thedevopsstore / bootdocker

springboot application

bootdocker

Dockerize a Spring Boot Application

steps involved

• Create a Spring Boot Application
• Create Dockerfile
• Build executable jar file
• Build Docker image
• Run Docker container using the image built

Dockerfile

FROM adoptopenjdk/openjdk15:ubi  # FROM:To build a Docker image using a Dockerfile,we need a base layer
ENV APP_HOME=/usr/app/  # This sets the environmental variable. APP_HOME=/usr/app/ simply assigns the directory /usr/app/ to APP_HOME
WORKDIR $APP_HOME  # This is setting up the working directory or the current directory
COPY build/libs/*.jar app.jar # copies the build the jar file using gradle into the work directory
EXPOSE 8080 # Expose sets the port number to connect to the host
CMD ["java", "-jar", "app.jar"] # this is the command that runs when the container starts or runs

Build executable jar file

Ignore local setup if you want to build using github actions

prerequsites

• Install jdk 15 locally
• Install gradle
• Build the code using ./gradlew build

Build Docker Image and run the container

docker image build -t lwplapbs/bootdocker:1 .

docker run -d --name bootdocker -p 8080:8080 lwplaps/bootdocker:1

Github actions process

The below steps are already automated using github actions

prequsites

create the below secrets in your repository settings with your personal docker hub values

DOCKER_PASSWORD DOCKER_USERNAME

update the github actions workflow file with tyour respective docker repo details

***line 40 ***

    tags: <yourvalue>/bootdocker:${{ github.run_id }}

• Build executable jar file
• Build Docker image