com.netflix.eureka.util.EIPManager Maven / Gradle / Ivy
/*
* 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.eureka.util;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.auth.InstanceProfileCredentialsProvider;
import com.amazonaws.services.ec2.AmazonEC2;
import com.amazonaws.services.ec2.AmazonEC2Client;
import com.amazonaws.services.ec2.model.AssociateAddressRequest;
import com.amazonaws.services.ec2.model.DescribeAddressesRequest;
import com.amazonaws.services.ec2.model.DescribeAddressesResult;
import com.amazonaws.services.ec2.model.DisassociateAddressRequest;
import com.netflix.appinfo.AmazonInfo;
import com.netflix.appinfo.AmazonInfo.MetaDataKey;
import com.netflix.appinfo.ApplicationInfoManager;
import com.netflix.appinfo.DataCenterInfo.Name;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.discovery.DiscoveryManager;
import com.netflix.eureka.EurekaServerConfig;
import com.netflix.eureka.EurekaServerConfigurationManager;
import com.netflix.eureka.PeerAwareInstanceRegistry;
import com.netflix.eureka.cluster.PeerEurekaNode;
import com.netflix.servo.monitor.Monitors;
/**
* An AWS specific elastic ip binding utility for binding eureka
* servers for a well known IP address.
*
*
* Eureka clients talk to Eureka servers bound with well known
* IP addresses since that is the most reliable mechanism to
* discover the Eureka servers. When Eureka servers come up they bind
* themselves to a well known elastic ip
*
*
*
* This binding mechanism gravitates towards one eureka server per zone for
* resilience.Atleast one elastic ip should be slotted for each eureka server in
* a zone. If more than eureka server is launched per zone and there are not
* enough elastic ips slotted, the server tries to pick a free EIP slotted for other
* zones and if it still cannot find a free EIP, waits and keeps trying.
*
*
* @author Karthik Ranganathan, Greg Kim
*
*/
public class EIPManager {
private static final int HEARTBEAT_RETRY_INTERVAL_MS = 300;
private static final int NO_HEARTBEAT_RETRIES = 3;
private static final String US_EAST_1 = "us-east-1";
private static final Logger logger = LoggerFactory
.getLogger(EIPManager.class);
private EurekaServerConfig eurekaConfig = EurekaServerConfigurationManager
.getInstance().getConfiguration();
private static final EIPManager s_instance = new EIPManager();
public static EIPManager getInstance() {
return s_instance;
}
private EIPManager() {
try {
Monitors.registerObject(this);
} catch (Throwable e) {
logger.warn(
"Cannot register the JMX monitor for the InstanceRegistry :",
e);
}
}
/**
* Checks if an EIP is already bound to the instance
* @return true if an EIP is bound, false otherwise
*/
public boolean isEIPBound() {
InstanceInfo myInfo = ApplicationInfoManager.getInstance().getInfo();
String myInstanceId = ((AmazonInfo) myInfo.getDataCenterInfo())
.get(MetaDataKey.instanceId);
String myZone = ((AmazonInfo) myInfo.getDataCenterInfo())
.get(MetaDataKey.availabilityZone);
String myPublicIP = ((AmazonInfo) myInfo.getDataCenterInfo())
.get(MetaDataKey.publicIpv4);
Collection candidateEIPs = getCandidateEIPs(myInstanceId,
myZone);
for (String eipEntry : candidateEIPs) {
if (eipEntry.equals(myPublicIP)) {
logger.info(
"My instance {} seems to be already associated with the public ip {}",
myInstanceId, myPublicIP);
return true;
}
}
return false;
}
/**
* Checks if an EIP is bound and optionally binds the EIP.
*
* The list of EIPs are arranged with the EIPs allocated in the zone first
* followed by other EIPs.
*
* If an EIP is already bound to this instance this method simply returns. Otherwise, this method tries to find
* an unused EIP based on information from AWS. If it cannot find any unused EIP this method, it will be retried
* for a specified interval.
*
* One of the following scenarios can happen here :
*
* 1) If the instance is already bound to an EIP as deemed by AWS, no action is taken.
* 2) If an EIP is already bound to another instance as deemed by AWS, that EIP is skipped.
* 3) If an EIP is not already bound to an instance and if this instance is not bound to an EIP, then
* the EIP is bound to this instance.
