DockerFile to run a java program

Question

Hi I\'m new to Docker and trying out to write a new image from the scratch. I am writing this dockerFile to compile and run a simple java program available in the same directory

Answer 1

Here I am writing all commands and code that need to execute in order to run a hello world program on docker container without any build tool like gradle or maven.

devopsrider@del1-lhp-n02552:~ sudo su
root@del1-lhp-n02552:~# mkdir devopsrider
root@del1-lhp-n02552:~# cd devopsrider
root@del1-lhp-n02552:~/devopsrider# vi Test.java

public class Test{
        public static void main(String args[]){
                System.out.println("Hello World");

        }
}

root@del1-lhp-n02552:~# javac Test.java
root@del1-lhp-n02552:~/devopsrider# ls
Test.class  Test.java

root@del1-lhp-n02552:~/devopsrider# vi manifest.txt
Manifest-Version: 1.2
Main-Class: Test

root@del1-lhp-n02552:~/devopsrider# jar cvfm Test.jar manifest.txt Test.class
added manifest
adding: Test.class(in = 413) (out= 287)(deflated 30%)

root@del1-lhp-n02552:~/devopsrider# ls
manifest.txt  Test.class  Test.jar  Test.java

root@del1-lhp-n02552:~# vi Dockerfile
FROM openjdk:8
ADD Test.jar Test.jar
ENTRYPOINT ["java", "-jar", "Test.jar"]

root@del1-lhp-n02552:~/devopsrider# docker build -f Dockerfile -t hello-world-image .

Sending build context to Docker daemon  6.656kB
Step 1/3 : FROM openjdk:8
8: Pulling from library/openjdk
Digest: sha256:c168e211f317cc5db38b19fe62641316dbc1e60e5b53ad45ee440ba8152c20b9
Status: Downloaded newer image for openjdk:8
 ---> 57c2c2d2643d
Step 2/3 : ADD Test.jar Test.jar
 ---> b7d512e51b60
Step 3/3 : ENTRYPOINT ["java", "-jar", "Test.jar"]
 ---> Running in 07c871318e8a
Removing intermediate container 07c871318e8a
 ---> 24b1a0acd314
Successfully built 24b1a0acd314
Successfully tagged hello-world-image:latest

root@del1-lhp-n02552:~/devopsrider# docker run hello-world-image
Hello World

For complete tutorial to run java Hello World program on docker container visit http://www.devopsrider.com/2019/11/19/hello-world-java-program-on-docker-container/