I’m getting some weird behavior from Docker and I can’t find it mentioned anywhere. It is skipping stages seemingly at random, even with multi-stage Dockerfiles that I’ve simply copy-pasted from forums around the net.
My dockerfile is:
FROM alpine as base RUN echo "1" # SKIPPED FROM base as mid RUN echo "2" FROM base as final RUN echo "3"
docker build -t test . --no-cache [+] Building 2.0s (7/7) FINISHED => [internal] load .dockerignore 0.0s => => transferring context: 34B 0.0s => [internal] load build definition from Dockerfile 0.0s => => transferring dockerfile: 143B 0.0s => [internal] load metadata for docker.io/library/alpine:latest 1.3s => CACHED [base 1/2] FROM docker.io/library/[email protected]:... 0.0s => [base 2/2] RUN echo "1" 0.3s => [final 1/1] RUN echo "3" 0.4s => exporting to image 0.0s => => exporting layers 0.0s => => writing image sha256:... 0.0s => => naming to docker.io/library/... 0.0s
What causes this?
Source: Docker Questions