*
* @param shouldBind - indicates if the EIP should be bound if it is not already bound.
*
* @return true - if the EIP is bound, false otherwise.
*/
public void bindEIP( ) {
InstanceInfo myInfo = ApplicationInfoManager.getInstance().getInfo();
String myInstanceId = ((AmazonInfo) myInfo.getDataCenterInfo())
.get(MetaDataKey.instanceId);
String myZone = ((AmazonInfo) myInfo.getDataCenterInfo())
.get(MetaDataKey.availabilityZone);
String myPublicIP = ((AmazonInfo) myInfo.getDataCenterInfo())
.get(MetaDataKey.publicIpv4);
Collection candidateEIPs = getCandidateEIPs(myInstanceId,
myZone);
AmazonEC2 ec2Service = getEC2Service();
boolean isMyinstanceAssociatedWithEIP = false;
String selectedEIP = null;
for (String eipEntry : candidateEIPs) {
try {
String associatedInstanceId = null;
// Check with AWS, if this EIP is already been used by another
// instance
DescribeAddressesRequest describeAddressRequest = new DescribeAddressesRequest()
.withPublicIps(eipEntry);
DescribeAddressesResult result = ec2Service
.describeAddresses(describeAddressRequest);
if ((result.getAddresses() != null)
&& (!result.getAddresses().isEmpty())) {
associatedInstanceId = result.getAddresses().get(0)
.getInstanceId();
// This EIP is not used by any other instance, hence mark it for selection if it is not
// already marked.
if (((associatedInstanceId == null) || (associatedInstanceId
.isEmpty()))) {
if (selectedEIP == null) {
selectedEIP = eipEntry;
}
}
// This EIP is associated with an instance, check if this is the same as the current instance.
// If it is the same, stop searching for an EIP as this instance is already associated with an EIP
else if (isMyinstanceAssociatedWithEIP = (associatedInstanceId
.equals(myInstanceId))) {
selectedEIP = eipEntry;
break;
}
// The EIP is used by some other instance, hence skip it
else {
logger.warn(
"The selected EIP {} is associated with another instance {} according to AWS, hence skipping this",
eipEntry, associatedInstanceId);
continue;
}
}
} catch (Throwable t) {
logger.error("Failed to bind elastic IP: " + eipEntry + " to "
+ myInstanceId, t);
}
}
// Only bind if the EIP is already associated
if (!isMyinstanceAssociatedWithEIP) {
AssociateAddressRequest associateAddressRequest = new AssociateAddressRequest(
myInstanceId, selectedEIP);
ec2Service.associateAddress(associateAddressRequest);
logger.info("\n\n\nAssociated " + myInstanceId
+ " running in zone: " + myZone + " to elastic IP: "
+ selectedEIP);
}
logger.info(
"My instance {} seems to be already associated with the EIP {}",
myInstanceId, selectedEIP);
}
/**
* Unbind the EIP that this instance is associated with.
*/
public void unbindEIP() {
InstanceInfo myInfo = ApplicationInfoManager.getInstance().getInfo();
String myPublicIP = null;
if (myInfo != null
&& myInfo.getDataCenterInfo().getName() == Name.Amazon) {
myPublicIP = ((AmazonInfo) myInfo.getDataCenterInfo())
.get(MetaDataKey.publicIpv4);
try {
AmazonEC2 ec2Service = getEC2Service();
DisassociateAddressRequest dissociateRequest = new DisassociateAddressRequest()
.withPublicIp(myPublicIP);
ec2Service.disassociateAddress(dissociateRequest);
logger.info("Dissociated the EIP {} from this instance",
myPublicIP);
} catch (Throwable e) {
throw new RuntimeException("Cannot dissociate address"
+ myPublicIP + "from this instance", e);
}
}
}
/**
* Get the list of EIPs in the order of preference depending on instance zone
*
* @param myInstanceId
* the instance id for this instance
* @param myZone
* the zone where this instance is in
* @param myPublicIP
* the public ip of this instance
* @return Collection containing the list of available EIPs
*/
public Collection getCandidateEIPs(String myInstanceId, String myZone) {
if (myZone == null) {
myZone = "us-east-1d";
}
Collection eipCandidates = (DiscoveryManager.getInstance()
.getEurekaClientConfig().shouldUseDnsForFetchingServiceUrls() ? getEIPsForZoneFromDNS(myZone)
: getEIPsForZoneFromConfig(myZone));
if (eipCandidates == null || eipCandidates.size() == 0) {
throw new RuntimeException(
"Could not get any elastic ips from the EIP pool for zone :"
+ myZone);
}
return eipCandidates;
}
/**
* Return the @link {PeerEurekaNode} given the host name.
