Adding health check endpoint to distribution

* Adding health check REST endpoint to distribution service.
* Adding isAlive field to DistributionActivator to fetch the health
  status.
* Adding parameter group for rest server parameters.
* Adding DistributionRestController for hosting all the rest endpoints
  in distribution service.
* Adding DistributionRestServer to manage lifecycle of distribution rest server.
* Adding ParameterValidationUtils utility class for common validations.
  Plan is to move this class to policy-common for wider use later.
* Adding test cases for all new code added.
* Refering common classes from policy/common

Change-Id: I246d57133ed1f0c3548bcdee173d7b64fb368abc
Issue-ID: POLICY-1035
Signed-off-by: ramverma <ram.krishna.verma@ericsson.com>

5 files changed, 246 insertions, 17 deletions

diff --git a/main/src/test/java/org/onap/policy/distribution/main/parameters/CommonTestData.java b/main/src/test/java/org/onap/policy/distribution/main/parameters/CommonTestData.java
index 0903b070..59f551cf 100644
--- a/main/src/test/java/org/onap/policy/distribution/main/parameters/CommonTestData.java
+++ b/main/src/test/java/org/onap/policy/distribution/main/parameters/CommonTestData.java
@@ -38,6 +38,10 @@ import org.onap.policy.distribution.reception.parameters.ReceptionHandlerParamet
  */
 public class CommonTestData {
 
+    private static final String REST_SERVER_PASSWORD = "zb!XztG34";
+    private static final String REST_SERVER_USER = "healthcheck";
+    private static final int REST_SERVER_PORT = 6969;
+    private static final String REST_SERVER_HOST = "0.0.0.0";
     public static final String DISTRIBUTION_GROUP_NAME = "SDCDistributionGroup";
     public static final String DECODER_TYPE = "TOSCA";
     public static final String DECODER_CLASS_NAME =
@@ -56,6 +60,23 @@ public class CommonTestData {
      * Returns an instance of ReceptionHandlerParameters for test cases.
      *
      * @param isEmpty boolean value to represent that object created should be empty or not
+     * @return the restServerParameters object
+     */
+    public RestServerParameters getRestServerParameters(final boolean isEmpty) {
+        final RestServerParameters restServerParameters;
+        if (!isEmpty) {
+            restServerParameters = new RestServerParameters(REST_SERVER_HOST, REST_SERVER_PORT, REST_SERVER_USER,
+                    REST_SERVER_PASSWORD);
+        } else {
+            restServerParameters = new RestServerParameters(null, 0, null, null);
+        }
+        return restServerParameters;
+    }
+
+    /**
+     * Returns an instance of ReceptionHandlerParameters for test cases.
+     *
+     * @param isEmpty boolean value to represent that object created should be empty or not
      * @return the receptionHandlerParameters object
      */
     public Map<String, ReceptionHandlerParameters> getReceptionHandlerParameters(final boolean isEmpty) {
@@ -66,9 +87,8 @@ public class CommonTestData {
             final Map<String, PolicyForwarderParameters> policyForwarders = getPolicyForwarders(isEmpty);
             final PSSDConfigurationParametersGroup pssdConfiguration = getPSSDConfigurationParametersGroup(isEmpty);;
             final PluginHandlerParameters pHParameters = new PluginHandlerParameters(policyDecoders, policyForwarders);
-            final ReceptionHandlerParameters rhParameters =
-                    new ReceptionHandlerParameters(RECEPTION_HANDLER_TYPE, RECEPTION_HANDLER_CLASS_NAME,
-                        pssdConfiguration, pHParameters);
+            final ReceptionHandlerParameters rhParameters = new ReceptionHandlerParameters(RECEPTION_HANDLER_TYPE,
+                    RECEPTION_HANDLER_CLASS_NAME, pssdConfiguration, pHParameters);
             receptionHandlerParameters.put(SDC_RECEPTION_HANDLER_KEY, rhParameters);
         }
         return receptionHandlerParameters;
@@ -88,12 +108,11 @@ public class CommonTestData {
             final List<String> artifactTypes = new ArrayList<>();
             artifactTypes.add("TOSCA_CSAR");
             pssdConfiguration = new PSSDConfigurationParametersGroup.PSSDConfigurationBuilder()
-                                    .setAsdcAddress("localhost").setMessageBusAddress(messageBusAddress)
-                                    .setUser("policy").setPassword("policy").setPollingInterval(20)
-                                    .setPollingTimeout(30).setConsumerId("policy-id").setArtifactTypes(artifactTypes)
-                                    .setConsumerGroup("policy-group").setEnvironmentName("TEST").setKeystorePath("")
-                                    .setKeystorePassword("").setActiveserverTlsAuth(false)
-                                    .setIsFilterinEmptyResources(true).setIsUseHttpsWithDmaap(false).build();
+                    .setAsdcAddress("localhost").setMessageBusAddress(messageBusAddress).setUser("policy")
+                    .setPassword("policy").setPollingInterval(20).setPollingTimeout(30).setConsumerId("policy-id")
+                    .setArtifactTypes(artifactTypes).setConsumerGroup("policy-group").setEnvironmentName("TEST")
+                    .setKeystorePath("").setKeystorePassword("").setActiveserverTlsAuth(false)
+                    .setIsFilterinEmptyResources(true).setIsUseHttpsWithDmaap(false).build();
         } else {
             pssdConfiguration = new PSSDConfigurationParametersGroup.PSSDConfigurationBuilder().build();
         }
diff --git a/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterGroup.java b/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterGroup.java
index 70317971..f6ed0f98 100644
--- a/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterGroup.java
+++ b/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterGroup.java
@@ -41,13 +41,20 @@ public class TestDistributionParameterGroup {
 
