DockerOnceRetentionStrategy.java

package com.nirima.jenkins.plugins.docker.strategy;

import hudson.Extension;
import hudson.model.*;
import hudson.slaves.*;
import hudson.util.TimeUnit2;
import jenkins.model.Jenkins;
import org.jenkinsci.plugins.durabletask.executors.ContinuableExecutable;
import org.kohsuke.accmod.Restricted;
import org.kohsuke.accmod.restrictions.NoExternalUse;
import org.kohsuke.stapler.DataBoundConstructor;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Mix of {@link org.jenkinsci.plugins.durabletask.executors.OnceRetentionStrategy} (1.3) and {@link CloudRetentionStrategy}
 * that allows configure it parameters and has Descriptor.
 * <p/>
 * Retention strategy that allows a cloud slave to run only a single build before disconnecting.
 * A {@link ContinuableExecutable} does not trigger termination.
 */
public class DockerOnceRetentionStrategy extends CloudRetentionStrategy implements ExecutorListener {

    private static final Logger LOGGER = Logger.getLogger(DockerOnceRetentionStrategy.class.getName());

    private int idleMinutes = 10;
    private transient boolean terminating;

    /**
     * Creates the retention strategy.
     *
     * @param idleMinutes number of minutes of idleness after which to kill the slave; serves a backup in case the strategy fails to detect the end of a task
     */
    @DataBoundConstructor
    public DockerOnceRetentionStrategy(int idleMinutes) {
        super(idleMinutes);
        this.idleMinutes = idleMinutes;
    }

    public int getIdleMinutes() {
        return idleMinutes;
    }

    @Override
    public long check(final AbstractCloudComputer c) {
        // When the slave is idle we should disable accepting tasks and check to see if it is already trying to
        // terminate. If it's not already trying to terminate then lets terminate manually.
        if (c.isIdle() && !disabled) {
            final long idleMilliseconds = System.currentTimeMillis() - c.getIdleStartMilliseconds();
            if (idleMilliseconds > TimeUnit2.MINUTES.toMillis(idleMinutes)) {
                LOGGER.log(Level.FINE, "Disconnecting {0}", c.getName());
                done(c);
            }
        }

        // Return one because we want to check every minute if idle.
        return 1;
    }

    @Override
    public void start(AbstractCloudComputer c) {
        if (c.getNode() instanceof EphemeralNode) {
            throw new IllegalStateException("May not use OnceRetentionStrategy on an EphemeralNode: " + c);
        }
        super.start(c);
    }

    @Override
    public void taskAccepted(Executor executor, Queue.Task task) {
    }

    @Override
    public void taskCompleted(Executor executor, Queue.Task task, long durationMS) {
        done(executor);
    }

    @Override
    public void taskCompletedWithProblems(Executor executor, Queue.Task task, long durationMS, Throwable problems) {
        done(executor);
    }

    private void done(Executor executor) {
        final AbstractCloudComputer<?> c = (AbstractCloudComputer) executor.getOwner();
        Queue.Executable exec = executor.getCurrentExecutable();
        if (exec instanceof ContinuableExecutable && ((ContinuableExecutable) exec).willContinue()) {
            LOGGER.log(Level.FINE, "not terminating {0} because {1} says it will be continued", new Object[]{c.getName(), exec});
            return;
        }
        LOGGER.log(Level.FINE, "terminating {0} since {1} seems to be finished", new Object[]{c.getName(), exec});
        done(c);
    }

    private void done(final AbstractCloudComputer<?> c) {
        c.setAcceptingTasks(false); // just in case
        synchronized (this) {
            if (terminating) {
                return;
            }
            terminating = true;
        }
        Computer.threadPoolForRemoting.submit(new Runnable() {
            @Override
            public void run() {
                Queue.withLock( new Runnable() {
                    @Override
                    public void run() {
                        try {
                            AbstractCloudSlave node = c.getNode();
                            if (node != null) {
                                node.terminate();
                            }
                        } catch (InterruptedException | IOException e) {
                            LOGGER.log(Level.WARNING, "Failed to terminate " + c.getName(), e);
                            synchronized (DockerOnceRetentionStrategy.this) {
                                terminating = false;
                            }
                        }
                    }
                });
            }
        });
    }

    @Override
    public DescriptorImpl getDescriptor() {
        return DESCRIPTOR;
    }

    @Restricted(NoExternalUse.class)
    public static final DescriptorImpl DESCRIPTOR = new DescriptorImpl();

    @Extension
    public static final class DescriptorImpl extends Descriptor<RetentionStrategy<?>> {
        @Override
        public String getDisplayName() {
            return "Docker Once Retention Strategy";
        }
    }

}