korekontrol/docker-jnlp-slave-docker repository overview

⁠Jenkins JNLP Agent Docker image with docker inside

This is an image for Jenkins⁠ agent (FKA "slave"/"worker") using JNLP to establish connection. This agent is powered by the Jenkins Remoting library⁠, which version is being taken from the base Docker Agent⁠ image.

It includes addionally to original image tools useful on CI/CD workers:

• docker installed locally for docker-inside-docker or docker-outside-docker scenario
• awscli
• docker-compose
• j2cli
• kubectl
• helm

See Jenkins Distributed builds⁠ for more info.

⁠Running

To run a Docker container

docker run korekontrol/jnlp-slave-docker -url http://jenkins-server:port <secret> <agent name>

Optional environment variables:

• JENKINS_URL: url for the Jenkins server, can be used as a replacement to -url option, or to set alternate jenkins URL
• JENKINS_TUNNEL: (HOST:PORT) connect to this agent host and port instead of Jenkins server, assuming this one do route TCP traffic to Jenkins master. Useful when when Jenkins runs behind a load balancer, reverse proxy, etc.
• JENKINS_SECRET: agent secret, if not set as an argument
• JENKINS_AGENT_NAME: agent name, if not set as an argument

⁠Running docker inside docker

If you want to use Jenkins in a container for building and running docker images, you must run docker inside/outside docker. Two scenarios are possible - see: https://applatix.com/case-docker-docker-kubernetes-part/⁠ Docker outside docker seems very slow...

⁠Configuration specifics

⁠Enabled JNLP protocols

By default, the JNLP3-connect⁠ is disabled due to the known stability and scalability issues. You can enable this protocol on your own risk using the JNLP_PROTOCOL_OPTS=-Dorg.jenkinsci.remoting.engine.JnlpProtocol3.disabled=false property (the protocol should be enabled on the master side as well).

In Jenkins versions starting from 2.27 there is a JNLP4-connect⁠ protocol. If you use Jenkins 2.32.x LTS, it is recommended to enable the protocol on your instance.

⁠Amazon ECS

Make sure your ECS container agent is updated⁠ before running. Older versions do not properly handle the entryPoint parameter. See the entryPoint⁠ definition for more information.

⁠Credits

Created by Marek Obuchowicz⁠ from KoreKontrol - kubernetes consulting⁠

⁠License

MIT⁠