Adds -w WORKDIR option to fig run.

[scottynomad]

Just wired up the ability to set the workdir when using fig run.

[aanand]

Nice job, but is there a compelling use case for passing -w rather than just setting working_dir in fig.yml?

(...other than that it's undocumented...)

[scottynomad]

Ah, I missed the undocumented working_dir in fig.yml. That will be useful! I just found myself looking for the command line switch a few times recently when debugging my container setups.

[d11wtq]

I'm generally in favour of supporting command line overrides for things in fig.yml, as long as the defaults don't require you to pass any specific command line flags.

[aanand]

While the current parameters for fig run (-d, -T, --rm, --no-deps) make sense to me as things you might want to change at runtime, I'm struggling to think of a common use case where you'd want to override the working dir without just going into fig.yml and changing it.

For that reason, I think I'm -1 on merging this, since the logical extension would be to support absolutely every docker run parameter, and that'll involve a lot of glue code.

[scottynomad]

That's fair. I'm glad to know about the fig.yml option!

[aanand]

@scooterXL I've documented it and everything 😏