Foreman/Puma isn't using the specified port in dev env

Question

I set the port as 3000 in my application.yml (figaro managing env variables) rails s uses port 3000 but when I run foreman start (as recommended by Her

Answer 1

Use a .foreman file with:

port: 3000

or a .env file with:

PORT=3000

Either one should work, then you can just use foreman start

Answer 2

port ENV['PORT'] || 3000

This line says that you will attempt to use ENV['PORT'] first and if that doesn't exist, you will fall back to using 3000 as the port number. So are you defining PORT environment variable anywhere prior to foreman starting? config/application.yml environment variables only will be loaded after the rails server starts, so it's no use defining port number here.

You can try adding

PORT=3000 in .env file in the root of the project directory.

Source: https://devcenter.heroku.com/articles/getting-started-with-rails5#procfile

Answer 3

Mystery on the puma port solved.

Put this print in your config/puma.rb

Then you'll see that somehow the port is mysteriously set to 5000 even though it is not in your ENV.

Fix at bottom.

puma_port = ENV['PORT'] || 3000
puts "ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ"
puts "puma_port is #{puma_port}"
puts "ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ”

That prints out

16:49:28 web.1  | ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
16:49:28 web.1  | puma_port is 5000
ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ

Then place this line in your Procfile (not the one you use for Heroku). I've got one called Procfile.dev

web: PORT=3000 bundle exec puma -C config/puma.rb

And I run it with this command:

foreman start -f Procfile.dev