LeaderElectionTest.java

/**
 * Copyright (C) 2015 Red Hat, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.fabric8.kubernetes.client.mock;

import io.fabric8.kubernetes.api.model.ConfigMapBuilder;
import io.fabric8.kubernetes.api.model.coordination.v1.LeaseBuilder;
import io.fabric8.kubernetes.client.KubernetesClient;
import io.fabric8.kubernetes.client.extended.leaderelection.LeaderCallbacks;
import io.fabric8.kubernetes.client.extended.leaderelection.LeaderElectionConfigBuilder;
import io.fabric8.kubernetes.client.extended.leaderelection.resourcelock.ConfigMapLock;
import io.fabric8.kubernetes.client.extended.leaderelection.resourcelock.LeaseLock;
import io.fabric8.kubernetes.client.extended.leaderelection.resourcelock.Lock;
import io.fabric8.kubernetes.client.server.mock.EnableKubernetesMockClient;
import io.fabric8.kubernetes.client.server.mock.KubernetesMockServer;
import org.junit.jupiter.api.Test;

import java.time.Duration;
import java.time.ZonedDateTime;
import java.time.temporal.ChronoUnit;
import java.util.Collections;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;

@EnableKubernetesMockClient
public class LeaderElectionTest {

  KubernetesMockServer server;
  KubernetesClient client;

  @Test
  public void singleLeaderConfigMapLockCreateTest() throws Exception {
    // Given
    server.expect().post().withPath("/api/v1/namespaces/namespace/configmaps")
      .andReturn(200, null).once();
    // When - Then
    testAndAssertSingleLeader("lead-config-map",
      new ConfigMapLock("namespace", "name", "lead-config-map"));
  }

  @Test
  public void singleLeaderConfigMapLockUpdateTest() throws Exception {
    // Given
    server.expect().get().withPath("/api/v1/namespaces/namespace/configmaps/name")
      .andReturn(200, new ConfigMapBuilder()
        .withNewMetadata()
        .withResourceVersion("1")
        .withAnnotations(Collections.singletonMap(
          "control-plane.alpha.kubernetes.io/leader",
          "{\"holderIdentity\": \"not-lead-config-map\", \"leaseDuration\": 100, \"acquireTime\": 0, \"renewTime\": 0}"))
        .endMetadata()
        .build()).always();
    server.expect().put().withPath("/api/v1/namespaces/namespace/configmaps/name")
      .andReturn(200, null).once();
    // When - Then
    testAndAssertSingleLeader("lead-config-map",
      new ConfigMapLock("namespace", "name", "lead-config-map"));
  }

  @Test
  public void singleLeaderLeaseLockCreateTest() throws Exception {
    // Given
    server.expect().post().withPath("/apis/coordination.k8s.io/v1/namespaces/namespace/leases")
      .andReturn(200, null).once();
    // When - Then
    testAndAssertSingleLeader("lead-lease",
      new LeaseLock("namespace", "name", "lead-lease"));
  }

  @Test
  public void singleLeaderLeaseLockUpdateTest() throws Exception {
    // Given
    server.expect().get().withPath("/apis/coordination.k8s.io/v1/namespaces/namespace/leases/name")
      .andReturn(200, new LeaseBuilder()
        .withNewMetadata().withResourceVersion("1").endMetadata()
        .withNewSpec()
        .withHolderIdentity("not-lead-lease")
        .withLeaseDurationSeconds(1)
        .withAcquireTime(ZonedDateTime.now().minus(1, ChronoUnit.YEARS))
        .withRenewTime(ZonedDateTime.now().minus(1, ChronoUnit.YEARS))
        .withLeaseTransitions(0)
        .endSpec()
        .build()).always();
    server.expect().put().withPath("/apis/coordination.k8s.io/v1/namespaces/namespace/leases/name")
      .andReturn(200, null).once();
    // When - Then
    testAndAssertSingleLeader("lead-lease",
      new LeaseLock("namespace", "name", "lead-lease"));
  }

  private void testAndAssertSingleLeader(String id, Lock lock) throws Exception {
    // Given
    final CountDownLatch leaderLatch = new CountDownLatch(1);
    final AtomicReference<String> newLeaderRecord = new AtomicReference<>();
    final AtomicBoolean stoppedLeading = new AtomicBoolean(false);
    final ExecutorService executorService = Executors.newSingleThreadExecutor();
    // When
    final Future<?> leaderElectorTask = executorService.submit(() ->
      assertThrows(InterruptedException.class, () ->
        client.leaderElector()
          .withConfig(new LeaderElectionConfigBuilder()
            .withName("Integration test leader election configuration")
            .withLeaseDuration(Duration.ofSeconds(15L))
            .withLock(lock)
            .withRenewDeadline(Duration.ofSeconds(10L))
            .withRetryPeriod(Duration.ofSeconds(2L))
            .withLeaderCallbacks(new LeaderCallbacks(
              leaderLatch::countDown,
              () -> stoppedLeading.set(true),
              newLeaderRecord::set
            ))
            .build()
          ).build().run()
      )
    );
    // Then
    assertTrue(leaderLatch.await(5, TimeUnit.SECONDS));
    assertEquals(id, newLeaderRecord.get());
    assertEquals(0, leaderLatch.getCount());
    leaderElectorTask.cancel(true);
    executorService.shutdownNow();
    executorService.awaitTermination(5, TimeUnit.SECONDS);
    assertTrue(stoppedLeading.get());
  }
}