jenkins/agent Docker Image

Jenkins Agent Docker image

This is a base image for Docker, which includes Java and the Jenkins agent executable (agent.jar). This executable is an instance of the https://github.com/jenkinsci/remoting. Java version depends on the image and the platform, see the Configurations section below.

Usage

This image is used as the basis for the https://github.com/jenkinsci/docker-agents/tree/master/README_inbound-agent.md image. In that image, the container is launched externally and attaches to Jenkins.

This image may instead be used to launch an agent using the Launch method of Launch agent via execution of command on the controller. For example on Linux you can try

sh
docker run -i --rm --name agent --init jenkins/agent java -jar /usr/share/jenkins/agent.jar

after setting Remote root directory to /home/jenkins/agent.

or if using Windows Containers

powershell
docker run -i --rm --name agent --init jenkins/agent:jdk25-windowsservercore-ltsc2022 java -jar C:/ProgramData/Jenkins/agent.jar

after setting Remote root directory to C:\Users\jenkins\Agent.

Agent Work Directories

Starting from https://github.com/jenkinsci/remoting/blob/master/CHANGELOG.md#38 there is a support of Work directories, which provides logging by default and change the JAR Caching behavior.

Call example for Linux:

sh
docker run -i --rm --name agent1 --init -v agent1-workdir:/home/jenkins/agent jenkins/agent java -jar /usr/share/jenkins/agent.jar -workDir /home/jenkins/agent

Call example for Windows Containers:

powershell
docker run -i --rm --name agent1 --init -v agent1-workdir:C:/Users/jenkins/Work jenkins/agent:jdk25-windowsservercore-ltsc2022 java -jar C:/ProgramData/Jenkins/agent.jar -workDir C:/Users/jenkins/Work

Configurations

The image has several supported configurations, which can be accessed via the lists of tags that can be consulted at https://github.com/jenkinsci/docker-agents/tree/master/tests/golden/

The file https://github.com/jenkinsci/docker-agents/blob/master/docker-bake.hcl defines all the configuration for Linux images and their associated tags.

There are also versioned tags in DockerHub, and they are recommended for production use. See the full list at https://hub.docker.com/r/jenkins/agent/tags

Timezones

By default, the image is using the Etc/UTC timezone. If you want to use the timezone of your machine, you can mount the /etc/localtime file from the host (as per https://github.com/moby/moby/issues/***#issuecomment-89697533) and the /etc/timezone from the host too.

bash
docker run --rm --tty --interactive --entrypoint=date --volume=/etc/localtime:/etc/localtime:ro --volume=/etc/timezone:/etc/timezone:ro jenkins/agent
Fri Nov 25 18:27:22 CET 2022

You can also set the TZ environment variable to the desired timezone. TZ is a standard POSIX environment variable used by many images, see *** for a list of valid values. The next command is run on a machine using the Europe/Paris timezone a few seconds after the previous one.

bash
docker run --rm --tty --interactive --env TZ=Asia/Shanghai --entrypoint=date jenkins/agent
Sat Nov 26 01:27:58 CST 2022

Using the jenkins/agent image as a base image

Should you want to adapt the jenkins/agent image to your local timezone while creating your own image based on it, you could use the following command (inspired by issue #https://github.com/jenkinsci/docker-inbound-agent/issues/291):

dockerfile
FROM jenkins/agent as agent
 [...]
ENV TZ=Asia/Shanghai
 [...]
RUN ln -snf /usr/share/zoneinfo/"${TZ}" /etc/localtime && echo "${TZ}" > /etc/timezone \
    && dpkg-reconfigure -f noninteractive tzdata \
 [...]

Changelog

See https://github.com/jenkinsci/docker-agents/releases for versions 3.35-1 and above. There is no changelog for previous versions, see the commit history.

Jenkins remoting changelogs are available at https://github.com/jenkinsci/remoting/releases.