     @Test
     public void testDistributionParameterGroup() {
+        final RestServerParameters restServerParameters = commonTestData.getRestServerParameters(false);
         final Map<String, ReceptionHandlerParameters> receptionHandlerParameters =
                 commonTestData.getReceptionHandlerParameters(false);
 
-        final DistributionParameterGroup distributionParameters =
-                new DistributionParameterGroup(CommonTestData.DISTRIBUTION_GROUP_NAME, receptionHandlerParameters);
+        final DistributionParameterGroup distributionParameters = new DistributionParameterGroup(
+                CommonTestData.DISTRIBUTION_GROUP_NAME, restServerParameters, receptionHandlerParameters);
         final GroupValidationResult validationResult = distributionParameters.validate();
         assertTrue(validationResult.isValid());
+        assertEquals(restServerParameters.getHost(), distributionParameters.getRestServerParameters().getHost());
+        assertEquals(restServerParameters.getPort(), distributionParameters.getRestServerParameters().getPort());
+        assertEquals(restServerParameters.getUserName(),
+                distributionParameters.getRestServerParameters().getUserName());
+        assertEquals(restServerParameters.getPassword(),
+                distributionParameters.getRestServerParameters().getPassword());
         assertEquals(CommonTestData.DISTRIBUTION_GROUP_NAME, distributionParameters.getName());
         assertEquals(receptionHandlerParameters.get(CommonTestData.SDC_RECEPTION_HANDLER_KEY).getReceptionHandlerType(),
                 distributionParameters.getReceptionHandlerParameters().get(CommonTestData.SDC_RECEPTION_HANDLER_KEY)
@@ -64,11 +71,12 @@ public class TestDistributionParameterGroup {
 
     @Test
     public void testDistributionParameterGroup_NullName() {
+        final RestServerParameters restServerParameters = commonTestData.getRestServerParameters(false);
         final Map<String, ReceptionHandlerParameters> receptionHandlerParameters =
                 commonTestData.getReceptionHandlerParameters(false);
 
         final DistributionParameterGroup distributionParameters =
-                new DistributionParameterGroup(null, receptionHandlerParameters);
+                new DistributionParameterGroup(null, restServerParameters, receptionHandlerParameters);
         final GroupValidationResult validationResult = distributionParameters.validate();
         assertFalse(validationResult.isValid());
         assertEquals(null, distributionParameters.getName());
@@ -89,11 +97,12 @@ public class TestDistributionParameterGroup {
 
