/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.cassandra.locator;
import java.io.DataInputStream;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.File;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.URL;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.util.Map;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.db.SystemKeyspace;
import org.apache.cassandra.exceptions.ConfigurationException;
import org.apache.cassandra.gms.ApplicationState;
import org.apache.cassandra.gms.EndpointState;
import org.apache.cassandra.gms.Gossiper;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.cassandra.utils.JVMStabilityInspector;
/**
* {@code
* A snitch that assumes a Cloudstack Zone follows the typical convention
* <country>-<location>-<availability zone> and uses the country/location
* tuple as a datacenter and the availability zone as a rack
* }
*/
public class CloudstackSnitch extends AbstractNetworkTopologySnitch
{
protected static final Logger logger = LoggerFactory.getLogger(CloudstackSnitch.class);
protected static final String ZONE_NAME_QUERY_URI = "/latest/meta-data/availability-zone";
private Map<InetAddress, Map<String, String>> savedEndpoints;
private static final String DEFAULT_DC = "UNKNOWN-DC";
private static final String DEFAULT_RACK = "UNKNOWN-RACK";
private static final String[] LEASE_FILES =
{
"file:///var/lib/dhcp/dhclient.eth0.leases",
"file:///var/lib/dhclient/dhclient.eth0.leases"
};
protected String csZoneDc;
protected String csZoneRack;
public CloudstackSnitch() throws IOException, ConfigurationException
{
String endpoint = csMetadataEndpoint();
String zone = csQueryMetadata(endpoint + ZONE_NAME_QUERY_URI);
String zone_parts[] = zone.split("-");
if (zone_parts.length != 3)
{
throw new ConfigurationException("CloudstackSnitch cannot handle invalid zone format: " + zone);
}
csZoneDc = zone_parts[0] + "-" + zone_parts[1];
csZoneRack = zone_parts[2];
}
public String getRack(InetAddress endpoint)
{
if (endpoint.equals(FBUtilities.getBroadcastAddress()))
return csZoneRack;
EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
if (state == null || state.getApplicationState(ApplicationState.RACK) == null)
{
if (savedEndpoints == null)
savedEndpoints = SystemKeyspace.loadDcRackInfo();
if (savedEndpoints.containsKey(endpoint))
return savedEndpoints.get(endpoint).get("rack");
return DEFAULT_RACK;
}
return state.getApplicationState(ApplicationState.RACK).value;
}
public String getDatacenter(InetAddress endpoint)
{
if (endpoint.equals(FBUtilities.getBroadcastAddress()))
return csZoneDc;
EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
if (state == null || state.getApplicationState(ApplicationState.DC) == null)
{
if (savedEndpoints == null)
savedEndpoints = SystemKeyspace.loadDcRackInfo();
if (savedEndpoints.containsKey(endpoint))
return savedEndpoints.get(endpoint).get("data_center");
return DEFAULT_DC;
}
return state.getApplicationState(ApplicationState.DC).value;
}
String csQueryMetadata(String url) throws ConfigurationException, IOException
{
HttpURLConnection conn = null;
DataInputStream is = null;
try
{
conn = (HttpURLConnection) new URL(url).openConnection();
}
catch (Exception e)
{
throw new ConfigurationException("CloudstackSnitch cannot query wrong metadata URL: " + url);
}
try
{
conn.setRequestMethod("GET");
if (conn.getResponseCode() != 200)
{
throw new ConfigurationException("CloudstackSnitch was unable to query metadata.");
}
int cl = conn.getContentLength();
byte[] b = new byte[cl];
is = new DataInputStream(new BufferedInputStream(conn.getInputStream()));
is.readFully(b);
return new String(b, StandardCharsets.UTF_8);
}
finally
{
FileUtils.close(is);
conn.disconnect();
}
}
String csMetadataEndpoint() throws ConfigurationException
{
for (String lease_uri: LEASE_FILES)
{
try
{
File lease_file = new File(new URI(lease_uri));
if (lease_file.exists())
{
return csEndpointFromLease(lease_file);
}
}
catch (Exception e)
{
JVMStabilityInspector.inspectThrowable(e);
continue;
}
}
throw new ConfigurationException("No valid DHCP lease file could be found.");
}
String csEndpointFromLease(File lease) throws ConfigurationException
{
String line;
String endpoint = null;
Pattern identifierPattern = Pattern.compile("^[ \t]*option dhcp-server-identifier (.*);$");
try (BufferedReader reader = new BufferedReader(new FileReader(lease)))
{
while ((line = reader.readLine()) != null)
{
Matcher matcher = identifierPattern.matcher(line);
if (matcher.find())
{
endpoint = matcher.group(1);
break;
}
}
}
catch (Exception e)
{
throw new ConfigurationException("CloudstackSnitch cannot access lease file.");
}
if (endpoint == null)
{
throw new ConfigurationException("No metadata server could be found in lease file.");
}
return "http://" + endpoint;
}
}