SshWaiter.java

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.ow2.choreos.utils;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

import org.apache.log4j.Logger;

/**
 * Returns a SSH connection to a give node.
 * 
 * If connection is not successfully established within the given timeout, an
 * exception is thrown.
 * 
 * @author leonardo
 * 
 */
public class SshWaiter {

    private Logger logger = Logger.getLogger(SshWaiter.class);

    public SshUtil waitSsh(String ip, String user, String keyPath, int timeoutSeconds) throws SshNotConnected {

        SshWaiterCallable callable = new SshWaiterCallable(ip, user, keyPath);
        ExecutorService executor = Executors.newSingleThreadExecutor();
        Future<SshUtil> future = executor.submit(callable);

        Concurrency.waitExecutor(executor, timeoutSeconds, TimeUnit.SECONDS, logger, "Could not ssh into node " + ip);

        try {
            SshUtil ssh = Concurrency.checkAndGetFromFuture(future);
            if (ssh != null) {
                return ssh;
            } else {
                throw new SshNotConnected("Could not SSH into " + ip);
            }
        } catch (ExecutionException e) {
            throw new SshNotConnected("Could not SSH into " + ip);
        } catch (IllegalStateException e) {
            throw new SshNotConnected("Could not SSH into " + ip);
        }
    }

    private class SshWaiterCallable implements Callable<SshUtil> {

        private String ip, user, keyPath;

        public SshWaiterCallable(String ip, String user, String keyPath) {
            this.ip = ip;
            this.user = user;
            this.keyPath = keyPath;
        }

        @Override
        public SshUtil call() throws Exception {
            SshUtil ssh = new SshUtil(ip, user, keyPath);
            while (!ssh.isAccessible()) {
                logger.debug("Trying SSH into " + ip + " again in 5 seconds");
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    String msg = "VM " + ip + " not accessible!";
                    logger.warn(msg);
                    throw new IllegalStateException(msg);
                }
            }
            ssh.disconnect();
            return ssh;
        }
    }

}