This plugin adds a new command 'distfork' to Jenkins CLI, which can be used to execute arbitrary command on a slave of your choice. The distfork command is modeled after ssh, but it's Jenkins aware — for example, instead of hardcoding a machine name, you can specify a label to let Jenkins choose a slave. This opens up a Jenkins cluster for doing all kinds of things without requiring a job/build notion.

Use Case

• You have a test that involves multiple nodes. Your test script can use distfork to launch additional JVMs on the Jenkins cluster to carry that out. Such test script can be run from both within Jenkins or from developer's laptops.
• You have some computation that is expensive or require specific environment (say, building JDK or building a virtual machine image.) You can submit such computation to Jenkins from your shell.
• As a basis for distributed scripting.

Usage

The following example runs "uname -a" command on a slave with the 'linux' label (if the -l option is optional.)

$ java -jar jenkins-cli.jar -s http://server/jenkins/ dist-fork -l linux uname -a
[distfork5384565281499633486.tmp] $ uname -a
Linux bear 2.6.28-13-generic #44-Ubuntu SMP Tue Jun 2 07:55:09 UTC 2009 x86_64 GNU/Linux

The following example starts a Tomcat somewhere in a Jenkins cluster, with a port-forwarding from the port 9999 to the HTTP listener of Tomcat.

% java -jar jenkins-cli.jar -s http://localhost:8080/ dist-fork -z ~/apache-tomcat-5.5.27.tar.gz \\
    -L 9999:localhost:8080 apache-tomcat-5.5.27/bin/catalina.sh run
[distfork6313354709312415597.tmp] $ apache-tomcat-5.5.27/bin/catalina.sh run
Jul 15, 2009 12:25:31 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The Apache Tomcat Native library which allows optimal performance in production environments was not found on ...
Jul 15, 2009 12:25:31 PM org.apache.coyote.http11.Http11BaseProtocol init
...

Features

• distfork executions are scheduled in the queue and run by an executor, just like normal builds. Thus it makes Jenkins aware of what slaves are busy and what are not.
• Each command execution gets a one-time temporary directory for its working directory. Jenkins will clean this up after the command exits, as well as terminating any remaining background processes to maintain the cluster health.
• Port-forwarding both ways so that you can talk to the remote process without knowing their actual IP addresses.
• Ability to stage the files before the process execution, and ability to bring back files after it ends.

Available Command Line Arguments

 -F LOCAL=REMOTE   : Remote files to be copied back to local locations after
                     the execution of a task
 -L PORT:HOST:PORT : Local to remote port forwarding
 -R PORT:HOST:PORT : Remote to local port forwarding
 -Z FILE           : Bring back the newly added/updated files in the target
                     remote machine after the end of the command by creating a
                     zip/tgz bundle and place this in the local file system by
                     this name.
 -d N              : Estimated duration of this task in milliseconds, or -1 if
                     unknown
 -e NAME=VAL       : Environment variables to set to the launched process
 -f REMOTE=LOCAL   : Local files to be copied to remote locations before the
                     exeuction of a task
 -l VAL            : Label for controlling where to execute this command
 -n VAL            : Human readable name that describe this command. Used in
                     Jenkins' UI.
 -z FILE           : Zip/tgz file to be extracted into the target remote
                     machine before execution of the command

Notes

• The -z -Z -f -F -L and -R options (file and port forwarding) will not work in a Jenkins with remoting based cli disabled (blog post on new CLI), except in 1.7+ with some modes of -z and -Z.

Changelog

Version 1.7 (Jan 29 2018)

• JENKINS-49205 - Permit file transfers under non-Remoting-based CLI Resolved

Version 1.6.0 (Mar 20 2017)

• fix SECURITY-386 / CVE-2017-2652

Version 1.5.0 (Mar 16 2017)

Now requires Jenkins 1.625.3 or higher.

• Merge PR#6 - if the copy operation fails do not leave a zero length file

Version 1.4.1 (Feb 10 2016)

• fix JENKINS-23567 prevent log spam
• fix JENKINS-16200 use the provided value for duration
• fix JENKINS-32648 log the name of the node used to run the command

Version 1.3 (Feb 25 2011)

• Update for Jenkins

Version 1.1 (Nov 19 2010)

• Update code for more recent Hudson
• Cut off the random meaningless name from the archive

Version 1.0 (Jul 15 2009)

• Initial release