hudson.FileSystemProvisioner Maven / Gradle / Ivy

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package hudson;

import hudson.matrix.MatrixBuild;
import hudson.model.AbstractBuild;
import hudson.model.AbstractProject;
import hudson.model.Computer;
import hudson.model.Describable;
import hudson.model.Job;
import hudson.model.TaskListener;
import hudson.model.listeners.RunListener;
import hudson.util.DescriptorList;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * Prepares and provisions workspaces for {@link AbstractProject}s.
 *
 * 
 *
 *
 * 

 * STILL A WORK IN PROGRESS. SUBJECT TO CHANGE!
 *
 * TODO: is this per {@link Computer}? Per {@link Job}?
 *   -> probably per slave.
 *
 * 
Design Problems
 * 
 * 
 * Garbage collection of snapshots. When do we discard snapshots?
 * In one use case, it would be convenient to keep the snapshot of the
 * last promoted/successful build. So we need to define a mechanism
 * to veto GC of snapshot? like an interface that Action can implement?
 *
 * Snapshot should be obtained per user's direction. That would be a good
 * moment for the user to specify the retention policy.
 *
 * 

 * Configuration mechanism. Should we auto-detect FileSystemProvisioner
 * per OS? (but for example, zfs support would require the root access.)
 * People probably needs to be able to disable this feature, which means
 * one more configuration option. It's especially tricky because
 * during the configuration we don't know the OS type.
 *
 * OTOH special slave type like the ones for network.com grid can
 * hide this.
 * 
 *
 *
 * Recap
 *
 * To recap,
 *
 * - when a slave connects, we auto-detect the file system provisioner.
 *   (for example, ZFS FSP would check the slave root user prop
 *   and/or attempt to "pfexec zfs create" and take over.)
 *     -> hmm, is it better to do this manually?
 *
 * - the user may configure jobs for snapshot collection, along with
 *   the retention policy.
 *
 * Can't the 2nd step happen automatically, when someone else depends on
 * the workspace snapshot of the upstream? Yes, by using {@link RunListener}.
 * So this becomes like a special SCM type.
 *
 * To support promoted builds, we need an abstraction for permalinks.
 * This is also needed for other UI.
 *
 * @author Kohsuke Kawaguchi
 * @since 1.235
 */
public abstract class FileSystemProvisioner implements ExtensionPoint, Describable {
    /**
     * Called very early in the build (before a build places any files
     * in the workspace, such as SCM checkout) to provision a workspace
     * for the build.
     *
     * 
     * This method can prepare the underlying file system in preparation
     * for the later {@link #snapshot(AbstractBuild, FilePath, TaskListener)}.
     *
     * TODO : the method needs to be able to see the snapshot would
     * be later needed. In fact, perhaps we should only call this method
     * when Hudson knows that a snapshot is later needed?
     *
     * @param ws
     *      New workspace should be prepared in this location. This is the same value as
     *      {@code build.getProject().getWorkspace()} but passed separately for convenience.
     */
    public abstract void prepareWorkspace(AbstractBuild build, FilePath ws, TaskListener listener) throws IOException, InterruptedException;

    /**
     * When a project is deleted, this method is called to undo the effect of
     * {@link #prepareWorkspace(AbstractBuild, FilePath, TaskListener)}.
     */
    public abstract void discardWorkspace(AbstractProject project, TaskListener listener) throws IOException, InterruptedException;

//    public abstract void moveWorkspace(AbstractProject project, File oldWorkspace, File newWorkspace) throws IOException;

    /**
     * Obtains the snapshot of the workspace of the given build.
     *
     * 

     * The state of the build when this method is invoked depends on
     * the project type. Most would call this at the end of the build,
     * but for example {@link MatrixBuild} would call this after
     * SCM check out so that the state of the fresh workspace
     * can be then propagated to elsewhere.
     *
     * 
     * If the implementation of this method needs to store data in a file system,
     * do so under {@link AbstractBuild#getRootDir()}, since the lifecycle of
     * the snapshot is tied to the life cycle of a build.
     *
     * @param ws
     *      New workspace should be prepared in this location. This is the same value as
     *      {@code build.getProject().getWorkspace()} but passed separately for convenience.
     */
    public abstract WorkspaceSnapshot snapshot(AbstractBuild build, FilePath ws, TaskListener listener) throws IOException, InterruptedException;

    public abstract FileSystemProvisionerDescriptor getDescriptor();

    /**
     * A list of available file system provider types.
     */
    public static final DescriptorList LIST = new DescriptorList();

    /**
     * Default implementation.
     */
    public static final FileSystemProvisioner DEFAULT = new Default();

    /**
     * Default implementation that doesn't rely on any file system specific capability,
     * and thus can be used anywhere that Hudson runs.
     */
    public static final class Default extends FileSystemProvisioner {
        private Default() {}

        public void prepareWorkspace(AbstractBuild build, FilePath ws, TaskListener listener) throws IOException, InterruptedException {
            ws.mkdirs();
        }

        public void discardWorkspace(AbstractProject project, TaskListener listener) throws IOException, InterruptedException {
            project.getWorkspace().deleteRecursive();
        }

        /**
         * Creates a tar ball.
         */
        public WorkspaceSnapshot snapshot(AbstractBuild build, FilePath ws, TaskListener listener) throws IOException, InterruptedException {
            File wss = new File(build.getRootDir(),"workspace.zip");
            OutputStream os = new BufferedOutputStream(new FileOutputStream(wss));
            try {
                ws.createZipArchive(os);
            } finally {
                os.close();
            }
            return new WorkspaceSnapshotImpl();
        }

        public FileSystemProvisionerDescriptor getDescriptor() {
            return null;
        }

        public static final class WorkspaceSnapshotImpl extends WorkspaceSnapshot {
            public void restoreTo(AbstractBuild owner, FilePath dst, TaskListener listener) throws IOException, InterruptedException {
                File wss = new File(owner.getRootDir(),"workspace.zip");
                new FilePath(wss).unzip(dst);
            }
        }
    }
}