Docker for Springboot

Docker is a container management service. The keywords of Docker are develop, ship and run anywhere. The whole idea of Docker is for developers to easily develop applications, ship them into containers which can then be deployed anywhere.

To dockerize an App , we'd need to create a Dockerfile.

Follow below steps to create a Dockerfile for Dockerizing a Springboot App -

Create a file named - Dockerfile and copy below content

note : f is always small in Dockerfile

FROM openjdk:8-jdk-alpine

RUN mkdir -p /tmp

WORKDIR /tmp

ADD /target/sample-app.jar sample-app.jar

ENTRYPOINT ["java",  "-jar" , "/tmp/sample-app.jar" ]

If you have jar pushed to a remote artifactory you can download it using wget.
Use below Dockerfile for remote repo

FROM openjdk:8-jdk-alpine

RUN mkdir -p /tmp

WORKDIR /tmp
wget <url of repo>/sample-app.jar

ENTRYPOINT ["java",  "-jar" , "/tmp/sample-app.jar" ]

Build the docker image

docker build -t sample-docker-build:0.1  .

To Run the Docker image 

docker run  -p 9001:8080sample-docker-build:0.1

•  8080 is the default port on which springboot app runs
•  9001 is the port exposed for it, so if a user has to access the app it would be 9001.
•  You can expose the same port at which the app is running