Give `railway run` a specific Dockerfile

[gabedealmeida]

Often, you have different Dockerfiles depending on your application's environment, i.e., one for development and another for production. Currently, when running railway run, railway picks up only the one named Dockerfile and not something like Dockerfile.dev. It would be awesome if the user could choose the specific Dockerfile that railway run should use :)

[ndneighbor]

Interesting use-case, if you don't mind sharing, what happens to be different in the dev env rather than the production env.

We have thought that env var separation would be sufficient but would appreciate more information on the use-case.

[jboulter11]

Wanted to offer some insight to my use case for this:

I am using two dockerfiles temporarily because I'm currently on a swift 5.5 image but I haven't found a working swift 5.5 image that works for both M1 macs and x86 CI machines. Looks like they're putting out images that will work on both for Swift 5.6 but my deps aren't updated yet. I tried to switch my FROM statements based on an ENV but got an error, so I assumed it wasn't something I could do. Thus, was born Dockerfile.local.

[Milo123459]

this functionality was dropped