/*
* 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.catalina.tribes.membership.cloud;
import java.io.IOException;
import java.io.Serializable;
import java.net.InetAddress;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.time.Instant;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import org.apache.catalina.tribes.ChannelListener;
import org.apache.catalina.tribes.Heartbeat;
import org.apache.catalina.tribes.Member;
import org.apache.catalina.tribes.membership.Membership;
import org.apache.catalina.tribes.membership.MembershipProviderBase;
import org.apache.catalina.tribes.util.StringManager;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
public abstract class CloudMembershipProvider extends MembershipProviderBase implements Heartbeat, ChannelListener {
private static final Log log = LogFactory.getLog(CloudMembershipProvider.class);
protected static final StringManager sm = StringManager.getManager(CloudMembershipProvider.class);
protected static final String CUSTOM_ENV_PREFIX = "OPENSHIFT_KUBE_PING_";
protected String url;
protected StreamProvider streamProvider;
protected int connectionTimeout;
protected int readTimeout;
protected Instant startTime;
protected MessageDigest md5;
protected Map<String,String> headers = new HashMap<>();
protected String localIp;
protected int port;
protected long expirationTime = 5000;
public CloudMembershipProvider() {
try {
md5 = MessageDigest.getInstance("md5");
} catch (NoSuchAlgorithmException e) {
// Ignore
}
}
/**
* Get value of environment variable.
*
* @param keys the environment variables
*
* @return the env variables values, or null if not found
*/
protected static String getEnv(String... keys) {
String val = null;
for (String key : keys) {
val = System.getenv(key);
if (val != null) {
break;
}
}
return val;
}
/**
* Get the Kubernetes namespace, or "tomcat" if the Kubernetes environment variable cannot be found (with a warning
* log about the missing namespace).
*
* @return the namespace
*/
protected String getNamespace() {
String namespace = getEnv(CUSTOM_ENV_PREFIX + "NAMESPACE", "KUBERNETES_NAMESPACE");
if (namespace == null || namespace.isEmpty()) {
log.warn(sm.getString("kubernetesMembershipProvider.noNamespace"));
namespace = "tomcat";
}
return namespace;
}
@Override
public void init(Properties properties) throws IOException {
startTime = Instant.now();
CloudMembershipService service = (CloudMembershipService) this.service;
connectionTimeout = service.getConnectTimeout();
readTimeout = service.getReadTimeout();
expirationTime = service.getExpirationTime();
localIp = InetAddress.getLocalHost().getHostAddress();
port = Integer.parseInt(properties.getProperty("tcpListenPort"));
}
@Override
public void start(int level) throws Exception {
if (membership == null) {
membership = new Membership(service.getLocalMember(true));
}
service.getChannel().addChannelListener(this);
}
@Override
public boolean stop(int level) throws Exception {
return true;
}
@Override
public void heartbeat() {
Member[] announcedMembers = fetchMembers();
// Add new members or refresh the members in the membership
for (Member member : announcedMembers) {
updateMember(member, true);
}
// Remove non refreshed members from the membership
Member[] expired = membership.expire(expirationTime);
for (Member member : expired) {
updateMember(member, false);
}
}
/**
* Fetch current cluster members from the cloud orchestration.
*
* @return the member array
*/
protected abstract Member[] fetchMembers();
/**
* Add or remove specified member.
*
* @param member the member to add
* @param add true if the member is added, false otherwise
*/
protected void updateMember(Member member, boolean add) {
if (add && !membership.memberAlive(member)) {
return;
}
if (log.isDebugEnabled()) {
String message = add ? sm.getString("cloudMembershipProvider.add", member) :
sm.getString("cloudMembershipProvider.remove", member);
log.debug(message);
}
Runnable r = () -> {
Thread currentThread = Thread.currentThread();
String name = currentThread.getName();
try {
String threadName = add ? "CloudMembership-memberAdded" : "CloudMembership-memberDisappeared";
currentThread.setName(threadName);
if (add) {
membershipListener.memberAdded(member);
} else {
membershipListener.memberDisappeared(member);
}
} finally {
currentThread.setName(name);
}
};
executor.execute(r);
}
@Override
public void messageReceived(Serializable msg, Member sender) {
}
@Override
public boolean accept(Serializable msg, Member sender) {
return false;
}
}