Dockerfile-alpine

FROM alpine

RUN apk add --no-cache git openssh-client curl unzip bash ttf-dejavu coreutils tini docker openjdk8

ARG user=jenkins
ARG group=jenkins
ARG uid=1000
ARG gid=1000
ARG http_port=8080
ARG agent_port=50000
ARG JENKINS_HOME=/var/jenkins_home
ARG REF=/usr/share/jenkins/ref

ENV JENKINS_HOME $JENKINS_HOME
ENV JENKINS_SLAVE_AGENT_PORT ${agent_port}
ENV REF $REF

# Jenkins is run with user `jenkins`, uid = 1000
# If you bind mount a volume from the host or a data container,
# ensure you use the same uid
RUN mkdir -p $JENKINS_HOME \
  && chown ${uid}:${gid} $JENKINS_HOME \
  && addgroup -g ${gid} ${group} \
  && adduser -h "$JENKINS_HOME" -u ${uid} -G ${group} -s /bin/bash -D ${user}

# Jenkins home directory is a volume, so configuration and build history
# can be persisted and survive image upgrades
VOLUME $JENKINS_HOME

# $REF (defaults to `/usr/share/jenkins/ref/`) contains all reference configuration we want
# to set on a fresh new installation. Use it to bundle additional plugins
# or config file with your custom jenkins Docker image.
RUN mkdir -p ${REF}/init.groovy.d

# jenkins version being bundled in this docker image
ARG JENKINS_VERSION
ENV JENKINS_VERSION ${JENKINS_VERSION:-2.213}

# jenkins.war checksum, download will be validated using it
ARG JENKINS_SHA=fdb8c094bd881403bd33c88c5e9bb634977689016c61c92d56087a89f7f5f554

# Can be used to customize where jenkins.war get downloaded from
ARG JENKINS_URL=https://repo.jenkins-ci.org/public/org/jenkins-ci/main/jenkins-war/${JENKINS_VERSION}/jenkins-war-${JENKINS_VERSION}.war

# could use ADD but this one does not check Last-Modified header neither does it allow to control checksum
# see https://github.com/docker/docker/issues/8331
RUN curl -fsSL ${JENKINS_URL} -o /usr/share/jenkins/jenkins.war \
  && echo "${JENKINS_SHA}  /usr/share/jenkins/jenkins.war" | sha256sum -c -

ENV JENKINS_UC https://updates.jenkins.io
ENV JENKINS_UC_EXPERIMENTAL=https://updates.jenkins.io/experimental
ENV JENKINS_INCREMENTALS_REPO_MIRROR=https://repo.jenkins-ci.org/incrementals
RUN chown -R ${user} "$JENKINS_HOME" "$REF"

# for main web interface:
EXPOSE ${http_port}

# will be used by attached slave agents:
EXPOSE ${agent_port}

ENV COPY_REFERENCE_FILE_LOG $JENKINS_HOME/copy_reference_file.log

HEALTHCHECK CMD curl --fail http://127.0.0.1:8080/login?from=|| exit 1

USER ${user}

COPY jenkins-support /usr/local/bin/jenkins-support
COPY jenkins.sh /usr/local/bin/jenkins.sh
COPY tini-shim.sh /bin/tini
ENTRYPOINT ["/sbin/tini", "--", "/usr/local/bin/jenkins.sh"]

# from a derived Dockerfile, can use `RUN plugins.sh active.txt` to setup $REF/plugins from a support bundle
COPY plugins.sh /usr/local/bin/plugins.sh
COPY install-plugins.sh /usr/local/bin/install-plugins.sh