Re: tramp-container doesn't follow `ENV PATH` in docker file

[Michael Albinus]

ParetoOptimalDev <pareto.optimal@mailfence.com> writes:

Hi,

> I made some progress and I figured out how to get the `ENV PATH` value
> with a weird hacky feeling method:

Just for the records: I have seen also your first message. Since the
times are busy, I have postponed to answer. However, I agree we need to
do something in this area.

> #+begin_src sh
> docker run -t haskell bash -c 'env PATH=$PATH bash -c "echo $PATH"'
> #+end_src
>
> #+RESULTS:
> :
> /root/.cabal/bin:/root/.local/bin:/opt/ghc/9.4.2/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
>
> I tried to modify the `tramp-docker-method` in `tramp-methods` to
> utilize the above command but it didn't work.
>
> Here was my attempt:
>
> (add-to-list 'tramp-methods
>               `(,tramp-docker-method
>                 (tramp-login-program ,tramp-docker-program)
>                 (tramp-login-args (("exec")
>                                    ("-it")
>                                    ("-u" "%u")
>                                    ("%h")
>                                  ("%l")
>                                  ))
>               (tramp-direct-async (,tramp-default-remote-shell "-c"))
>                 (tramp-remote-shell ,tramp-default-remote-shell)
>                 (tramp-remote-shell-login ("-l"))
>                 (tramp-remote-shell-args ("-i" "-c" "'env
>               PATH=$PATH'"))))
>
> Can anyone help with this?

Well, where does $PATH come from? Should it be your local $PATH on the
machine you're calling docker?

Note, that your change wouldn't do anything. The $PATH on the docker
instance is computed in the remote shell, based on tramp-remote-path. If
you want to change something, it must be there.

This mechanism is questionable in general. There is already the Emacs
bug#61926, which asks for something else. This request is currently
pending (due to other prioritzed work); when I'll work on this I will
also take your request into account. If you like, you could also send a
message to that bug number, requesting proper changes for docker. Just
in case nobody forgets it.

Best regards, Michael.