Adding example for APEX gRPC plugin for CDS interaction

Change-Id: I8361eb0cbe74c3548ca98f3005bc37f5a1f91747
Issue-ID: POLICY-2436
Signed-off-by: a.sreekumar <ajith.sreekumar@est.tech>

4 files changed, 346 insertions, 0 deletions

diff --git a/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestDummyGrpcServer.java b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestDummyGrpcServer.java
new file mode 100644
index 000000000..bef0a81c8
--- /dev/null
+++ b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestDummyGrpcServer.java
@@ -0,0 +1,95 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Nordix 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.policy.apex.examples.grpc;
+
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.util.JsonFormat;
+import io.grpc.Server;
+import io.grpc.netty.NettyServerBuilder;
+import io.grpc.stub.StreamObserver;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import org.onap.ccsdk.cds.controllerblueprints.processing.api.BluePrintProcessingServiceGrpc.BluePrintProcessingServiceImplBase;
+import org.onap.ccsdk.cds.controllerblueprints.processing.api.ExecutionServiceInput;
+import org.onap.ccsdk.cds.controllerblueprints.processing.api.ExecutionServiceOutput;
+import org.onap.ccsdk.cds.controllerblueprints.processing.api.ExecutionServiceOutput.Builder;
+import org.onap.policy.apex.service.engine.event.ApexEventRuntimeException;
+
+/**
+ * The Class GrpcTestDummyGrpcServer creates a dummy gRPC server to mimic a CDS implementation.
+ */
+public class GrpcTestDummyGrpcServer {
+    private Server server;
+
+    public GrpcTestDummyGrpcServer(String host, int port) {
+        // Implement the dummy gRPC server
+        BluePrintProcessingServiceImplBase testCdsBlueprintServerImpl = new BluePrintProcessingServiceImplBase() {
+            @Override
+            public StreamObserver<ExecutionServiceInput> process(
+                final StreamObserver<ExecutionServiceOutput> responseObserver) {
+                return new StreamObserver<ExecutionServiceInput>() {
+                    @Override
+                    public void onNext(final ExecutionServiceInput executionServiceInput) {
+                        String responseString = "";
+                        try {
+                            responseString = Files.readString(Paths.get(
+                                "src/main/resources/examples/events/APEXgRPC/CreateSubscriptionResponseEvent.json"));
+                        } catch (IOException e) {
+                            throw new ApexEventRuntimeException("Cannot read executionServiceOutput from file", e);
+                        }
+                        ExecutionServiceOutput executionServiceOutput;
+                        Builder builder = ExecutionServiceOutput.newBuilder();
+                        try {
+                            JsonFormat.parser().ignoringUnknownFields().merge(responseString, builder);
+                            executionServiceOutput = builder.build();
+                            responseObserver.onNext(executionServiceOutput);
+                        } catch (InvalidProtocolBufferException e) {
+                            throw new ApexEventRuntimeException(
+                                "Output string cannot be converted to ExecutionServiceOutput type for gRPC request."
+                                    + e);
+                        }
+                    }
+
+                    @Override
+                    public void onError(final Throwable throwable) {
+                        responseObserver.onError(throwable);
+                    }
+
+                    @Override
+                    public void onCompleted() {
+                        responseObserver.onCompleted();
+                    }
+                };
+            }
+        };
+        server = NettyServerBuilder.forAddress(new InetSocketAddress(host, port)).addService(testCdsBlueprintServerImpl)
+            .build();
+    }
+
+    public void start() throws IOException {
+        server.start();
+    }
+
+    public void stop() {
+        server.shutdown();
+    }
+}
diff --git a/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestRestSimEndpoint.java b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestRestSimEndpoint.java
new file mode 100644
index 000000000..4e88afe83
--- /dev/null
+++ b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestRestSimEndpoint.java
@@ -0,0 +1,93 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Nordix 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.examples.grpc;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.Response;
+import org.slf4j.ext.XLogger;
+import org.slf4j.ext.XLoggerFactory;
+
+/**
+ * The Class GrpcTestRestSimEndpoint creates rest server endpoints for simulating sending/receiving events on DMaaP.
