LeaderContext

Author: Gytis Trikleris

spring-cloud-kubernetes-leader/src/main/java/org/springframework/cloud/kubernetes/leader/LeaderContext.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2018 Red Hat, Inc, and individual contributors.
+ *
+ * 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 org.springframework.cloud.kubernetes.leader;
+
+import org.springframework.integration.leader.Candidate;
+import org.springframework.integration.leader.Context;
+
+/**
+ * @author <a href="mailto:[email protected]">Gytis Trikleris</a>
+ */
+public class LeaderContext implements Context {
+
+	private final Candidate candidate;
+
+	private final LeadershipController leadershipController;
+
+	public LeaderContext(Candidate candidate, LeadershipController leadershipController) {
+		this.candidate = candidate;
+		this.leadershipController = leadershipController;
+	}
+
+	@Override
+	public boolean isLeader() {
+		Leader leader = leadershipController.getLeader(candidate.getRole());
+		if (leader == null) {
+			return false;
+		}
+
+		return candidate.getId().equals(leader.getId());
+	}
+
+	@Override
+	public void yield() {
+		leadershipController.revoke(candidate);
+	}
+}

spring-cloud-kubernetes-leader/src/main/java/org/springframework/cloud/kubernetes/leader/LeadershipController.java

@@ -24,6 +24,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.integration.leader.Candidate;
+import org.springframework.integration.leader.Context;
 import org.springframework.integration.leader.event.LeaderEventPublisher;
 
 /**
@@ -123,17 +124,19 @@ private void updateLeaderConfigMap(Candidate candidate, ConfigMap configMap) {
 	}
 
 	private void handleOnGranted(Candidate candidate) {
-		leaderEventPublisher.publishOnGranted(this, null, candidate.getRole());
+		Context context = new LeaderContext(candidate, this);
+		leaderEventPublisher.publishOnGranted(this, context, candidate.getRole());
 		try {
-			candidate.onGranted(null); // TODO context
+			candidate.onGranted(context);
 		} catch (InterruptedException e) {
 			LOGGER.warn(e.getMessage());
 			Thread.currentThread().interrupt();
 		}
 	}
 
 	private void handleOnFailed(Candidate candidate) {
-		leaderEventPublisher.publishOnFailedToAcquire(this, null, candidate.getRole());  // TODO context
+		Context context = new LeaderContext(candidate, this);
+		leaderEventPublisher.publishOnFailedToAcquire(this, context, candidate.getRole());
 	}
 
 	private Map<String, String> getLeaderData(Candidate candidate) {

spring-cloud-kubernetes-leader/src/test/java/org/springframework/cloud/kubernetes/leader/LeaderContextTest.java

@@ -0,0 +1,77 @@
+package org.springframework.cloud.kubernetes.leader;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.springframework.integration.leader.Candidate;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.verify;
+
+/**
+ * @author <a href="mailto:[email protected]">Gytis Trikleris</a>
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class LeaderContextTest {
+
+	private static final String ROLE = "test-role";
+
+	private static final String ID = "test-id";
+
+	@Mock
+	private Candidate mockCandidate;
+
+	@Mock
+	private LeadershipController mockLeadershipController;
+
+	@Mock
+	private Leader mockLeader;
+
+	private LeaderContext leaderContext;
+
+	@Before
+	public void before() {
+		given(mockCandidate.getRole()).willReturn(ROLE);
+		given(mockCandidate.getId()).willReturn(ID);
+
+		leaderContext = new LeaderContext(mockCandidate, mockLeadershipController);
+	}
+
+	@Test
+	public void testIsLeaderWithoutLeader() {
+		boolean result = leaderContext.isLeader();
+
+		assertThat(result).isFalse();
+	}
+
+	@Test
+	public void testIsLeaderWithAnotherLeader() {
+		given(mockLeadershipController.getLeader(ROLE)).willReturn(mockLeader);
+		given(mockLeader.getId()).willReturn("another-test-id");
+
+		boolean result = leaderContext.isLeader();
+
+		assertThat(result).isFalse();
+	}
+
+	@Test
+	public void testIsLeaderWhenLeader() {
+		given(mockLeadershipController.getLeader(ROLE)).willReturn(mockLeader);
+		given(mockLeader.getId()).willReturn(ID);
+
+		boolean result = leaderContext.isLeader();
+
+		assertThat(result).isTrue();
+	}
+
+	@Test
+	public void shouldYieldLeadership() {
+		leaderContext.yield();
+
+		verify(mockLeadershipController).revoke(mockCandidate);
+	}
+
+}

spring-cloud-kubernetes-leader/src/test/java/org/springframework/cloud/kubernetes/leader/LeadershipControllerTest.java

