1 files changed, 219 insertions, 0 deletions
diff --git a/catalog-fe/src/main/java/org/openecomp/sdc/fe/servlets/HealthCheckService.java b/catalog-fe/src/main/java/org/openecomp/sdc/fe/servlets/HealthCheckService.java
new file mode 100644
index 0000000000..338e8d4c01
--- /dev/null
+++ b/catalog-fe/src/main/java/org/openecomp/sdc/fe/servlets/HealthCheckService.java
@@ -0,0 +1,219 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * SDC
+ * ================================================================================
+ * Copyright (C) 2017 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.openecomp.sdc.fe.servlets;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+
+import javax.servlet.ServletContext;
+import javax.ws.rs.core.Response;
+
+import org.apache.http.client.config.RequestConfig;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.http.util.EntityUtils;
+import org.openecomp.sdc.common.api.Constants;
+import org.openecomp.sdc.common.api.HealthCheckInfo;
+import org.openecomp.sdc.common.api.HealthCheckInfo.HealthCheckComponent;
+import org.openecomp.sdc.common.api.HealthCheckInfo.HealthCheckStatus;
+import org.openecomp.sdc.common.api.HealthCheckWrapper;
+import org.openecomp.sdc.common.config.EcompErrorName;
+import org.openecomp.sdc.common.impl.ExternalConfiguration;
+import org.openecomp.sdc.fe.config.Configuration;
+import org.openecomp.sdc.fe.config.ConfigurationManager;
+import org.openecomp.sdc.fe.config.FeEcompErrorManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.reflect.TypeToken;
+
+public class HealthCheckService {
+
+	private class HealthStatus {
+		public String body;
+		public int statusCode;
+
+		public HealthStatus(int code, String body) {
+			this.body = body;
+			this.statusCode = code;
+		}
+	}
+
+	private static final String URL = "%s://%s:%s/sdc2/rest/healthCheck";
+	private static Logger healthLogger = LoggerFactory.getLogger("asdc.fe.healthcheck");
+	private static Logger log = LoggerFactory.getLogger(HealthCheckService.class.getName());
+
+	private HealthStatus lastHealthStatus = new HealthStatus(500, "{}");
+
+	private class HealthCheckScheduledTask implements Runnable {
+		@Override
+		public void run() {
+			healthLogger.trace("Executing FE Health Check Task - Start");
+			HealthStatus currentHealth = checkHealth();
+			int currentHealthStatus = currentHealth.statusCode;
+			healthLogger.trace("Executing FE Health Check Task - Status = {}", currentHealthStatus);
+
+			// In case health status was changed, issue alarm/recovery
+			if (currentHealthStatus != lastHealthStatus.statusCode) {
+				log.trace("FE Health State Changed to {}. Issuing alarm / recovery alarm...", currentHealthStatus);
+				logFeAlarm(currentHealthStatus);
+			}
+
+			// Anyway, update latest response
+			lastHealthStatus = currentHealth;
+		}
+	}
+
+	/**
+	 * This executor will execute the health check task.
+	 */
+	ScheduledExecutorService healthCheckExecutor = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
+		@Override
+		public Thread newThread(Runnable r) {
+			return new Thread(r, "FE-Health-Check-Thread");
+		}
+	});
+	private ServletContext context;
+
+	public HealthCheckService(ServletContext context) {
+		this.context = context;
+	}
+
+	public void start(int interval) {
+		this.healthCheckExecutor.scheduleAtFixedRate(new HealthCheckScheduledTask(), 0, interval, TimeUnit.SECONDS);
+	}
+
+	/**
+	 * To be used by the HealthCheckServlet
+	 * 
+	 * @return
+	 */
+	public Response getFeHealth() {
+		return this.buildResponse(lastHealthStatus.statusCode, lastHealthStatus.body);
+	}
+
+	private HealthStatus checkHealth() {
+		CloseableHttpClient httpClient = null;
+		try {
+			Gson gson = new GsonBuilder().setPrettyPrinting().create();
+			Configuration config = ((ConfigurationManager) context.getAttribute(Constants.CONFIGURATION_MANAGER_ATTR))
+					.getConfiguration();
+			String redirectedUrl = String.format(URL, config.getBeProtocol(), config.getBeHost(),
