/*
* Copyright 2012 Netflix, 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.netflix.exhibitor.servlet;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.io.Closeables;
import com.google.common.io.Resources;
import com.netflix.exhibitor.core.Exhibitor;
import com.netflix.exhibitor.standalone.ExhibitorCLI;
import com.netflix.exhibitor.standalone.ExhibitorCreator;
import com.netflix.exhibitor.standalone.ExhibitorCreatorExit;
import com.netflix.exhibitor.standalone.MissingConfigurationTypeException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.Properties;
public class ExhibitorServletContextListener implements ServletContextListener
{
private final Logger log = LoggerFactory.getLogger(getClass());
private volatile Exhibitor exhibitor;
private volatile ExhibitorCreator exhibitorCreator;
private static final String OUR_PREFIX = "exhibitor-";
private static final String EXHIBITOR_PROPERTIES = "exhibitor.properties";
@Override
public void contextInitialized(ServletContextEvent event)
{
Map<String, String> argsBuilder = makeArgsBuilder();
try
{
exhibitorCreator = new ExhibitorCreator(toArgsArray(argsBuilder));
exhibitor = new Exhibitor(exhibitorCreator.getConfigProvider(), null, exhibitorCreator.getBackupProvider(), exhibitorCreator.getBuilder().build());
exhibitor.start();
event.getServletContext().setAttribute(ExhibitorServletContextListener.class.getName(), exhibitor);
}
catch ( MissingConfigurationTypeException exit )
{
log.error("Configuration type (" + OUR_PREFIX + ExhibitorCLI.CONFIG_TYPE + ") must be specified");
exit.getCli().logHelp(OUR_PREFIX);
throw new RuntimeException(exit);
}
catch ( ExhibitorCreatorExit exit )
{
if ( exit.getError() != null )
{
log.error(exit.getError());
}
exit.getCli().logHelp(OUR_PREFIX);
throw new RuntimeException(exit);
}
catch ( Exception e )
{
log.error("Trying to create Exhibitor", e);
throw new RuntimeException(e);
}
}
@Override
public void contextDestroyed(ServletContextEvent event)
{
if ( exhibitor != null )
{
Closeables.closeQuietly(exhibitor);
exhibitor = null;
}
if ( exhibitorCreator != null )
{
for ( Closeable closeable : exhibitorCreator.getCloseables() )
{
Closeables.closeQuietly(closeable);
}
}
}
private String[] toArgsArray(Map<String, String> argsBuilder)
{
List<String> args = Lists.newArrayList();
for ( Map.Entry<String, String> entry : argsBuilder.entrySet() )
{
args.add(entry.getKey());
args.add(entry.getValue());
}
return args.toArray(new String[args.size()]);
}
private Map<String, String> makeArgsBuilder()
{
Map<String, String> argsBuilder = Maps.newHashMap();
try
{
URL resource = Resources.getResource(EXHIBITOR_PROPERTIES);
InputStream stream = resource.openStream();
try
{
Properties properties = new Properties(System.getProperties());
properties.load(stream);
applyProperties(argsBuilder, properties);
}
finally
{
Closeables.closeQuietly(stream);
}
}
catch ( IllegalArgumentException e )
{
log.warn("Could not find " + EXHIBITOR_PROPERTIES);
}
catch ( IOException e )
{
log.error("Could not load " + EXHIBITOR_PROPERTIES, e);
}
applyProperties(argsBuilder, System.getProperties());
return argsBuilder;
}
private void applyProperties(Map<String, String> argsBuilder, Properties properties)
{
Enumeration parameterNames = properties.propertyNames();
while ( parameterNames.hasMoreElements() )
{
String name = String.valueOf(parameterNames.nextElement());
if ( name.startsWith(OUR_PREFIX) )
{
String value = properties.getProperty(name);
String argName = name.substring(OUR_PREFIX.length());
argsBuilder.put("-" + argName, value);
log.info(String.format("Setting property %s=%s", argName, value));
}
}
}
}