+ */
+@Path("/sim")
+public class GrpcTestRestSimEndpoint {
+    private static final XLogger LOGGER = XLoggerFactory.getXLogger(GrpcTestRestSimEndpoint.class);
+    private static String loggedOutputEvent = null;
+    private final Object lock = new Object();
+
+    /**
+     * DCAE input of events (simulation of DMaaP). This input event triggers the policy
+     *
+     * @param timeout the timeout to wait for
+     * @return the response
+     * @throws IOException on I/O errors
+     */
+    @Path("events/unauthenticated.DCAE_CL_OUTPUT/APEX/1")
+    @GET
+    public Response dcaeClOutput(@QueryParam("timeout") final int timeout) throws IOException {
+        String createSubscriptionRequest =
+            Files.readString(Paths.get("src/main/resources/examples/events/APEXgRPC/CreateSubscriptionEvent.json"));
+        LOGGER.info("Create subscription request received: \n {}", createSubscriptionRequest);
+
+        return Response.status(200).entity(createSubscriptionRequest).build();
+    }
+
+    /**
+     * Post to Policy management log (Simulation of DMaaP).
+     *
+     * @param jsonString the json string
+     * @return the response
+     */
+    @Path("/events/POLICY_CL_MGT")
+    @POST
+    public Response policyLogRequest(final String jsonString) {
+        LOGGER.info("\n*** POLICY LOG ENTRY START ***\n {} \n *** POLICY LOG ENTRY END ***", jsonString);
+        synchronized (lock) {
+            loggedOutputEvent = jsonString;
+        }
+        return Response.status(200).build();
+    }
+
+    /**
+     * Get the logged event for test verification.
+     *
+     * @return the response
+     */
+    @Path("/event/getLoggedEvent")
+    @GET
+    public Response getDetails() {
+        String loggedEvent;
+        synchronized (lock) {
+            loggedEvent = loggedOutputEvent;
+        }
+        if (null == loggedEvent) {
+            return Response.status(500).entity("Error: Log event not yet generated.").build();
+        }
+        return Response.status(200).entity(loggedEvent).build();
+    }
+}
diff --git a/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestServerSim.java b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestServerSim.java
new file mode 100644
index 000000000..ae35d1ff2
--- /dev/null
+++ b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/GrpcTestServerSim.java
@@ -0,0 +1,73 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Nordix 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.examples.grpc;
+
+import java.io.IOException;
+import org.onap.policy.common.endpoints.http.server.HttpServletServer;
+import org.onap.policy.common.endpoints.http.server.HttpServletServerFactoryInstance;
+import org.onap.policy.common.gson.GsonMessageBodyHandler;
+import org.onap.policy.common.utils.network.NetworkUtil;
+
+/**
+ * The Class GrpcTestServerSim that manages test servers for REST and gRPC requests for the test.
+ */
+public class GrpcTestServerSim {
+    private static final String HOST = "localhost";
+    private HttpServletServer restServer;
+    private GrpcTestDummyGrpcServer grpcServer;
+
+    /**
+     * Instantiates a new REST simulator for DMaaP requests.
+     *
+     * @throws InterruptedException interrupted exception
+     * @throws IOException io exception
+     */
+    public GrpcTestServerSim() throws InterruptedException, IOException {
+        int restServerPort = 54321;
+        restServer = HttpServletServerFactoryInstance.getServerFactory().build("GrpcTestRestSimEndpoint", false, HOST,
+            restServerPort, "/GrpcTestRestSim", false, false);
+        restServer.addServletClass(null, GrpcTestRestSimEndpoint.class.getName());
+        restServer.setSerializationProvider(GsonMessageBodyHandler.class.getName());
+        restServer.start();
+        if (!NetworkUtil.isTcpPortOpen(HOST, restServerPort, 2000, 1L)) {
+            throw new IllegalStateException("port " + restServerPort + " is still not in use");
+        }
+
+        int grpcServerPort = 54322;
+        grpcServer = new GrpcTestDummyGrpcServer(HOST, grpcServerPort);
+        grpcServer.start();
+        if (!NetworkUtil.isTcpPortOpen(HOST, grpcServerPort, 2000, 1L)) {
+            throw new IllegalStateException("port " + grpcServerPort + " is still not in use");
+        }
+    }
+
+    /**
+     * Tear down.