     @Test
     public void testDistributionParameterGroup_EmptyName() {
+        final RestServerParameters restServerParameters = commonTestData.getRestServerParameters(false);
         final Map<String, ReceptionHandlerParameters> receptionHandlerParameters =
                 commonTestData.getReceptionHandlerParameters(false);
 
         final DistributionParameterGroup distributionParameters =
-                new DistributionParameterGroup("", receptionHandlerParameters);
+                new DistributionParameterGroup("", restServerParameters, receptionHandlerParameters);
         final GroupValidationResult validationResult = distributionParameters.validate();
         assertFalse(validationResult.isValid());
         assertEquals("", distributionParameters.getName());
@@ -114,9 +123,10 @@ public class TestDistributionParameterGroup {
 
     @Test
     public void testDistributionParameterGroup_NullReceptionHandlerParameters() {
+        final RestServerParameters restServerParameters = commonTestData.getRestServerParameters(false);
         try {
             final DistributionParameterGroup distributionParameters =
-                    new DistributionParameterGroup(CommonTestData.DISTRIBUTION_GROUP_NAME, null);
+                    new DistributionParameterGroup(CommonTestData.DISTRIBUTION_GROUP_NAME, restServerParameters, null);
             distributionParameters.validate();
             fail("test should throw an exception here");
         } catch (final Exception e) {
@@ -127,11 +137,12 @@ public class TestDistributionParameterGroup {
 
     @Test
     public void testDistributionParameterGroup_EmptyReceptionHandlerParameters() {
+        final RestServerParameters restServerParameters = commonTestData.getRestServerParameters(false);
         final Map<String, ReceptionHandlerParameters> receptionHandlerParameters =
                 commonTestData.getReceptionHandlerParameters(true);
         try {
-            final DistributionParameterGroup distributionParameters =
-                    new DistributionParameterGroup(CommonTestData.DISTRIBUTION_GROUP_NAME, receptionHandlerParameters);
+            final DistributionParameterGroup distributionParameters = new DistributionParameterGroup(
+                    CommonTestData.DISTRIBUTION_GROUP_NAME, restServerParameters, receptionHandlerParameters);
             distributionParameters.validate();
             fail("test should throw an exception here");
         } catch (final Exception e) {
@@ -139,4 +150,19 @@ public class TestDistributionParameterGroup {
         }
 
