org.graylog2.hipchatalarmcallback.callback.GraylogElasticSearchClient.java Source code

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Here is the source code for org.graylog2.hipchatalarmcallback.callback.GraylogElasticSearchClient.java

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/**
 * Copyright 2014 Markus Wuersch <markus@wuersch.net>
 *
 * This file is part of Graylog2.
 *
 * Graylog2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Graylog2 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Graylog2.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
package org.graylog2.hipchatalarmcallback.callback;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.URL;

import org.apache.log4j.Logger;

import com.mongodb.BasicDBList;
import com.mongodb.DBObject;
import com.mongodb.util.JSON;

/**
 * A simple elasticsearch client to get necessary information about a triggered Alarm. 
 * @author Markus Wuersch <markus@wuersch.net>
 */
public class GraylogElasticSearchClient {

    private static Logger LOG = Logger.getLogger(GraylogElasticSearchClient.class.getName());

    /**
     * Get the last GrayLog message in a stream. 
     * @param streamId The GrayLog2 stream id
     * @param graylogUrl The URL to your GrayLog instance. 
     * @param elasticSearchUrl   The URL of the elasticsearch instance. 
     * @return GraylogMessage object of the last message in the stream.
     */
    public GraylogMessage getLastMessageInStream(String streamId, String graylogUrl, String elasticSearchUrl) {

        GraylogMessage message = new GraylogMessage();

        Writer writer = null;
        try {
            // query elasticsearch for last message in stream
            URL url = new URL(elasticSearchUrl + "/_search");
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setDoOutput(true);
            conn.setRequestMethod("POST");

            writer = new OutputStreamWriter(conn.getOutputStream());
            writer.write("{\"query\": {\"term\": {\"streams\": \"" + streamId
                    + "\"}}, \"sort\":[{\"created_at\": \"desc\"}], \"size\":1}");
            writer.flush();

            if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {

                // read elasticsearch API response into StringBuilder
                BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                StringBuilder responseData = new StringBuilder();
                String line = null;
                while ((line = br.readLine()) != null) {
                    responseData.append(line);
                }
                // create JSON Object from elasticsearch result String
                DBObject json = (DBObject) JSON.parse(responseData.toString());
                DBObject hits = (DBObject) json.get("hits");
                BasicDBList hitsList = (BasicDBList) hits.get("hits");
                DBObject hit = (DBObject) hitsList.get(0);
                DBObject source = (DBObject) hit.get("_source");
                message.setLevel(((Integer) source.get("level")).intValue());

                String id = (String) hit.get("_id");
                // message content
                String text = (String) source.get("message");
                // append deep link to message on GrayLog2
                text = text + "\n" + graylogUrl + "/messages/" + id;
                message.setText(text);
            } else {
                LOG.error("unable to query elasticsearch. response code: " + conn.getResponseCode());
            }

        } catch (IOException e) {
            LOG.error("unable to query elasticsearch", e);
            message = null;
        } catch (RuntimeException rte) {
            LOG.error("unable to query elasticsearch", rte);
            message = null;
        } finally {
            if (writer != null) {
                try {
                    writer.close();
                } catch (IOException e) {
                }
            }
        }

        return message;
    }

}