创建一个包含预安装的Spring Boot依赖项的Docker映像

Question

I have a spring-boot java application build with gradle, run by gitlab CI on gitlab.com that works just fine. But every time the CI run, it takes so much time to download dependencies (because I'm using gitlab shared-runner from gitlab.com which is docker-auto-scale runner and it doesn't cache anything for the next run).

My idea is create a docker image base on docker:latest (because build jobs needs to interact with docker daemon while running) and pre-install or add gradle caches to the image so that images contains all dependencies that my app needs and when the CI run, it doesn't need to re-download dependencies.

Has anyone done it before?

Answer 1

I had the exact idea as you did, but for Maven. During the docker image build, I copy my project files in the image and run mvn clean install and upload it to my gitlab registry.

CI pipeline execution time is considerably reduced.

But you of course need to do this everytime you have new dependencies, or at least when there is a large difference between what is already in the cache and the dependencies required by your app.