@@ -8,13 +8,15 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnitRunner;
 import org.springframework.integration.leader.Candidate;
 import org.springframework.integration.leader.event.LeaderEventPublisher;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.times;
@@ -67,7 +69,7 @@ public void shouldAcquireWithoutExistingConfigMap() {
 
 		assertThat(result).isTrue();
 		verify(mockKubernetesHelper).createConfigMap(Collections.singletonMap(PREFIX + ROLE, ID));
-		verify(mockLeaderEventPublisher).publishOnGranted(leadershipController, null, ROLE);
+		verifyPublishOnGranted();
 	}
 
 	@Test
@@ -78,7 +80,7 @@ public void shouldAcquireWithExistingConfigMap() {
 
 		assertThat(result).isTrue();
 		verify(mockKubernetesHelper).updateConfigMap(mockConfigMap, leaderData);
-		verify(mockLeaderEventPublisher).publishOnGranted(leadershipController, null, ROLE);
+		verifyPublishOnGranted();
 	}
 
 	@Test
@@ -109,7 +111,7 @@ public void shouldTakeOverLeadershipFromInvalidLeader() {
 
 		assertThat(result).isTrue();
 		verify(mockKubernetesHelper).updateConfigMap(mockConfigMap, Collections.singletonMap(PREFIX + ROLE, anotherId));
-		verify(mockLeaderEventPublisher).publishOnGranted(leadershipController, null, ROLE);
+		verifyPublishOnGranted();
 	}
 
 	@Test
@@ -124,7 +126,7 @@ public void shouldFailToAcquireBecauseOfExistingLeader() {
 		assertThat(result).isFalse();
 		verify(mockKubernetesHelper, times(0)).createConfigMap(any());
 		verify(mockKubernetesHelper, times(0)).updateConfigMap(any(), any());
-		verify(mockLeaderEventPublisher).publishOnFailedToAcquire(leadershipController, null, ROLE);
+		verifyPublishOnFailedToAcquire();
 	}
 
 	@Test
@@ -134,7 +136,7 @@ public void shouldFailToAcquireBecauseOfException() {
 		boolean result = leadershipController.acquire(mockCandidate);
 
 		assertThat(result).isFalse();
-		verify(mockLeaderEventPublisher).publishOnFailedToAcquire(leadershipController, null, ROLE);
+		verifyPublishOnFailedToAcquire();
 	}
 
 	@Test
@@ -182,4 +184,20 @@ public void shouldHandleFailureWhenGettingLeader() {
 		assertThat(leader).isNull();
 	}
 
+	private void verifyPublishOnGranted() {
+		ArgumentCaptor<LeaderContext> leaderContextCaptor = ArgumentCaptor.forClass(LeaderContext.class);
+		verify(mockLeaderEventPublisher).publishOnGranted(eq(leadershipController),
+			leaderContextCaptor.capture(), eq(ROLE));
+		LeaderContext expectedLeaderContext = new LeaderContext(mockCandidate, leadershipController);
+		assertThat(leaderContextCaptor.getValue()).isEqualToComparingFieldByField(expectedLeaderContext);
+	}
+
+	public void verifyPublishOnFailedToAcquire() {
+		ArgumentCaptor<LeaderContext> leaderContextCaptor = ArgumentCaptor.forClass(LeaderContext.class);
+		verify(mockLeaderEventPublisher).publishOnFailedToAcquire(eq(leadershipController),
+			leaderContextCaptor.capture(), eq(ROLE));
+		LeaderContext expectedLeaderContext = new LeaderContext(mockCandidate, leadershipController);
+		assertThat(leaderContextCaptor.getValue()).isEqualToComparingFieldByField(expectedLeaderContext);
+	}
+
 }