     }
+
+    @Test
+    public void testDistributionParameterGroup_EmptyRestServerParameters() {
+        final RestServerParameters restServerParameters = commonTestData.getRestServerParameters(true);
+        final Map<String, ReceptionHandlerParameters> receptionHandlerParameters =
+                commonTestData.getReceptionHandlerParameters(false);
+
+        final DistributionParameterGroup distributionParameters = new DistributionParameterGroup(
+                CommonTestData.DISTRIBUTION_GROUP_NAME, restServerParameters, receptionHandlerParameters);
+        final GroupValidationResult validationResult = distributionParameters.validate();
+        assertFalse(validationResult.isValid());
+        assertTrue(validationResult.getResult()
+                .contains("\"org.onap.policy.distribution.main.parameters.RestServerParameters\" INVALID, "
+                        + "parameter group has status INVALID"));
+    }
 }
diff --git a/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterHandler.java b/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterHandler.java
index 79b12243..69ff0f14 100644
--- a/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterHandler.java
+++ b/main/src/test/java/org/onap/policy/distribution/main/parameters/TestDistributionParameterHandler.java
@@ -357,4 +357,72 @@ public class TestDistributionParameterHandler {
             assertTrue(e.getMessage().contains("policy forwarder class not found in classpath"));
         }
     }
+
+    @Test
+    public void testDistributionParameterGroup_InvalidRestServerHost() throws PolicyDistributionException {
+        final String[] distributionConfigParameters =
+                { "-c", "parameters/DistributionConfigParameters_InvalidRestServerHost.json" };
+
+        final DistributionCommandLineArguments arguments = new DistributionCommandLineArguments();
+        arguments.parse(distributionConfigParameters);
+
+        try {
+            new DistributionParameterHandler().getParameters(arguments);
+            fail("test should throw an exception here");
+        } catch (final Exception e) {
+            assertTrue(e.getMessage().contains(
+                    "must be a non-blank string containing hostname/ipaddress of the distribution rest server"));
+        }
+    }
+
+    @Test
+    public void testDistributionParameterGroup_InvalidRestServerPort() throws PolicyDistributionException {
+        final String[] distributionConfigParameters =
+                { "-c", "parameters/DistributionConfigParameters_InvalidRestServerPort.json" };
+
+        final DistributionCommandLineArguments arguments = new DistributionCommandLineArguments();
+        arguments.parse(distributionConfigParameters);
+
+        try {
+            new DistributionParameterHandler().getParameters(arguments);
+            fail("test should throw an exception here");
+        } catch (final Exception e) {
+            assertTrue(e.getMessage()
+                    .contains("must be a positive integer containing port of the distribution rest server"));
+        }
+    }
+
+    @Test
+    public void testDistributionParameterGroup_InvalidRestServerUser() throws PolicyDistributionException {
+        final String[] distributionConfigParameters =
+                { "-c", "parameters/DistributionConfigParameters_InvalidRestServerUser.json" };
+
+        final DistributionCommandLineArguments arguments = new DistributionCommandLineArguments();
+        arguments.parse(distributionConfigParameters);
+
+        try {
+            new DistributionParameterHandler().getParameters(arguments);
+            fail("test should throw an exception here");
+        } catch (final Exception e) {
+            assertTrue(e.getMessage().contains(
+                    "must be a non-blank string containing userName for distribution rest server credentials"));
+        }
+    }
+
+    @Test
+    public void testDistributionParameterGroup_InvalidRestServerPassword() throws PolicyDistributionException {
+        final String[] distributionConfigParameters =
+                { "-c", "parameters/DistributionConfigParameters_InvalidRestServerPassword.json" };
+
+        final DistributionCommandLineArguments arguments = new DistributionCommandLineArguments();
+        arguments.parse(distributionConfigParameters);
+
+        try {
+            new DistributionParameterHandler().getParameters(arguments);
+            fail("test should throw an exception here");
+        } catch (final Exception e) {
+            assertTrue(e.getMessage().contains(
+                    "must be a non-blank string containing password for distribution rest server credentials"));
+        }
+    }
 }
diff --git a/main/src/test/java/org/onap/policy/distribution/main/rest/TestDistributionRestServer.java b/main/src/test/java/org/onap/policy/distribution/main/rest/TestDistributionRestServer.java
new file mode 100644
index 00000000..df585574
--- /dev/null
+++ b/main/src/test/java/org/onap/policy/distribution/main/rest/TestDistributionRestServer.java
