com.facebook.tsdb.tsdash.server.TsdbServlet.java Source code

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Here is the source code for com.facebook.tsdb.tsdash.server.TsdbServlet.java

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/*
 * Copyright 2011 Facebook, Inc.
 *
 * 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.
 */
package com.facebook.tsdb.tsdash.server;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Properties;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
import org.json.simple.JSONObject;

import com.facebook.tsdb.tsdash.server.data.hbase.HBaseConnection;
import com.google.common.base.Objects;
import com.google.common.base.Strings;

public class TsdbServlet extends HttpServlet {

    protected static Logger logger = Logger.getLogger("com.facebook.tsdb.services");

    private static final long serialVersionUID = 1L;
    public static final String PROPERTIES_FILE = "conf/tsdash.properties";
    public static final String LOG4J_PROPERTIES_FILE = "conf/log4j.properties";

    public static final String URL_PATTERN_PARAM = "plot.tsdash.urlpattern";
    public static final String DEFAULT_URL_PATTERN = "http://%h:%p/plots/%f";
    public static final int DEFAULT_PLOT_PORT = 8090;

    public static final String PLOTS_DIR_PARAM = "plot.tsdash.dir";
    public static final String DEFAULT_PLOTS_DIR = "/tmp";

    public static final String SERVE_IMAGES_LOCALLY_PARAM = "plot.tsdash.serveImagesLocally";
    private static final String DEFAULT_SERVE_IMAGES_LOCALLY = "false";

    public static String plotsDir = DEFAULT_PLOTS_DIR;
    private static String URLPattern = DEFAULT_URL_PATTERN;
    private static boolean serveImagesLocally = Boolean.parseBoolean(DEFAULT_SERVE_IMAGES_LOCALLY);

    private String hostname = null;

    @Override
    public final void init(ServletConfig config) throws ServletException {
        String tsdashFile = config.getInitParameter("TSDASH_PROPERTIES_FILE");
        tsdashFile = Objects.firstNonNull(Strings.emptyToNull(tsdashFile), PROPERTIES_FILE);

        String log4jFile = config.getInitParameter("LOG4J_PROPERTIES_FILE");
        log4jFile = Objects.firstNonNull(Strings.emptyToNull(log4jFile), LOG4J_PROPERTIES_FILE);

        try {
            PropertyConfigurator.configure(log4jFile);

            Properties tsdbConf = new Properties();
            tsdbConf.load(new FileInputStream(tsdashFile));

            HBaseConnection.configure(tsdbConf);

            URLPattern = tsdbConf.getProperty(URL_PATTERN_PARAM, DEFAULT_URL_PATTERN);
            logger.info("URL pattern: " + URLPattern);
            plotsDir = tsdbConf.getProperty(PLOTS_DIR_PARAM, DEFAULT_PLOTS_DIR);
            logger.info("Plots are being written to: " + plotsDir);

            serveImagesLocally = Boolean
                    .parseBoolean(tsdbConf.getProperty(SERVE_IMAGES_LOCALLY_PARAM, DEFAULT_SERVE_IMAGES_LOCALLY));

            if (serveImagesLocally) {
                logger.info("Serving plot images locally.");
            }
        } catch (IOException e) {
            throw new ServletException("Unable to load TsDash properties file(s).", e);
        }
    }

    protected String generatePlotURL(final String filenamePath, final HttpServletRequest request)
            throws UnknownHostException {
        final File plot = new File(filenamePath);

        if (serveImagesLocally) {
            return new StringBuilder().append(request.getContextPath()).append("/plotimg/") // URL pattern bound to PlotImageEndpoint
                    .append(plot.getName()).toString();
        } else {
            if (hostname == null) {
                hostname = InetAddress.getLocalHost().getHostName();
            }
            String URL = URLPattern.replace("%h", hostname);
            URL = URL.replace("%p", "" + DEFAULT_PLOT_PORT);
            URL = URL.replace("%f", plot.getName());
            return URL;
        }
    }

    @SuppressWarnings("unchecked")
    protected String getErrorResponse(Throwable e) {
        JSONObject errObj = new JSONObject();
        errObj.put("error", e.getMessage());
        StringWriter stackTrace = new StringWriter();
        e.printStackTrace(new PrintWriter(stackTrace));
        errObj.put("stacktrace", stackTrace.toString());
        return errObj.toJSONString();
    }

    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        response.sendError(HttpServletResponse.SC_BAD_REQUEST);
    }
}