Docker image for inbound Jenkins agents

Important

This repository is deprecated, its content is now included in https://github.com/jenkinsci/docker-agent/.

Since jenkinsci/docker-agent#570 both agent and inbound-agent images are built from https://github.com/jenkinsci/docker-agent/ repository, thanks to the use of multi-stage Dockerfiles and to the use of targets.

See jenkinsci/docker-agent#569 for more details.

Note that it doesn't change anything on the Docker hub side, these images still have their own Docker repositories jenkins/agent and jenkins/inbound-agent.

❗ Warning! This image used to be published as jenkinsci/jnlp-slave and jenkins/jnlp-slave. These images are deprecated, use jenkins/inbound-agent.

This is an image for Jenkins agents using TCP or WebSockets to establish inbound connection to the Jenkins master. This agent is powered by the Jenkins Remoting library, which version is being taken from the base Docker Agent image.

See Using Agents for more info.

Configuring agents with this container image

Setup the agent on Jenkins

1. Go to your Jenkins dashboard
2. Go to Manage Jenkins option in main menu
3. Go to Nodes item in System Configuration
4. Go to New Node option in side menu
5. Fill the Node(agent) name and select the type; (e.g. Name: agent1, Type: Permanent Agent)
6. Now fill the fields like remote root directory, labels, # of executors, etc.

• Launch method is Launch agent by connecting it to the controller

7. Press the Save button and the agent1 will be registered, but offline for the time being. Click on it.
8. You should now see the secret. Use the secret value to pass it to the argument of container, or set to JENKINS_SECRET as environment variable.

Running this container

To run a Docker container

Note
Remember to replace the <secret> and <agent name> for secret and agent name, which can be you can get(and set) from above section.
Your agent node should be possible to connect to Jenkins controller with agent port (not Jenkins server's port like 80, 443, 8080), which can be set in Manage Jenkins > Security > Agent. Default port is 50000.

Linux agent:

docker run --init jenkins/inbound-agent -url http://jenkins-server:port <secret> <agent name>

Note: --init is necessary for correct subprocesses handling (zombie reaping)

Windows agent:

docker run jenkins/inbound-agent:windowsservercore-ltsc2019 -Url http://jenkins-server:port -Secret <secret> -Name <agent name>

To run a Docker container with Work Directory

Linux agent:

docker run --init jenkins/inbound-agent -url http://jenkins-server:port -workDir=/home/jenkins/agent <secret> <agent name>

Windows agent:

docker run jenkins/inbound-agent:windowsservercore-ltsc2019 -Url http://jenkins-server:port -WorkDir=C:/Jenkins/agent -Secret <secret> -Name <agent name>

Optional environment variables:

• JENKINS_JAVA_BIN: Path to Java executable to use instead of the default in PATH or obtained from JAVA_HOME
• JENKINS_JAVA_OPTS : Java Options to use for the remoting process, otherwise obtained from JAVA_OPTS, Warning ❗ For more information on Windows usage, please see the Windows Jenkins Java Opts section below.
• 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 controller. Useful when when Jenkins runs behind a load balancer, reverse proxy, etc.
• JENKINS_SECRET: (use only if not set as an argument) the secret as shown on the controller after creating the agent
• JENKINS_AGENT_NAME: (use only if not set as an argument) the name of the agent, it should match the name you specified when creating the agent on the controller
• JENKINS_AGENT_WORKDIR: agent work directory, if not set by optional parameter -workDir
• JENKINS_WEB_SOCKET: true if the connection should be made via WebSocket rather than TCP
• JENKINS_DIRECT_CONNECTION: (HOST:PORT) Connect directly to this TCP agent port, skipping the HTTP(S) connection parameter download.
• JENKINS_INSTANCE_IDENTITY: The base64 encoded InstanceIdentity byte array of the Jenkins controller. When this is set, the agent skips connecting to an HTTP(S) port for connection info.
• JENKINS_PROTOCOLS: Specify the remoting protocols to attempt when JENKINS_INSTANCE_IDENTITY is provided.

Example

1. Enter the command above.
2. Check the Jenkins dashboard if the agent is connected well.

Windows Jenkins Java Opts

The processing of the JENKINS_JAVA_OPTS environment variable or -JenkinsJavaOpts command line parameter follow the command parsing semantics of Powershell. This means that if a parameter contains any characters that are part of an expression in Powershell, it will need to be surrounded by quotes. For example:

-XX:+PrintCommandLineFlags --show-version

This would need to be escaped with quotes like this:

"-XX:+PrintCommandLineFlags" --show-version

Or another example: -Dsome.property=some value --show-version

This would need to be escaped like this:

"-Dsome.property='some value'" --show-version

Configuration specifics

Enabled JNLP protocols

As of version 3.40-1 this image only supports the JNLP4-connect protocol. Earlier, long-unsupported protocols have been removed. As a result, Jenkins versions prior to 2.32 are no longer supported.

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.