-
/*-
* ========================LICENSE_START=================================
* O-RAN-SC
* %%
- * Copyright (C) 2019 Nordix Foundation
+ * 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.
package org.oransc.policyagent.dmaap;
+import com.google.common.collect.Iterables;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.oransc.policyagent.clients.AsyncRestClient;
+import org.oransc.policyagent.configuration.ApplicationConfig;
+import org.oransc.policyagent.exceptions.ServiceException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+
/**
- * The Dmaap consumer which has the base methods to be implemented by any class which implements this interface
+ * The class fetches incoming requests from DMAAP. It uses the timeout parameter
+ * that lets the MessageRouter keep the connection with the Kafka open until
+ * requests are sent in.
*
+ * <p>
+ * this service will regularly check the configuration and start polling DMaaP
+ * if the configuration is added. If the DMaaP configuration is removed, then
+ * the service will stop polling and resume checking for configuration.
+ *
+ * <p>
+ * Each received request is processed by {@link DmaapMessageHandler}.
*/
-public interface DmaapMessageConsumer {
+@Component
+public class DmaapMessageConsumer {
- /**
- * The init method creates the MRConsumer with the properties passed from the Application Config
- *
- * @param properties
- */
- public void init();
+ protected static final Duration TIME_BETWEEN_DMAAP_RETRIES = Duration.ofSeconds(10);
- /**
- * This method process the message and call the respective Controller
- *
- * @param msg
- * @throws Exception
- */
- public abstract void processMsg(String msg) throws Exception;
+ private static final Logger logger = LoggerFactory.getLogger(DmaapMessageConsumer.class);
+
+ private final ApplicationConfig applicationConfig;
+
+ private DmaapMessageHandler dmaapMessageHandler = null;
+
+ @Value("${server.http-port}")
+ private int localServerHttpPort;
+
+ @Autowired
+ public DmaapMessageConsumer(ApplicationConfig applicationConfig) {
+ this.applicationConfig = applicationConfig;
+ }
/**
- * To check whether the DMAAP Listner is alive
+ * Starts the consumer. If there is a DMaaP configuration, it will start polling
+ * for messages. Otherwise it will check regularly for the configuration.
*
- * @return boolean
+ * @return the running thread, for test purposes.
*/
- public boolean isAlive();
+ public Thread start() {
+ Thread thread = new Thread(this::messageHandlingLoop);
+ thread.start();
+ return thread;
+ }
- /**
- * To Stop the DMAAP Listener
- */
- public void stopConsumer();
+ private void messageHandlingLoop() {
+ while (!isStopped()) {
+ try {
+ if (isDmaapConfigured()) {
+ Iterable<String> dmaapMsgs = fetchAllMessages();
+ if (dmaapMsgs != null && Iterables.size(dmaapMsgs) > 0) {
+ logger.debug("Fetched all the messages from DMAAP and will start to process the messages");
+ for (String msg : dmaapMsgs) {
+ processMsg(msg);
+ }
+ }
+ } else {
+ sleep(TIME_BETWEEN_DMAAP_RETRIES); // wait for configuration
+ }
+ } catch (Exception e) {
+ logger.warn("{}", e.getMessage());
+ sleep(TIME_BETWEEN_DMAAP_RETRIES);
+ }
+ }
+ }
- /**
- * It's a infinite loop run every configured seconds to fetch the message from DMAAP. This method can be stop by
- * setting the alive flag to false
- */
- public void run();
+ protected boolean isStopped() {
+ return false;
+ }
+
+ protected boolean isDmaapConfigured() {
+ String producerTopicUrl = applicationConfig.getDmaapProducerTopicUrl();
+ String consumerTopicUrl = applicationConfig.getDmaapConsumerTopicUrl();
+ return (!producerTopicUrl.isEmpty() && !consumerTopicUrl.isEmpty());
+ }
+
+ private static List<String> parseMessages(String jsonString) {
+ JsonArray arrayOfMessages = JsonParser.parseString(jsonString).getAsJsonArray();
+ List<String> result = new ArrayList<>();
+ for (JsonElement element : arrayOfMessages) {
+ if (element.isJsonPrimitive()) {
+ result.add(element.getAsString());
+ } else {
+ String messageAsString = element.toString();
+ result.add(messageAsString);
+ }
+ }
+ return result;
+ }
+
+ protected Iterable<String> fetchAllMessages() throws ServiceException {
+ String topicUrl = this.applicationConfig.getDmaapConsumerTopicUrl();
+ AsyncRestClient consumer = getMessageRouterConsumer();
+ ResponseEntity<String> response = consumer.getForEntity(topicUrl).block();
+ logger.debug("DMaaP consumer received {} : {}", response.getStatusCode(), response.getBody());
+ if (response.getStatusCode().is2xxSuccessful()) {
+ return parseMessages(response.getBody());
+ } else {
+ throw new ServiceException("Cannot fetch because of Error respons: " + response.getStatusCode().toString()
+ + " " + response.getBody());
+ }
+ }
+
+ private void processMsg(String msg) {
+ logger.debug("Message Reveived from DMAAP : {}", msg);
+ getDmaapMessageHandler().handleDmaapMsg(msg);
+ }
+
+ protected DmaapMessageHandler getDmaapMessageHandler() {
+ if (this.dmaapMessageHandler == null) {
+ String agentBaseUrl = "http://localhost:" + this.localServerHttpPort;
+ AsyncRestClient agentClient =
+ new AsyncRestClient(agentBaseUrl, this.applicationConfig.getWebClientConfig());
+ AsyncRestClient producer = new AsyncRestClient(this.applicationConfig.getDmaapProducerTopicUrl(),
+ this.applicationConfig.getWebClientConfig());
+ this.dmaapMessageHandler = new DmaapMessageHandler(producer, agentClient);
+ }
+ return this.dmaapMessageHandler;
+ }
+
+ protected void sleep(Duration duration) {
+ try {
+ Thread.sleep(duration.toMillis());
+ } catch (Exception e) {
+ logger.error("Failed to put the thread to sleep", e);
+ }
+ }
+
+ protected AsyncRestClient getMessageRouterConsumer() {
+ return new AsyncRestClient("", this.applicationConfig.getWebClientConfig());
+ }
}