Allow disabling rbenv and rvm in Ruby containers

[jarrodldavis]

• VSCode Version: 1.52.1
• Local OS Version: macOS Big Sur 11.1
• Name of Dev Container Definition with Issue: ruby, ruby-rails

Steps to Reproduce:

1. Generate a new Ruby on Rails app
2. Add ruby-rails development container definition
3. Reopen folder in container
4. Open a terminal and cd into the workspace directory (e.g. cd . or cd /workspace from a new Integrated Terminal)
5. Observe that rvm complains about the Ruby version specified in the Gemfile isn't installed, even though the development container specifically has (the correct version of) Ruby installed (see Disable RVM nag warning about a Ruby version not being installed #690).

Why are rbenv and rvm installed on Ruby development containers? We can already select the version of Ruby we want installed by using a particular Docker image tag, so there's no need for a Ruby version manager; they generate unnecessary noise and are difficult to remove from the pre-built containers. At the very least, there should be a mechanism to conditionally prevent loading the rvm and rbenv initialization scripts using an environment variable.

[Chuxel]

These were not in the containers originally in the containers, but developers requested them be added so they can take advantage of the related config files. So, removing them is not ideal.

That said, we can, however, "eat" these messages and prevent them from appearing or allow disabling them as you mention.

[Chuxel]

This ENV based to disable rbenv / rvm based on an environment variable would also apply to the codespaces-linux image.

[csutter]

This is also causing issues with the Ruby VS Code extension for me, which seems to detect rbenv/rvm being present and tries to load Ruby through them (instead of using the container's system Ruby): Required ruby-3.0.2 is not installed.

I'm moving towards using leaner custom devcontainer Dockerfiles based directly off the upstream ecosystem images (e.g. ruby:3, because the "kitchen sink" approach of these official VS Code images doesn't really work for me personally. Having the ability to more aggressively disable a lot of this stuff might tempt me back 😃

[slaytanic]

This is also causing issues with the Ruby VS Code extension for me, which seems to detect rbenv/rvm being present and tries to load Ruby through them (instead of using the container's system Ruby): Required ruby-3.0.2 is not installed.

I had the same issue and solved it by adding RUN rm /etc/profile.d/rvm.sh to my Dockerfile

[simmerz]

I've just rebuilt my container today and it's now forcing me to use rvm. Any attempt at bundling puts things into /usr/local/rvm/* - the above workaround no longer appears to work.

[Chuxel]

//cc @samruddhikhandale Is this potentially related to the migration to https://github.com/devcontainers/features and https://github.com/devcontainers/images ?

[samruddhikhandale]

Yes, looks related to the migration. We are now setting "GEM_HOME": "/usr/local/rvm/gems/default" in Ruby Feature here which is why gems get installed in usr/local/rvm/* with bundling.

Any attempt at bundling puts things into /usr/local/rvm/*

@simmerz Could you try unsetting GEM_HOME ? It should help fix the issue. 😄

[simmerz]

Unfortunately, unsetting GEM_HOME results in the following RUN gem install rails line failing in the Dockerfile.

That's if I add a line like ENV GEM_HOME "" above the first gem install.

If I RUN unset GEM_HOME it still looks for things in the rvm path when my post create command runs.

[samruddhikhandale]

I was running the commands from within the container, hence there were no permission issues. However, in your case looks like the dockerfile and postCreateCommand both are trying to install gems and fails due to permissions. Also, looks like the dockerfile is run by root and postCreateCommand by the remoteUser. Hence, the errors.

I tried recreating your scenario with ruby definition and this worked without errors.

ARG VARIANT="3.1-bullseye"
FROM mcr.microsoft.com/vscode/devcontainers/ruby:0-${VARIANT}

ENV GEM_HOME="/home/vscode/.gems" # where the gems will be installed (by default)
ENV GEM_PATH="${GEM_HOME}:${GEM_PATH}" # provides the locations where gems can be found.
RUN gem install rails

# Changing ownership so that the postCreateCommand can install gems with permission issues.
RUN chown -R vscode:vscode ${GEM_HOME} \ 
    && chmod -R g+w ${GEM_HOME} \
    && find ${GEM_HOME} -type d | xargs -n 1 chmod g+s

...

\\ ...
	"postCreateCommand": "gem install rack",
	"remoteUser": "vscode"
\\ ...

Gems are installed in specified GEM_HOME without any errors with the above modifications.

Let me know if this works.