Jenkins in Docker Container

This is the source code to create a Jenkins Docker container.

Folder Structure
Docker compose
Dockerfile
Jenkins Configuration
Container operation

Folder Structure

In your parent folder create a sub folder name say jenkins. All the docker specific files, can be kept in this folder. Your git repositories you can create under the parent directory where Jenkinsfile is exists.

Docker compose

As shown in the above screenshot, you have to have docker-compose.yml file:

version: "3.7"

services:
  jenkins:
    image: ojitha/pipelines-jenkins:29.06.2021
    ports:
      - "8080:8080"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    build:
      context: ./29.06.2021

you can find Jenkins specific configuration in the 29.06.2021 which was created based in the date.

Dockerfile

The Dockerfile is as follows:

FROM alpine:3.11 AS installer

ARG JENKINS_VERSION="2.289.1"

RUN apk add --no-cache curl
RUN apk add --no-cache --repository http://dl-cdn.alpinelinux.org/alpine/edge/community docker-cli
RUN curl -SL -o jenkins.war http://mirrors.jenkins.io/war-stable/$JENKINS_VERSION/jenkins.war

# Jenkins
FROM alpine:3.11

# jenkins deps
RUN apk add --no-cache \
    bash \
    coreutils \
    git \
    openjdk11 \
    openssh-client \
    ttf-dejavu \
    unzip 

# compose deps
RUN apk add --no-cache \
    gcc \
    libc-dev \
    libffi-dev \
    make \
    openssl-dev \
    python-dev \
    py-pip

RUN pip install --upgrade pip 
RUN pip install docker-compose

ARG JENKINS_VERSION="2.289.1"
ENV JENKINS_VERSION=${JENKINS_VERSION} \
    JENKINS_HOME="/data"

VOLUME ${JENKINS_HOME}

EXPOSE 8080
ENTRYPOINT java -Duser.home=${JENKINS_HOME} -Djenkins.install.runSetupWizard=false -jar /jenkins/jenkins.war

COPY --from=installer /usr/bin/docker /usr/bin/docker
COPY --from=installer /jenkins.war /jenkins/jenkins.war

COPY ./jenkins.install.UpgradeWizard.state ${JENKINS_HOME}/
COPY ./scripts/ ${JENKINS_HOME}/init.groovy.d/

Jenkins Configuration

The jenkins.install.UpgradeWizard.state file contains:

2.0

Jenkins admin and plugin configurations are in the scripts folder. Here the admin.groovy:

#!groovy
import jenkins.install.*;
import jenkins.model.*
import jenkins.security.s2m.AdminWhitelistRule
import hudson.security.*
import hudson.util.*;

def instance = Jenkins.getInstance()

def username = "ojitha"
def password = "ojitha"

def hudsonRealm = new HudsonPrivateSecurityRealm(false)
hudsonRealm.createAccount(username, password)
instance.setSecurityRealm(hudsonRealm)

def strategy = new FullControlOnceLoggedInAuthorizationStrategy()
instance.setAuthorizationStrategy(strategy)
instance.setInstallState(InstallState.INITIAL_SETUP_COMPLETED)
instance.save()

Jenkins.instance.getInjector().getInstance(AdminWhitelistRule.class).setMasterKillSwitch(false)

Here the install-plugins.groovy:

#!groovy
import jenkins.model.Jenkins;

pm = Jenkins.instance.pluginManager
uc = Jenkins.instance.updateCenter

pm.doCheckUpdatesServer()

["git", "workflow-aggregator", "blueocean"].each {
    if (! pm.getPlugin(it)) {
    deployment = uc.getPlugin(it).deploy(true)
    deployment.get()
    }
}

Container operation

To create container, run the following command in the parent directory level:

docker-compose -f jenkins/docker-compose.yml up -d

you can access Jenkins via http://localhost:8080 using user/pass ojitha/ojitha.

If you want to remove the container:

docker-compose -f jenkins/docker-compose.yml down

This source was written following a course¹ (author’s blog is https://blog.sixeyed.com) and modified to work with latest version of Jenkins.

Using Declarative Jenkins Pipelines ↩