@@ -0,0 +1,116 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.distribution.main.rest;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import javax.ws.rs.client.Client;
+import javax.ws.rs.client.ClientBuilder;
+import javax.ws.rs.client.Invocation;
+import javax.ws.rs.client.WebTarget;
+import javax.ws.rs.core.MediaType;
+
+import org.glassfish.jersey.client.ClientConfig;
+import org.glassfish.jersey.client.authentication.HttpAuthenticationFeature;
+import org.junit.Test;
+import org.onap.policy.common.endpoints.report.HealthCheckReport;
+import org.onap.policy.distribution.main.PolicyDistributionException;
+import org.onap.policy.distribution.main.parameters.CommonTestData;
+import org.onap.policy.distribution.main.parameters.RestServerParameters;
+import org.onap.policy.distribution.main.startstop.Main;
+
+/**
+ * Class to perform unit test of HealthCheckMonitor.
+ *
+ * @author Ram Krishna Verma (ram.krishna.verma@ericsson.com)
+ */
+public class TestDistributionRestServer {
+
+    private static final String NOT_ALIVE = "not alive";
+    private static final String ALIVE = "alive";
+    private static final String SELF = "self";
+    private static final String NAME = "Policy SSD";
+
+    @Test
+    public void testHealthCheckSuccess() throws PolicyDistributionException, InterruptedException {
+        final String reportString = "Report [name=Policy SSD, url=self, healthy=true, code=200, message=alive]";
+        final Main main = startDistributionService();
+        final HealthCheckReport report = performHealthCheck();
+        validateReport(NAME, SELF, true, 200, ALIVE, reportString, report);
+        stopDistributionService(main);
+    }
+
+    @Test
+    public void testHealthCheckFailure() throws InterruptedException {
+        final String reportString = "Report [name=Policy SSD, url=self, healthy=false, code=500, message=not alive]";
+        final RestServerParameters restServerParams = new CommonTestData().getRestServerParameters(false);
+        restServerParams.setName(CommonTestData.DISTRIBUTION_GROUP_NAME);
+        final DistributionRestServer restServer = new DistributionRestServer(restServerParams);
+        restServer.start();
+        final HealthCheckReport report = performHealthCheck();
+        validateReport(NAME, SELF, false, 500, NOT_ALIVE, reportString, report);
+        assertTrue(restServer.isAlive());
+        assertTrue(restServer.toString().startsWith("DistributionRestServer [servers="));
+        restServer.shutdown();
+    }
+
+    private Main startDistributionService() {
+        final String[] distributionConfigParameters = { "-c", "parameters/DistributionConfigParameters.json" };
+        return new Main(distributionConfigParameters);
+    }
+
+    private void stopDistributionService(final Main main) throws PolicyDistributionException {
+        main.shutdown();
+    }
+
+    private HealthCheckReport performHealthCheck() throws InterruptedException {
+        HealthCheckReport response;
+        final ClientConfig clientConfig = new ClientConfig();
+
+        final HttpAuthenticationFeature feature = HttpAuthenticationFeature.basic("healthcheck", "zb!XztG34");
+        clientConfig.register(feature);
+
+        final Client client = ClientBuilder.newClient(clientConfig);
+        final WebTarget webTarget = client.target("http://localhost:6969/healthcheck");
+
+        final Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_JSON);
+        try {
+            response = invocationBuilder.get(HealthCheckReport.class);
+        } catch (final Exception exp) {
+            // may be the server is not started yet. Wait for couple of seconds and retry.
+            Thread.sleep(2000);
+            response = invocationBuilder.get(HealthCheckReport.class);
+        }
+
+        return response;
+    }
+
+    private void validateReport(final String name, final String url, final boolean healthy, final int code,
+            final String message, final String reportString, final HealthCheckReport report) {
+        assertEquals(name, report.getName());
+        assertEquals(url, report.getUrl());
+        assertEquals(healthy, report.isHealthy());
+        assertEquals(code, report.getCode());
+        assertEquals(message, report.getMessage());
+        assertEquals(reportString, report.toString());
+    }
+}
diff --git a/main/src/test/java/org/onap/policy/distribution/main/startstop/TestDistributionActivator.java b/main/src/test/java/org/onap/policy/distribution/main/startstop/TestDistributionActivator.java
index 6d1f83bf..25133cfe 100644
--- a/main/src/test/java/org/onap/policy/distribution/main/startstop/TestDistributionActivator.java
+++ b/main/src/test/java/org/onap/policy/distribution/main/startstop/TestDistributionActivator.java
@@ -60,6 +60,6 @@ public class TestDistributionActivator {
                 activator.getParameterGroup().getReceptionHandlerParameters()
                         .get(CommonTestData.SDC_RECEPTION_HANDLER_KEY).getPluginHandlerParameters()
                         .getPolicyForwarders().get(CommonTestData.PAP_ENGINE_FORWARDER_KEY).getForwarderType());
-        activator.deregisterToParameterService(parGroup);
+        activator.terminate();
     }
 }