Windows10环境下如何通过Dockerfile构建含预定义任务的Jenkins主节点镜像

Hey there! I totally get how frustrating it is to spend two days digging through docs and only get partial results when building a custom Jenkins master image. Let's walk through how to bake in all the pieces you need—plugins, users, pre-configured jobs, agent nodes, and general settings—so you can get a fully functional Jenkins instance right out of the box.

1. Start with a Solid Base Image #

First, use the official Jenkins LTS image as your foundation—it's well-maintained and avoids compatibility headaches. For Windows 10, make sure your Docker is using the WSL 2 backend (it's faster and handles Linux containers better than the old Hyper-V setup).

In your Dockerfile, start with:

FROM jenkins/jenkins:lts
USER root

We switch to root first to handle setup tasks that need elevated permissions, then switch back later.

2. Pre-Install Required Plugins #

Jenkins has a built-in script install-plugins.sh that makes installing plugins a breeze. Create a plugins.txt file in your build directory with all the plugins you need (include versions if you want consistency):

git:latest
maven-plugin:latest
docker-plugin:latest
credentials-binding:latest
ssh-slaves:latest
# Add any other plugins you use regularly

Then add this to your Dockerfile:

COPY plugins.txt /usr/share/jenkins/ref/plugins.txt
RUN jenkins-plugin-cli -f /usr/share/jenkins/ref/plugins.txt

3. Create a Pre-Defined Admin User #

Hardcoding users directly in config.xml can break across Jenkins versions, so use a Groovy init script instead—it's the supported way to bootstrap users. Create a file init.groovy.d/create-admin-user.groovy:

import jenkins.model.Jenkins
import hudson.security.User
import hudson.security.HudsonPrivateSecurityRealm

def jenkins = Jenkins.getInstance()
def realm = new HudsonPrivateSecurityRealm(false)
def username = "admin"
def password = "your-secure-password"

// Create user if they don't exist
if (!User.exists(username)) {
    realm.createAccount(username, password)
    jenkins.setSecurityRealm(realm)
    jenkins.save()
}

Copy this into your image with:

COPY init.groovy.d/ /usr/share/jenkins/ref/init.groovy.d/

4. Apply General Jenkins Configuration #

For global settings like tool paths (JDK, Maven), proxy settings, or build retention policies, you can either:

• Export the config.xml from a working Jenkins instance and copy it into /usr/share/jenkins/ref/
• Use another Groovy script to set these values programmatically (more maintainable long-term)

Example Groovy script for setting JDK and Maven paths (init.groovy.d/tool-config.groovy):

import jenkins.model.Jenkins
import hudson.tools.JDKInstallation
import hudson.tools.MavenInstallation

def jenkins = Jenkins.getInstance()

// Configure JDK
def jdkInstall = new JDKInstallation("OpenJDK11", "/usr/local/openjdk-11", [])
jenkins.getDescriptorByType(hudson.tools.JDKInstallation.DescriptorImpl.class).setInstallations(jdkInstall)

// Configure Maven
def mavenInstall = new MavenInstallation("Maven3", "/usr/share/maven", [])
jenkins.getDescriptorByType(hudson.tools.MavenInstallation.DescriptorImpl.class).setInstallations(mavenInstall)

jenkins.save()

5. Add Pre-Defined Jobs #

If you have existing jobs you want to include, simply copy their job directories into the image. First, export the job from your current Jenkins instance (zip up the jobs/YourJobName folder), then unzip it in your build directory. Add this to your Dockerfile:

COPY jobs/ /var/jenkins_home/jobs/
RUN chown -R jenkins:jenkins /var/jenkins_home/jobs

The chown step is crucial—Jenkins runs as the jenkins user, so it needs ownership of these files to modify them later.

6. Configure Agent Nodes #

To pre-configure agent nodes (either static SSH agents or Docker cloud agents), use another Groovy script. Example for a static SSH agent (init.groovy.d/configure-agent.groovy):

import jenkins.model.Jenkins
import hudson.slaves.DumbSlave
import hudson.slaves.SSHLauncher
import hudson.plugins.sshslaves.verifiers.NonVerifyingKeyVerificationStrategy

def jenkins = Jenkins.getInstance()

// Create a static SSH agent
def agentName = "my-static-agent"
def agentDescription = "Pre-configured static SSH agent"
def agentRemoteFS = "/home/jenkins"
def agentLabels = "build-node"
def agentLauncher = new SSHLauncher("agent-hostname", 22, "jenkins-agent-key", "", "", "", "", new NonVerifyingKeyVerificationStrategy())

def agent = new DumbSlave(agentName, agentDescription, agentRemoteFS, "1", Node.Mode.NORMAL, agentLabels, agentLauncher, new hudson.slaves.RetentionStrategy.Always(), [])

// Add agent if it doesn't exist
if (!jenkins.getNode(agentName)) {
    jenkins.addNode(agent)
    jenkins.save()
}

Adjust the hostname, credentials, and settings to match your agent setup.

7. Final Dockerfile Cleanup #

Switch back to the jenkins user before finishing, and set the working directory:

USER jenkins
WORKDIR /var/jenkins_home

8. Build and Test Your Image #

On Windows 10, open PowerShell or WSL 2 terminal, navigate to your build directory, and run:

docker build -t my-custom-jenkins .
docker run -p 8080:8080 -p 50000:50000 my-custom-jenkins

Wait a minute for Jenkins to start, then visit http://localhost:8080—you should be able to log in with your pre-defined admin user, see all your plugins, pre-configured jobs, and agent nodes ready to go.

Quick Windows 10 Tips #

• If you run into file permission issues when copying files, make sure your build directory is in the WSL 2 filesystem (e.g., /home/your-user/jenkins-build) instead of a Windows folder—this avoids cross-filesystem permission quirks.
• Double-check that Docker Desktop is set to use WSL 2 (Settings > Resources > WSL Integration).

内容的提问来源于stack exchange，提问作者aoki