+					config.getBeHttpPort());
+			httpClient = getHttpClient(config);
+			HttpGet httpGet = new HttpGet(redirectedUrl);
+			CloseableHttpResponse beResponse;
+			int beStatus;
+			String feAggHealthCheck;
+			try {
+				beResponse = httpClient.execute(httpGet);
+				beStatus = beResponse.getStatusLine().getStatusCode();
+				String beJsonResponse = EntityUtils.toString(beResponse.getEntity());
+				feAggHealthCheck = getFeHealthCheckInfos(gson, beJsonResponse);
+			} catch (Exception e) {
+				log.error("Health Check error when trying to connect to BE", e);
+				String beDowneResponse = gson.toJson(getBeDownCheckInfos());
+				return new HealthStatus(500, beDowneResponse);
+			}
+			return new HealthStatus(beStatus, feAggHealthCheck);
+		} catch (Exception e) {
+			FeEcompErrorManager.getInstance().processEcompError(EcompErrorName.FeHealthCheckGeneralError, "Unexpected FE Health check error");
+			FeEcompErrorManager.getInstance().logFeHealthCheckGeneralError("Unexpected FE Health check error");
+			log.error("Unexpected FE health check error {}", e.getMessage());
+			return new HealthStatus(500, e.getMessage());
+		} finally {
+			if (httpClient != null) {
+				try {
+					httpClient.close();
+				} catch (IOException e) {
+				}
+			}
+		}
+	}
+
+	private Response buildResponse(int status, String jsonResponse) {
+		healthLogger.trace("FE and BE health check status: {}", jsonResponse);
+		return Response.status(status).entity(jsonResponse).build();
+	}
+
+	private void logFeAlarm(int lastFeStatus) {
+
+		switch (lastFeStatus) {
+		case 200:
+			FeEcompErrorManager.getInstance().processEcompError(EcompErrorName.FeHealthCheckRecovery,
+					"FE Health Recovered");
+			FeEcompErrorManager.getInstance().logFeHealthCheckRecovery("FE Health Recovered");
+			break;
+		case 500:
+			FeEcompErrorManager.getInstance().processEcompError(EcompErrorName.FeHealthCheckConnectionError,
+					"Connection with ASDC-BE is probably down");
+			FeEcompErrorManager.getInstance().logFeHealthCheckError("Connection with ASDC-BE is probably down");
+			break;
+		default:
+			break;
+		}
+
+	}
+
+	private String getFeHealthCheckInfos(Gson gson, String responseString) {
+		Type wrapperType = new TypeToken<HealthCheckWrapper>() {
+		}.getType();
+		HealthCheckWrapper healthCheckWrapper = gson.fromJson(responseString, wrapperType);
+		String appVersion = ExternalConfiguration.getAppVersion();
+		String description = "OK";
+		healthCheckWrapper.getComponentsInfo()
+				.add(new HealthCheckInfo(HealthCheckComponent.FE, HealthCheckStatus.UP, appVersion, description));
+		return gson.toJson(healthCheckWrapper);
+	}
+
+	private HealthCheckWrapper getBeDownCheckInfos() {
+		List<HealthCheckInfo> healthCheckInfos = new ArrayList<HealthCheckInfo>();
+		healthCheckInfos.add(new HealthCheckInfo(HealthCheckComponent.FE, HealthCheckStatus.UP,
+				ExternalConfiguration.getAppVersion(), "OK"));
+		healthCheckInfos.add(new HealthCheckInfo(HealthCheckComponent.BE, HealthCheckStatus.DOWN, null, null));
+		healthCheckInfos.add(new HealthCheckInfo(HealthCheckComponent.ES, HealthCheckStatus.UNKNOWN, null, null));
+		healthCheckInfos.add(new HealthCheckInfo(HealthCheckComponent.TITAN, HealthCheckStatus.UNKNOWN, null, null));
+		healthCheckInfos.add(new HealthCheckInfo(HealthCheckComponent.DE, HealthCheckStatus.UNKNOWN, null, null));
+		HealthCheckWrapper hcWrapper = new HealthCheckWrapper(healthCheckInfos, "UNKNOWN", "UNKNOWN");
+		return hcWrapper;
+	}
+
+	private CloseableHttpClient getHttpClient(Configuration config) {
+		int timeout = 3000;
+		int socketTimeout = config.getHealthCheckSocketTimeoutInMs(5000);
+		RequestConfig.Builder requestBuilder = RequestConfig.custom();
+		requestBuilder.setConnectTimeout(timeout).setConnectionRequestTimeout(timeout).setSocketTimeout(socketTimeout);
+
+		HttpClientBuilder builder = HttpClientBuilder.create();
+		builder.setDefaultRequestConfig(requestBuilder.build());
+		return builder.build();
+	}
+}