+     */
+    public void tearDown() {
+        if (restServer != null) {
+            restServer.stop();
+        }
+        if (grpcServer != null) {
+            grpcServer.stop();
+        }
+    }
+}
diff --git a/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/TestApexGrpcExample.java b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/TestApexGrpcExample.java
new file mode 100644
index 000000000..06d1d33f9
--- /dev/null
+++ b/examples/examples-grpc/src/test/java/org/onap/policy/apex/examples/grpc/TestApexGrpcExample.java
@@ -0,0 +1,85 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Nordix 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.policy.apex.examples.grpc;
+
+import static org.awaitility.Awaitility.await;
+import static org.junit.Assert.assertEquals;
+
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.concurrent.TimeUnit;
+import javax.ws.rs.client.Client;
+import javax.ws.rs.client.ClientBuilder;
+import javax.ws.rs.core.Response;
+import org.junit.Test;
+import org.onap.policy.apex.auth.clieditor.ApexCommandLineEditorMain;
+import org.onap.policy.apex.service.engine.main.ApexMain;
+
+/**
+ * Test class to run an example policy for APEX-CDS interaction over gRPC.
+ * Event received on unauthenticated.DCAE_CL_OUTPUT DMaaP topic (dummy REST Endpoint here) triggers the policy
+ * Based on the event, a create/delete subscription gRPC request is triggered to the CDS (a dummy gRPC server here).
+ * Response received from CDS is used to send a final output Log event on POLICY_CL_MGT topic.
+ */
+public class TestApexGrpcExample {
+    @Test
+    public void testGrpcExample() throws Exception {
+        // @formatter:off
+        final String[] cliArgs = new String[] {
+            "-c",
+            "src/main/resources/policy/APEXgRPCPolicy.apex",
+            "-l",
+            "target/APEXgRPCPolicyModel.log",
+            "-o",
+            "target/classes/APEXgRPCPolicy.json"
+        };
+        // @formatter:on
+
+        new ApexCommandLineEditorMain(cliArgs);
+
+        // @formatter:off
+        final String[] apexArgs = {
+            "-rfr",
+            "target/classes",
+            "-c",
+            "src/main/resources/examples/config/APEXgRPC/ApexConfig.json",
+            "-m",
+            "target/classes/APEXgRPCPolicy.json"
+        };
+        // @formatter:on
+
+        GrpcTestServerSim sim = new GrpcTestServerSim();
+        final Client client = ClientBuilder.newClient();
+        String expectedLoggedOutputEvent = Files
+            .readString(Paths.get("src/main/resources/examples/events/APEXgRPC/LogEvent.json")).replaceAll("\r", "");
+        final ApexMain apexMain = new ApexMain(apexArgs);
+
+        String getLoggedEventUrl = "http://localhost:54321/GrpcTestRestSim/sim/event/getLoggedEvent";
+        // wait for success response code to be received, until a timeout
+        await().atMost(5000, TimeUnit.MILLISECONDS).until(() -> {
+            return 200 == client.target(getLoggedEventUrl).request("application/json").get().getStatus();
+        });
+        apexMain.shutdown();
+        Response response = client.target(getLoggedEventUrl).request("application/json").get();
+        sim.tearDown();
+        String responseEntity = response.readEntity(String.class);
+        assertEquals(expectedLoggedOutputEvent, responseEntity);
+    }
+}