TL;DR; the "official Docker image test suite" run by Docker requires the CMD to be overridden when an image has a shell (as the Alpine Traefik).
With v2.0-alpha6, the Traefik CLI accepts non flags options, which leads to issues.
This change is only alpine, and delegate to the main shell the user-provided CMD if it is not a command recognized by traefik.
So the following exemple works:
# print Traefik version
docker run --rm traefik:<tag> version
# print Traefik help about healthcheck Traefik's command
docker run --rm traefik:<tag> healthcheck --version
# print "Hello world-<random number>-<random number>" with a message in the log that switched to shell
docker run --rm traefik:<tag> echo Hello world-$RANDOM-$RANDOM
Related to https://github.com/docker-library/official-images/pull/6106#issuecomment-503314187
TL;DR; the "official Docker image test suite" run by Docker requires the CMD to be overridden when an image has a shell (as the Alpine Traefik). With v2.0-alpha6, the Traefik CLI accepts non flags options, which leads to issues.
This change is only alpine, and delegate to the main shell the user-provided CMD if it is not a command recognized by
traefik.So the following exemple works:
Important: works with 1.7.12, but for 2.0, it requires https://github.com/containous/traefik/pull/4977 to be merged!