[ONOS-7935] Add k8s pod store and manager with unit tests

Change-Id: If4104a2800556bf9777c159eb3b5bd175bc141ae
diff --git a/apps/k8s-networking/app/src/test/java/org/onosproject/k8snetworking/impl/K8sPodManagerTest.java b/apps/k8s-networking/app/src/test/java/org/onosproject/k8snetworking/impl/K8sPodManagerTest.java
new file mode 100644
index 0000000..3894f9c
--- /dev/null
+++ b/apps/k8s-networking/app/src/test/java/org/onosproject/k8snetworking/impl/K8sPodManagerTest.java
@@ -0,0 +1,218 @@
+/*
+ * Copyright 2019-present Open Networking Foundation
+ *
+ * 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.onosproject.k8snetworking.impl;
+
+import com.google.common.collect.Lists;
+import com.google.common.util.concurrent.MoreExecutors;
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.Pod;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.junit.TestUtils;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreServiceAdapter;
+import org.onosproject.core.DefaultApplicationId;
+import org.onosproject.event.Event;
+import org.onosproject.k8snetworking.api.K8sPodEvent;
+import org.onosproject.k8snetworking.api.K8sPodListener;
+import org.onosproject.store.service.TestStorageService;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.onosproject.k8snetworking.api.K8sPodEvent.Type.K8S_POD_CREATED;
+import static org.onosproject.k8snetworking.api.K8sPodEvent.Type.K8S_POD_REMOVED;
+import static org.onosproject.k8snetworking.api.K8sPodEvent.Type.K8S_POD_UPDATED;
+
+/**
+ * Unit tests for kubernetes pod manager.
+ */
+public class K8sPodManagerTest {
+
+    private static final ApplicationId TEST_APP_ID = new DefaultApplicationId(1, "test");
+
+    private static final String UNKNOWN_UID = "unknown_uid";
+    private static final String UPDATED_UID = "updated_uid";
+    private static final String UPDATED_NAME = "updated_name";
+
+    private static final String POD_UID = "pod_uid";
+    private static final String POD_NAME = "pod_name";
+
+    private static final Pod POD = createK8sPod(POD_UID, POD_NAME);
+    private static final Pod POD_UPDATED = createK8sPod(POD_UID, UPDATED_NAME);
+
+    private final TestK8sPodListener testListener = new TestK8sPodListener();
+
+    private K8sPodManager target;
+    private DistributedK8sPodStore k8sPodStore;
+
+    @Before
+    public void setUp() throws Exception {
+        k8sPodStore = new DistributedK8sPodStore();
+        TestUtils.setField(k8sPodStore, "coreService", new TestCoreService());
+        TestUtils.setField(k8sPodStore, "storageService", new TestStorageService());
+        TestUtils.setField(k8sPodStore, "eventExecutor", MoreExecutors.newDirectExecutorService());
+        k8sPodStore.activate();
+
+        target = new K8sPodManager();
+        TestUtils.setField(target, "coreService", new TestCoreService());
+        target.k8sPodStore = k8sPodStore;
+        target.addListener(testListener);
+        target.activate();
+    }
+
+    @After
+    public void tearDown() {
+        target.removeListener(testListener);
+        k8sPodStore.deactivate();
+        target.deactivate();
+        k8sPodStore = null;
+        target = null;
+    }
+
+    /**
+     * Tests if getting all pods return correct set of pods.
+     */
+    @Test
+    public void testGetPods() {
+        createBasicPods();
+        assertEquals("Number of pods did not match", 1, target.pods().size());
+    }
+
+    /**
+     * Tests if getting a pod with UID returns the correct pod.
+     */
+    @Test
+    public void testGetPodByUid() {
+        createBasicPods();
+        assertNotNull("Pod did not match", target.pod(POD_UID));
+        assertNull("Pod did not match", target.pod(UNKNOWN_UID));
+    }
+
+    /**
+     * Tests creating and removing a pod, and checks if it triggers proper events.
+     */
+    @Test
+    public void testCreateAndRemovePod() {
+        target.createPod(POD);
+        assertEquals("Number of pods did not match", 1, target.pods().size());
+        assertNotNull("Pod was not created", target.pod(POD_UID));
+
+        target.removePod(POD_UID);
+        assertEquals("Number of pods did not match", 0, target.pods().size());
+        assertNull("Pod was not removed", target.pod(POD_UID));
+
+        validateEvents(K8S_POD_CREATED, K8S_POD_REMOVED);
+    }
+
+    /**
+     * Tests updating a pod, and checks if it triggers proper events.
+     */
+    @Test
+    public void testCreateAndUpdatePod() {
+        target.createPod(POD);
+        assertEquals("Number of pods did not match", 1, target.pods().size());
+        assertEquals("Pod did not match", POD_NAME,
+                target.pod(POD_UID).getMetadata().getName());
+
+        target.updatePod(POD_UPDATED);
+
+        assertEquals("Number of pods did not match", 1, target.pods().size());
+        assertEquals("Pod did not match", UPDATED_NAME,
+                target.pod(POD_UID).getMetadata().getName());
+        validateEvents(K8S_POD_CREATED, K8S_POD_UPDATED);
+    }
+
+    /**
+     * Tests if creating a null pod fails with an exception.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testCreateNullPod() {
+        target.createPod(null);
+    }
+
+    /**
+     * Tests if creating a duplicate pod fails with an exception.
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateDuplicatePod() {
+        target.createPod(POD);
+        target.createPod(POD);
+    }
+
+    /**
+     * Tests if removing pod with null ID fails with an exception.
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void testRemovePodWithNull() {
+        target.removePod(null);
+    }
+
+    /**
+     * Tests if updating an unregistered pod fails with an exception.
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void testUpdateUnregisteredPod() {
+        target.updatePod(POD);
+    }
+
+    private void createBasicPods() {
+        target.createPod(POD);
+    }
+
+    private static Pod createK8sPod(String uid, String name) {
+        ObjectMeta meta = new ObjectMeta();
+        meta.setUid(uid);
+        meta.setName(name);
+
+        Pod pod = new Pod();
+        pod.setApiVersion("v1");
+        pod.setKind("pod");
+        pod.setMetadata(meta);
+
+        return pod;
+    }
+
+    private static class TestCoreService extends CoreServiceAdapter {
+
+        @Override
+        public ApplicationId registerApplication(String name) {
+            return TEST_APP_ID;
+        }
+    }
+
+    private static class TestK8sPodListener implements K8sPodListener {
+        private List<K8sPodEvent> events = Lists.newArrayList();
+
+        @Override
+        public void event(K8sPodEvent event) {
+            events.add(event);
+        }
+    }
+
+    private void validateEvents(Enum... types) {
+        int i = 0;
+        assertEquals("Number of events did not match", types.length, testListener.events.size());
+        for (Event event : testListener.events) {
+            assertEquals("Incorrect event received", types[i], event.type());
+            i++;
+        }
+        testListener.events.clear();
+    }
+}