Elements of Dockerfile (OpenShift Containers & Kubernetes Part-12) RedHat EX180 EX288
Correct way of writing Dockerfile (OpenShift Containers & Kubernetes Part-12)
FROM, ADD, RUN, WORKDIR, ENV, EXPOSE, USER, CMD, ENTRYPOINT
CMD vs ENTRYPOINT
ADD vs COPY
Architecture of Dockerfile
Dockerfile layers
---- Dockerfile used to explain concept ----
dockerfile to build image for JBoss EAP 6.4
start from rhel 7.7
FROM ubi7/ubi:7.7
file author / maintainer
MAINTAINER "Tejendra Rana" "[email protected]"
update OS
RUN yum -y update && \
yum -y install sudo openssh-clients telnet unzip java-1.8.0-openjdk-devel && \
yum clean all
enabling sudo group
enabling sudo over ssh
RUN echo '%wheel ALL=(ALL) NOPASSWD: ALL' >> /etc/sudoers && \
sed -i 's/.*requiretty$/Defaults !requiretty/' /etc/sudoers
add a user for the application, with sudo permissions
RUN useradd -m jboss ; echo jboss: | chpasswd ; usermod -a -G wheel jboss
create workdir
RUN mkdir -p /opt/rh
WORKDIR /opt/rh
install JBoss EAP 6.4.0
ADD jboss-eap-6.4.0.zip /tmp/jboss-eap-6.4.0.zip
RUN unzip /tmp/jboss-eap-6.4.0.zip
set environment
ENV JBOSS_HOME /opt/rh/jboss-eap-6.4
create JBoss console user
RUN $JBOSS_HOME/bin/add-user.sh admin admin@2016 --silent
configure JBoss
RUN echo "JAVA_OPTS=\"\$JAVA_OPTS -Djboss.bind.address=0.0.0.0 -Djboss.bind.address.management=0.0.0.0\"" >> $JBOSS_HOME/bin/standalone.conf
set permission folder
RUN chown -R jboss:jboss /opt/rh
JBoss ports
EXPOSE 8080 9990 9999
start JBoss
ENTRYPOINT $JBOSS_HOME/bin/standalone.sh -c standalone-full-ha.xml
deploy app
ADD myapp.war "$JBOSS_HOME/standalone/deployments/"
USER jboss
CMD /bin/bash