Overview

Lets you configure tools so that slaves will install them on demand whenever running a job that needs them. This could be especially useful when running a large farm of slaves in a cloud which all start with a minimal operating system configuration.

Several techniques are already supported: run arbitrary shell command; download & unpack archive from arbitrary URL; download and install official Sun JDK, Ant release, or Maven release.

The configuration is part of a tool; a project owner just picks a tool (JDK, Ant, Maven, ...) by name as usual, and may observe a build running some extra steps if it needs to perform an installation, but it is otherwise transparent. Installers can be limited to slaves marked with a label.

Demo Configuration

Master

Hudson 1.311 on localhost:8080 with no executors.

Node config

One JNLP slave node ubuntu-vbox with one executor and Remote FS root set to /hudson.

Tool Config

1. JDK installations has one entry with name JDK 6 and a JDK installer set to 6u13.
2. Ant installation has one entry with name Ant 1.7.1 and an Ant installer set to 1.7.1.

Test Project

Freestyle project, no SCM. Two build steps:

1. Execute shell with Command:

   echo "JDK: $JAVA_HOME"
   echo '<project/>' > build.xml
   

2. Invoke Ant with Targets set to -version.

Slave

An Ubuntu 8.10 server installation inside VirtualBox (NAT networking) with only default-jre-headless installed and user hudson added.

/etc/rc.local

#!/bin/sh -e
su - hudson -c /hudson/slave-jnlp 2>&1 | perl -p -e 's/\n/\r\n/g' 1>&2 &

/etc/sudoers

# ...
hudson ALL=NOPASSWD: ALL

/hudson/slave-jnlp

#!/bin/sh
dir=`dirname $0`
server=http://10.0.2.2:8080
node=ubuntu-vbox
while :
do
    wget -O $dir/slave.jar $server/jnlpJars/slave.jar && \
        java -jar $dir/slave.jar -jnlpUrl $server/computer/$node/slave-agent.jnlp
    sleep 15
done

Expected project console output

...
Building remotely on ubuntu-vbox
...
JDK: /hudson/tools/JDK_6
...
[...] $ /hudson/tools/Ant_1.7.1/bin/ant -version
Apache Ant version 1.7.1 compiled on June 27 2008
Finished: SUCCESS

To be done

1. Problems installing JDK on Windows with spaces in path.

Suggested features

1. Install tools from an SCM such as Subversion.
2. Upload a tool archive directly into Hudson's web GUI.
3. Cache downloaded tools on master to avoid excess network traffic.
4. More flexible use of tools: issue #4532

More tools needed!

More things should extend ToolInstallation for this system to be really useful. An incomplete list:

1. Languages & frameworks
   1. Ruby
   2. Groovy
   3. Rails
2. Builders
   1. Rake
   2. Gradle
   3. NAnt
   4. MSBuild: issue #4120
3. SCMs
4. Mercurial (available as of 1.18)
   1. CVS
   2. Git
   3. unnecessary for SVN, which Hudson runs from Java