Use the PORT environment variable for rails server

[davidcornu]

Allow the server port to be set with the PORT environment variable.

• This has become somewhat of a standard on various platforms
• Would simplify setting a default port in development (which is currently only possible by either monkey-patching or using a custom script to start the server)

[senny]

can we wait with the helper extraction until it's needed in other cases as well. Once they're extracted it's harder to clean em up when tests get deleted or changed.

[senny]

This will need an entry in the CHANGELOG as well.

[davidcornu]

@senny done.

[rafaelfranca]

Is not PORT too generic? I mean, in a machine with a lot of services running what PORT means?

[davidcornu]

Is not PORT too generic? I mean, in a machine with a lot of services running what PORT means?

The PORT environment variable became a bit of a convention once Heroku started requiring apps to use it.

• Heroku: https://devcenter.heroku.com/articles/dynos#web-dynos
• Express: https://github.com/strongloop/express-example-app/blob/master/server.js#L4
• Cloud9: https://docs.c9.io/docs/writing-a-nodejs-app#section-a-simple-node-js-http-server
• Engine Yard: https://support.cloud.engineyard.com/hc/en-us/articles/205411878-Deploy-Your-Node-js-Application-on-Engine-Yard-Cloud#topic6
• Azure: https://azure.microsoft.com/en-us/documentation/articles/web-sites-nodejs-develop-deploy-mac/#_build-and-test-your-application-locally

[rafaelfranca]

😢 Heroku always creating weird conventions. cc @schneems

[schneems]

If Rails had set a convention before us, we would have followed it 😉

On Heroku it will help, but not that much. We already set this if you don't have a procfile: https://github.com/heroku/heroku-buildpack-ruby/blob/154fab366ff2a611893a825eff33d537d717a350/lib/language_pack/rails2.rb#L36.

I think we generally recommend against using $ rails s in production as it uses webrick by default. Though I guess you can specify $ rails s Puma, etc.

It looks like gunicorn for python supports $PORT: https://github.com/benoitc/gunicorn/blob/master/docs/source/2012-news.rst#0160--2012-11-19

All in all, it's a pretty simple patch and provide benefits. I'm 👍 . If issue arise from this I can own this minimal code path.

[rafaelfranca]

I don't like environment variables changing behavior, but yeah... it is already a convention.

[davidcornu]

🎉