How to Reduce Docker Image

The following are the methods by which we can achieve docker image optimization.

1. Using distroless/minimal base images

2. Multistage builds

3. Minimizing the number of layers

4. Understanding caching

5. Using Dockerignore

6. Keeping application data elsewhere

🔹Create One Ec2 instance i.e t2 micro.

🔹First Clone this project:-

git clone https://github.com/kumarvimal349/springboot-crud-k8s.git

🔹Command :- ls

🔹Install docker-engine on your Instance:-

Command:-

apt-get install docker.io -y 
apt-get update -y

🔹Build Dockerfile ( without MultiStage):-

FROM openjdk:8
EXPOSE 8080
ADD target/springboot-crud-k8s.jar springboot-crud-k8s.jar
ENTRYPOINT ["java","-jar","/springboot-crud-k8s.jar"]

Then run command :- docker build . -t spring-app

🔹Command :- Docker Images

you see images size is 565MB which is very high, So we can reduce this image size..

🔹Build Dockerfile ( with MultiStage):-

############# BASE IMAGE #################################
FROM openjdk:8 as build
WORKDIR /app
COPY . /app
############# MULTI STAGE IMAGE #################################
FROM openjdk:8-jdk-alpine as main
COPY --from=build /app /
EXPOSE 8080
ADD target/springboot-crud-k8s.jar springboot-crud-k8s.jar
ENTRYPOINT ["java","-jar","/springboot-crud-k8s.jar"]

Then run command :- docker build . -t spring-app-multistage

🔹Command :- Docker Images

Image size is reduced to 217 MB..

I hope this helps! Let me know if you have any questions.

I am Vimal kumar, Please do follow me here and support #devOps #trainwithshubham #github #devopscommunity #devops #cloud #devoparticles #docker #kubernetes #aws #kubeWeek

Vimal Kumar

Shubham Londhe