In my
previous post, I explained how to create a simple image, that echoes message to
the console. In this post, I am going to explain how to build a docker image
that runs java application in it.
Step 1: Create a directory ‘helloWorldJava’
Step 2: Create ‘Dockerfile’.
$mkdir helloWorldJava $ $cd helloWorldJava/ $touch Dockerfile $ $ls Dockerfile $
Step 3: Update Dockerfile with below content.
Dockerfile
FROM openjdk CMD java -version
Step 4: Build the docker image by executing
below command from the directory where the 'Dockerfile' is located.
docker
image build -t hellojava .
$ls Dockerfile $ $docker image build -t hellojava . Sending build context to Docker daemon 2.048kB Step 1/2 : FROM openjdk latest: Pulling from library/openjdk 35defbf6c365: Pull complete 5362bf1d5ff8: Pull complete 074486834918: Pull complete Digest: sha256:f0de92462537be994d15bbd6423e432caa699c61c131d3351ee10eb279dcb5f4 Status: Downloaded newer image for openjdk:latest ---> 831a029b6add Step 2/2 : CMD java -version ---> Running in 8c3d41c012f4 Removing intermediate container 8c3d41c012f4 ---> c8cb97224038 Successfully built c8cb97224038 Successfully tagged hellojava:latest
Step 5: Execute the command ‘docker image ls’
to see all the available images. You can see two images ‘openjdk’ and
‘hellojava’.
$docker image ls REPOSITORY TAG IMAGE ID CREATED SIZE hellojava latest c8cb97224038 52 seconds ago 470MB openjdk latest 831a029b6add 6 days ago 470MB
Step 6: Run the container with image hellojava
by executing the command ‘docker run hellojava’.
$docker run hellojava openjdk version "12.0.1" 2019-04-16 OpenJDK Runtime Environment (build 12.0.1+12) OpenJDK 64-Bit Server VM (build 12.0.1+12, mixed mode, sharing)
That’s it
you are done with your first Java application.
Since I do
not specify any tag for openjdk, it will use latest jdk image. If you want to
use a specific version of the image, append the : followed by tag name.
Example
FROM
openjdk:7u201-alpine
FROM
openjdk:8u201-alpine
FROM
openjdk:13-jdk-windowsservercore
You can
see all the available tags for openjdk from below location.
