(config).build()) {
+      OpenShiftClient openShiftClient = kubernetesClient.adapt(OpenShiftClient.class);
+
+      openShiftClient.pods().list().getItems().stream().map(Pod::getMetadata).map(ObjectMeta::getName).forEach(System.out::println);
+    }
+  }
+}

writing-tests-with-fabric8/pom.xml

@@ -38,6 +38,11 @@
             <artifactId>kubernetes-junit-jupiter</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.fabric8</groupId>
+            <artifactId>kube-api-test</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>

writing-tests-with-fabric8/src/test/java/io/fabric8/demos/tests/kubeapitest/PodGroupServiceTest.java

@@ -0,0 +1,154 @@
+package io.fabric8.demos.tests.kubeapitest;
+
+import io.fabric8.demos.tests.mockserver.PodGroupService;
+import io.fabric8.kubeapitest.junit.EnableKubeAPIServer;
+import io.fabric8.kubeapitest.junit.KubeConfig;
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.Pod;
+import io.fabric8.kubernetes.api.model.PodBuilder;
+import io.fabric8.kubernetes.api.model.PodList;
+import io.fabric8.kubernetes.api.model.StatusDetails;
+import io.fabric8.kubernetes.client.Config;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.KubernetesClientBuilder;
+import io.fabric8.kubernetes.client.Watch;
+import io.fabric8.kubernetes.client.Watcher;
+import io.fabric8.kubernetes.client.WatcherException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+@EnableKubeAPIServer(
+  // Kubernetes Api Server version
+  kubeAPIVersion = "1.30.0",
+  // Kubernetes Api Server Flags
+  apiServerFlags =  {"--audit-webhook-truncate-enabled"},
+  // Whether modify local kube config
+  updateKubeConfigFile = false
+)
+class PodGroupServiceTest {
+  KubernetesClient kubernetesClient;
+
+  @KubeConfig
+  static String configYaml;
+
+  @BeforeEach
+  void setUp() {
+    kubernetesClient = new KubernetesClientBuilder()
+      .withConfig(Config.fromKubeconfig(configYaml))
+      .build();
+  }
+
+  @Test
+  void list_whenPodsPresent_thenReturnList() {
+    // Given
+    Map<String, String> matchLabel = Collections.singletonMap("app", "list");
+    PodGroupService podGroupService = new PodGroupService(kubernetesClient, matchLabel);
+    // When
+    PodList podList = podGroupService.list();
+
+    // Then
+    assertNotNull(podList);
+  }
+
+  @Test
+  void addToGroup_whenPodProvided_thenShouldUpdatePod() {
+    // Given
+    Map<String, String> matchLabel = Collections.singletonMap("app", "add-to-group");
+    PodGroupService podGroupService = new PodGroupService(kubernetesClient, matchLabel);
+    Pod p1 = createNewPod("p1", "add-to-group");
+
+    // When
+    podGroupService.addToGroup(p1);
+
+    // Then
+    PodList podList = podGroupService.list();
+    assertTrue(podList.getItems().stream().map(Pod::getMetadata).map(ObjectMeta::getName).anyMatch(n -> n.startsWith("p1")));
+  }
+
+  @Test
+  void size_whenPodsAbsent_thenReturnZero() {
+    // Given
+    PodGroupService podGroupService = new PodGroupService(kubernetesClient, Collections.singletonMap("app", "size-zero"));
+
+    // When
+    int result = podGroupService.size();
+
+    // Then
+    assertEquals(0, result);
+  }
+
+  @Test
+  void size_whenPodsPresent_thenReturnActualSize() {
+    // Given
+    PodGroupService podGroupService = new PodGroupService(kubernetesClient, Collections.singletonMap("app", "size-non-zero"));
+    podGroupService.addToGroup(createNewPod("p1", "size-non-zero"));
+    podGroupService.addToGroup(createNewPod("p2", "size-non-zero"));
+
+    // When
+    int result = podGroupService.size();
+
+    // Then
+    assertEquals(2, result);
+  }
+
+  @Test
+  void watch_whenInvoked_shouldMonitorUpdates() throws Exception {
+    // Given
+    PodGroupService podGroupService = new PodGroupService(kubernetesClient, Collections.singletonMap("app", "watch-test"));
+    CountDownLatch eventReceivedLatch = new CountDownLatch(1);
+
+    // When
+    try (Watch ignore = podGroupService.watch(new Watcher<>() {
+      @Override
+      public void eventReceived(Action action, Pod pod) {
+        eventReceivedLatch.countDown();
+      }
+
+      @Override
+      public void onClose(WatcherException e) { }
+    })) {
+      podGroupService.addToGroup(createNewPod("p1-watch", "watch-test"));
+      assertTrue(eventReceivedLatch.await(5, TimeUnit.SECONDS));
+    }
+    // Then
+    assertEquals(0, eventReceivedLatch.getCount());
+  }
+
+  @Test
+  void delete_whenInvoked_shouldDeleteAllMatchingPods() {
+    // Given
+    PodGroupService podGroupService = new PodGroupService(kubernetesClient, Collections.singletonMap("app", "delete-test"));
+    podGroupService.addToGroup(createNewPod("p1", "delete-test"));
+    podGroupService.addToGroup(createNewPod("p2", "delete-test"));
+
+    // When
+    List<StatusDetails> deleteStatusDetails = podGroupService.delete();
+    int sizeAfterDelete = podGroupService.size();
+
+    // Then
+    assertEquals(2, deleteStatusDetails.size());
+    assertEquals(0, sizeAfterDelete);
+  }
+
+  private Pod createNewPod(String generateName, String appLabelValue) {
+    return new PodBuilder()
+      .withNewMetadata().withGenerateName(generateName).withLabels(Collections.singletonMap("app", appLabelValue)).endMetadata()
+      .withNewSpec()
+      .addNewContainer()
+      .withName("demo-container")
+      .withImage("alpine:latest")
+      .endContainer()
+      .endSpec()
+      .build();
+  }
+}