Initial support for multi kubernetes clusters for k8s nodes

Change-Id: I6ca132898f8e157e0583de38a637fdc135f21d6f
diff --git a/apps/k8s-node/app/src/test/java/org/onosproject/k8snode/codec/K8sHostCodecTest.java b/apps/k8s-node/app/src/test/java/org/onosproject/k8snode/codec/K8sHostCodecTest.java
new file mode 100644
index 0000000..c7cb041
--- /dev/null
+++ b/apps/k8s-node/app/src/test/java/org/onosproject/k8snode/codec/K8sHostCodecTest.java
@@ -0,0 +1,144 @@
+/*
+ * Copyright 2020-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.k8snode.codec;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.collect.ImmutableSet;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.packet.IpAddress;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.codec.impl.CodecManager;
+import org.onosproject.core.CoreService;
+import org.onosproject.k8snode.api.DefaultK8sHost;
+import org.onosproject.k8snode.api.K8sHost;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
+
+import static junit.framework.TestCase.assertEquals;
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.onosproject.k8snode.api.K8sHostState.INIT;
+import static org.onosproject.k8snode.codec.K8sHostJsonMatcher.matchesK8sHost;
+import static org.onosproject.net.NetTestTools.APP_ID;
+
+public class K8sHostCodecTest {
+
+    MockCodecContext context;
+
+    JsonCodec<K8sHost> k8sHostCodec;
+
+    final CoreService mockCoreService = createMock(CoreService.class);
+    private static final String REST_APP_ID = "org.onosproject.rest";
+
+    /**
+     * Initial setup for this unit test.
+     */
+    @Before
+    public void setUp() {
+        context = new MockCodecContext();
+        k8sHostCodec = new K8sHostCodec();
+
+        assertThat(k8sHostCodec, notNullValue());
+
+        expect(mockCoreService.registerApplication(REST_APP_ID))
+                .andReturn(APP_ID).anyTimes();
+        replay(mockCoreService);
+        context.registerService(CoreService.class, mockCoreService);
+    }
+
+    /**
+     * Tests the kubernetes host encoding.
+     */
+    @Test
+    public void testK8sHostEncode() {
+        K8sHost host = DefaultK8sHost.builder()
+                .hostIp(IpAddress.valueOf("192.168.200.10"))
+                .state(INIT)
+                .nodeNames(ImmutableSet.of("1", "2"))
+                .build();
+
+        ObjectNode hostJson = k8sHostCodec.encode(host, context);
+        assertThat(hostJson, matchesK8sHost(host));
+    }
+
+    /**
+     * Tests the kubernetes host decoding.
+     */
+    @Test
+    public void testK8sHostDecode() throws IOException {
+        K8sHost host = getK8sHost("K8sHost.json");
+
+        assertEquals("192.168.200.10", host.hostIp().toString());
+        assertEquals("INIT", host.state().name());
+    }
+
+    private K8sHost getK8sHost(String resourceName) throws IOException {
+        InputStream jsonStream = K8sHostCodecTest.class.getResourceAsStream(resourceName);
+        JsonNode json = context.mapper().readTree(jsonStream);
+        assertThat(json, notNullValue());
+        K8sHost host = k8sHostCodec.decode((ObjectNode) json, context);
+        assertThat(host, notNullValue());
+        return host;
+    }
+
+    private class MockCodecContext implements CodecContext {
+        private final ObjectMapper mapper = new ObjectMapper();
+        private final CodecManager manager = new CodecManager();
+        private final Map<Class<?>, Object> services = new HashMap<>();
+
+        /**
+         * Constructs a new mock codec context.
+         */
+        public MockCodecContext() {
+            manager.activate();
+        }
+
+        @Override
+        public ObjectMapper mapper() {
+            return mapper;
+        }
+
+        @Override
+        @SuppressWarnings("unchecked")
+        public <T> JsonCodec<T> codec(Class<T> entityClass) {
+            if (entityClass == K8sHost.class) {
+                return (JsonCodec<T>) k8sHostCodec;
+            }
+            return manager.getCodec(entityClass);
+        }
+
+        @SuppressWarnings("unchecked")
+        @Override
+        public <T> T getService(Class<T> serviceClass) {
+            return (T) services.get(serviceClass);
+        }
+
+        // for registering mock services
+        public <T> void registerService(Class<T> serviceClass, T impl) {
+            services.put(serviceClass, impl);
+        }
+    }
+}