DevOps Classroom Series – 09/Feb/2020

Dockerfile instructions (others)

  • ARG:

    • is a variable that can be set during image build.
    • Scope: This ARG value will be available till the image is built
    • Refer Here
  • ENV:

    • this will be environment variable available in RUN container
    • These values can be set or changed while the container is created.
    • Refer Here



  • .dockerignore

CI/CD Pipeline with Docker containers


  • Create a jenkins job
  • Get the latest code from git
  • Build the package using build tools like maven
  • Using the package build create the docker image
  • tag the docker image and send it to the registry
  • pull the docker image from registry and deploy using k8s/swarm etc


  • Collection of Docker Images
  • DockerHub:
    • Before uploading images (push) to docker hub, login into docker hub from command line

Sample Scenario: Push gameoflife to docker hub

  • Clone the code
git clone
  • Build the code
mvn package
  • Create a Docker file at the root folder of game-of-life
FROM tomcat:8
LABEL owner=none
ADD ./gameoflife-web/target/gameoflife.war /usr/local/tomcat/webapps/gameoflife.war
CMD ["", "run"]
  • build the docker image
docker image build -t gol:1.0 .
  • login to docker hub
docker log
username: shaikkhajaibrahim
  • Now to push docker image to docker hub pattern is <username>/<imagename>:<tag>
docker image tag gol:1.0 shaikkhajaibrahim/gol:1.0
docker push shaikkhajaibrahim/gol:1.0

multistage builds

  • Multistage can be used to build applications and create docker images.

  • Refer Here

  • Lets build the application game of life using maven and create a docker image from the single docker file

FROM maven:3-jdk-8 as builder
RUN git clone
RUN cd /game-of-life
WORKDIR /game-of-life
RUN mvn package

FROM tomcat:8
LABEL owner=none
COPY --from=builder /game-of-life/gameoflife-web/target/gameoflife.war /usr/local/tomcat/webapps/gameoflife.war
CMD ["", "run"]

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