I've added a simple repo that recreates this issue: https://github.com/cgreening/docker-cache-problem
We have a very simple Dockerfile.
To speed up our builds we're using the --cache-from directive and using a previous build as a cache.
We're seeing some weird behaviour where if the files have not changed the lines after the COPY line are not being run.
RUN yarn && yarn build
Does not seem to get executed so when the application tries to start node_modules is missing.
FROM node
RUN mkdir /app
COPY . /app
WORKDIR /app
RUN yarn && yarn build
ENTRYPOINT ["yarn", "start"]
We're deploying to Kubernetes but I can pull the image locally and see that the files are missing:
# docker run -it --entrypoint /bin/bash gcr.io/XXXXX
root@3561a9cdab6e:/app# ls
DEVELOPING.md Dockerfile Makefile README.md admin-tools app.dev.yaml jest.config.js package.json src tailwind.config.js tools tsconfig.json tslint.json yarn.lock
root@3561a9cdab6e:/app#
Edit:
I've managed to recreate the problem outside of our build system.
Initial build:
DOCKER_BUILDKIT=1 docker build -t gcr.io/XXX/test:a . --build-arg BUILDKIT_INLINE_CACHE=1
docker push gcr.io/XXX/test:a
All works - node_modules and build folder are there:
Clean up docker as if we starting from scratch like on the build system
docker system prune -a
Do another build:
DOCKER_BUILDKIT=1 docker build -t gcr.io/XXX/test:b . --cache-from gcr.io/XXX/test:a --build-arg BUILDKIT_INLINE_CACHE=1
docker push gcr.io/XXX/test:a
Everything is still fine.
Clean up docker as if we starting from scratch like on the build system
docker system prune -a
Do a third build:
DOCKER_BUILDKIT=1 docker build -t gcr.io/XXX/test:c . --cache-from gcr.io/XXX/test:b --build-arg BUILDKIT_INLINE_CACHE=1
Files are missing!
docker run -it --entrypoint /bin/bash gcr.io/topo-wme-dev-d725ec6e/test:c
root@d07f6f1d3b12:/app# ls
DEVELOPING.md Dockerfile Makefile README.md admin-tools app.dev.yaml coverage jest.config.js package.json src tailwind.config.js tools tsconfig.json tslint.json yarn.lock
No node_modules or build folder.