The `CMD` command contains an invalid value

[vill]

https://github.com/evilmartians/ruby-on-whales/blob/b8c47dbee5ab46bb5e891fdb9b0f947f12d4ceed/example/.dockerdev/Dockerfile#L83

ls -lh /usr/bin/bash
ls: cannot access '/usr/bin/bash': No such file or directory

The correct value should be:

which bash
/bin/bash

[palkan]

Can you please tell your build args, such as RUBY_VERSION and DISTRO?

[vill]

# compose.yaml
RUBY_VERSION: '3.2.2'

# Dockerfile
ARG RUBY_VERSION
ARG DISTRO_NAME=bullseye

FROM ruby:$RUBY_VERSION-slim-$DISTRO_NAME

[palkan]

Thanks! And when do you this error, how to build the image? I've haven't seen this problem in any project (all based on this Dockerfile and having the same CMD line).

[vill]

I executed these commands inside the created container:

ls -lh /usr/bin/bash
ls: cannot access '/usr/bin/bash': No such file or directory

which bash
/bin/bash

I've haven't seen this problem in any project (all based on this Dockerfile and having the same CMD line).

You won't have any problems even if you specify this value for CMD

CMD ["/usr/bin/abracadabra"]

Perhaps the problem can be seen if you run this through docker and not compose.

[vill]

CMD is redefined for example here: https://github.com/evilmartians/ruby-on-whales/blob/b8c47dbee5ab46bb5e891fdb9b0f947f12d4ceed/example/.dockerdev/compose.yml#L53

[vill]

Why then is/bin/bash used here and not/usr/bin/bash?

https://github.com/evilmartians/ruby-on-whales/blob/b8c47dbee5ab46bb5e891fdb9b0f947f12d4ceed/example/dip.yml#L16-L19

[palkan]

CMD is redefined for example here

oh, I see; thanks for the explanation; yeah, we always use compose locally.

Why then is /bin/bash used here and not /usr/bin/bash?

Wish I knew 😄 I guess it was added originally to not depend on CMD (in case it has been redefined) and make this command always work.