* @param instanceHostName - the host name for which the @link {PeerEurekaNode}.
* @return @link {PeerEurekaNode} object that represents this host name.
*/
private PeerEurekaNode getPeerEurekaNode(String instanceHostName) {
PeerEurekaNode replicaNode = null;
try {
for (PeerEurekaNode node : PeerAwareInstanceRegistry
.getInstance().getReplicaNodes()) {
if (new URL(node.getServiceUrl()).getHost()
.equalsIgnoreCase(instanceHostName)) {
replicaNode = node;
}
}
} catch (Throwable e) {
logger.error(
"Cannot get peer eureka node instance from instanceHostName for "
+ instanceHostName, replicaNode);
}
return replicaNode;
}
/**
* Get the list of EIPs from the configuration.
*
* @param myZone
* - the zone in which the instance resides.
* @return collection of EIPs to choose from for binding.
*/
private Collection getEIPsForZoneFromConfig(String myZone) {
List ec2Urls = DiscoveryManager.getInstance()
.getEurekaClientConfig().getEurekaServerServiceUrls(myZone);
return getEIPsFromServiceUrls(ec2Urls);
}
/**
* Get the list of EIPs from the ec2 urls.
*
* @param ec2Urls
* the ec2urls for which the EIP needs to be obtained.
* @return collection of EIPs.
*/
private Collection getEIPsFromServiceUrls(List ec2Urls) {
List returnedUrls = new ArrayList();
String region = DiscoveryManager.getInstance().getEurekaClientConfig().getRegion();
String regionPhrase="";
if (!US_EAST_1.equals(region)) {
regionPhrase = "." + region;
}
for (String cname : ec2Urls) {
int beginIndex = cname.indexOf("ec2-") + 4;
int endIndex = cname.indexOf(regionPhrase + ".compute");
String eipStr = cname.substring(beginIndex, endIndex);
String eip = eipStr.replaceAll("\\-", ".");
returnedUrls.add(eip);
}
return returnedUrls;
}
/**
* Get the list of EIPS from the DNS.
*
*
* This mechanism looks for the EIP pool in the zone the instance is in by
* looking up the DNS name {zone}.{region}.{domainName}. The
* zone is fetched from the {@link InstanceInfo} object;the region is picked
* up from the specified configuration
* {@link EurekaServerConfig#getRegion()};the domain name is picked up from
* the specified configuration {@link EurekaServerConfig#getDomainName()}.
*
*
* @param myZone
* the zone where this instance exist in.
* @return the collection of EIPs that exist in the zone this instance is
* in.
*/
private Collection getEIPsForZoneFromDNS(String myZone) {
List ec2Urls = DiscoveryManager.getInstance()
.getDiscoveryClient().getServiceUrlsFromDNS(myZone, true);
return getEIPsFromServiceUrls(ec2Urls);
}
/**
* Gets the EC2 service object to call AWS APIs.
*
* @return the EC2 service object to call AWS APIs.
*/
private AmazonEC2 getEC2Service() {
eurekaConfig = EurekaServerConfigurationManager.getInstance()
.getConfiguration();
String aWSAccessId = eurekaConfig.getAWSAccessId();
String aWSSecretKey = eurekaConfig.getAWSSecretKey();
AmazonEC2 ec2Service;
if (null != aWSAccessId && !"".equals(aWSAccessId) &&
null != aWSSecretKey && !"".equals(aWSSecretKey)) {
ec2Service = new AmazonEC2Client(new BasicAWSCredentials(
aWSAccessId, aWSSecretKey));
}
else
{
ec2Service = new AmazonEC2Client(
new InstanceProfileCredentialsProvider());
}
String region = DiscoveryManager.getInstance().getEurekaClientConfig()
.getRegion();
region = region.trim().toLowerCase();
ec2Service.setEndpoint("ec2." + region + ".amazonaws.com");
return ec2Service;
}
}
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