Container support

[lanjoni]

Okay, we all know that it's not practical for anyone to have all the programming languages installed right? But, what if I had a flag stating that to execute, an alternative command must be executed, that is: a command to be executed in a specific programming language container?

Wow! It would be simply incredible, wouldn't it?

Well, this issue is open for exactly that! Comment here and let's discuss more or open your pull request!

[J0sueTM]

Please assign it to me! We've talked about approaches to this issue, so I could take the lead on it!

[J0sueTM]

Hey @lanjoni. I've done my research and a couple of tests, and I came to a possible solution, which implies on modifications to docker itself.

The library I'll be using is crystal-docker, which doesn't have support for socket based connections e.g: /run/containerd/containerd.sock. Since only TCP based connections are supported for now, a solution I came upon was to modify the startup of the docker daemoni in order to accept TCP connections, which unfortunately implies some security breaches could happen.

I also found this article that explains the benefits of making this change. Besides the security problems, the only backside is that everyone wanting to use the -d flag for docker images/containers, would need to enable remote access to docker.

What do you think about this? I'm open to ideas.

[lanjoni]

Hi @J0sueTM!

Perhaps the solution itself is somewhat simpler than running Crystal per container. Well, the advantage of using Crystal is that we can use an executable with the code already compiled.

The main point may be: we don't need a container to run Crystal but we need containers to run the resolutions of other programming languages. Perhaps it would be more practical not to worry about executing a container in Crystal to communicate with others, after all, the compiled one will be executed on the host and will have to upload containers and execute code from other programming languages, also validating the output of each code executed as it is already doing today.

What do you think about that?

[lanjoni]

Hey, the first PR for this case was merged on #15!

[lanjoni]

Some updates to do:

• Add support to --verbose flag on --docker
• Add support to -a (to add arguments instead stdin)

[J0sueTM]

Besides these necessary updates, we've found a couple of things that aren't related first hand to this PR, but still inflicts on it, which are:

• Refactor module Run. both functions run_test and run_docker have little differences, so an abstraction would be good
• Fix bug on first run. For some reason, if it's the first time a language is being pulled, it doesn't run the tests right away.
• Make output from shell commands visible. For example, it would be nice to show the docker pull command visual for the end user.
• Test some exotic languages that aren't in the list in lang/lang.json. Maybe add those on demand?