When building Docker images with DOCKER_BUILDKIT=1, there is a very cool progress indicator but no command output. How do I see the command output to debug my build?
Have you tried --progress=plain?
Example:
FROM alpine
RUN ps aux
Relative output of DOCKER_BUILDKIT=1 docker build --progress=plain -t test_buildkit .:
#5 [2/2] RUN ps aux
#5 digest: sha256:e2e4ae1e7db9bc398cbcb5b0e93b137795913d2b626babb0f148a60017379d86
#5 name: "[2/2] RUN ps aux"
#5 started: 2019-04-19 09:02:58.922035874 +0000 UTC
#5 0.693 PID USER TIME COMMAND
#5 0.693 1 root 0:00 ps aux
#5 completed: 2019-04-19 09:02:59.721490002 +0000 UTC
#5 duration: 799.454128ms
👉 Also, check the very useful answer by @Cocowalla below about BUILDKIT_PROGRESS=plain
As well as using --progress=plain on the command line, you can also set an environment variable:
BUILDKIT_PROGRESS=plain
I find this particularly useful for CI builds, where I always want the full log.