Tips to reduce size of docker images

[a4xrbj1]

@raragao

So, in the end, I’m using a small image of node to run my app. No Meteor installed there.

Sounds great, do you have an estimate as to what the size difference would be otherwise? To give it some context?

[superfail]

@a4xrbj1

Sounds great, do you have an estimate as to what the size difference would be otherwise? To give it some context?

@a4xrbj1 In my case, Meteor is roughly 2GB after installing packages. Node’s binary is 80MB.

[superfail]

@superfail

One thing I am not really content with is the time it takes to build these images and the size of the resulting image.

Using buildx and copying files in stages I managed to get good layer caching. First build takes around 8 minutes on GitHub Actions, and “building” from cache takes <10s.

[raragao]

Same size approximately. 200MB in the registry.

[jacoatvatfree]

Could you perhaps share the applicable parts of your github actions script, I would love to reduce our build times and seems I can learn a lot from what you’ve accomplished.

[kheang]

this thread helped me, thanks.

[superfail]

@superfail

The final image is 1GB, and the intermediate “build” image is 4GB. It seems the intermediate “build” image has roughly 2 copies of the node_modules dependencies in src/node_modules (meteor npm clean-install), and bundle/programs/server/npm/node_modules (cd bundle/programs/server && meteor npm install), and the .meteor folder is gigantic (~1.6GB of packages and 400MB of package metadata). Is there anything one can do about this?

Instead of

RUN cd dist/bundle/programs/server && \
  meteor npm install

Could one maybe use

RUN cp -rl src/node_modules dist/bundle/programs/server/node_modules && \
  cd dist/bundle/programs/server && \
  meteor npm prune --production

with -l for hard links?

Or are dependencies in src/package.json and dist/bundle/programs/server/ different?

I assume one does not need

RUN cd dist/bundle/programs/server && \
  meteor npm install --production