Do not hardcode port in config.ru

[ntalbott]

Proposed solution for #49, just removes the hard coded port in config.ru.

[bmaland]

Whats the point of duplicating 108ccc1 in #65 ..? My pull request also runs on port 4000 by default, and fixes serve's inability to run on Heroku Cedar.

[ntalbott]

@bmaland, I actually created this before I saw your more comprehensive patch. That said, the question in this thread has to be answered either way, as removing the hard coding of port 4000 in config.ru does change functionality and I need to understand the desired behavior before I can determine whether that's OK.

[bmaland]

I think the intended logic is port 3000 for Rails apps, and port 4000 for everything else except when overridden by the command line flag (or ENV["PORT"] for Heroku).

[jlong]

Yup that's correct. Any other issues @ntalbott?

[jlong]

Mmmm. So the problem with this is that regular Rack apps currently started on 3000 with Serve. The port override in config.ru makes generated Serve apps startup on port 4000 which matches the existing command line functionality when using Serve in "unstructured" mode.

There's not an easy way to detect Serve rack apps, so I'm not sure of a good solution.

[ntalbott]

After looking deeply at Rack, it seems that it simply isn't possible to achieve the ability to specify a port in config.ru and allow that port to be overridden using the command line. This is due to the way Rack/rackup process options, and wouldn't be a simple fix on that side. Thus I'm going to punt on this and say that if one wants to override the port that's in config.ru, they have to delete the comment that forces the app onto 4000.

[jlong]

Agreed.

[bmaland]

Right, if this is the intended behavior then the docs and the output from "serve --help" would have to be updated, since the functionality described there simply doesn't work.

[ntalbott]

Hmmm, you mean in terms of the --port option? Documenting this nuance is going to be tricky - any ideas @jlong?

[bmaland]

Yeah, both serve --help and http://get-serve.com/documentation/usage are currently misleading about this feature.

I'm still not sure why breaking the functionality of the serve executable is preferred over having config.ru have a port set by default - isn't the most common use case to run serve from the command line?