Running Rails on Unicorn via Pow, is it possible to know what port Unicorn is running on?

Question

In my Ruby on Rails dev environment, I am starting Rails and Unicorn via Foreman in the typical way:

(Procfile:)

web: bundle exec unicorn -p $PORT -c ./config/unicorn.rb

I am also running Pow. But not as a webserver. I'm just using Pow to direct http requests from mydomain.dev (port 80) to the port Unicorn is listening on.

You can do this by creating a pow file (mydomain.dev) containing the port number Unicorn is running on.

Given this setup, is it possible in my rails code to know what the port I started Unicorn on?

I'm only wanting to know this in my dev environment, it's not a production issue.

In my Rails code, I've tried a few different things, but none of them work:

• Unicorn::Configurator::RACKUP[:port] - returned nothing
• Rails::Server.new.options[:Port] - doesn't exist in Rails 4

• Rack::Server.new.options[:Port] - returns default rack port (9292) not the one configured for this rack instance.

  Is there a way to get the current rack instance from rails?

• request.port - returns 80, which is the port that Pow is listening on. Pow is routing http traffic to Unicorn, which is on a different port.

None of these give me the port that Unicorn is running on.

Any ideas?

EDIT If you're wondering why I want to know this, it's because in my dev environment, I'm trying to dynamically create configuration files for Pow, so I can route http requests to Unicorn on the correct port.

Answer 1

If you're responding to a request in a controller or view, use the request object - this should work, although you say it does not:

request.port

If you're in an initialiser :

Rails::Server.new.options[:Port]

How to find the local port a rails instance is running on?

Answer 2

You should just be able to access it via ENV['PORT'], given it's value has been set to the $PORT environment variable.

Answer 3

Probably a bad idea, but whatever:

uport = `netstat -n --listening --tcp -p | grep unicorn | sed 's/.*:\([0-9]*\) .*/\1/'`

Answer 4

I've sort of found a way to do this.

1. Create separate config files for Unicorn. unicorn.development.rb and unicorn.test.rb
2. Install the dotenv-rails gem

3. Inside my unicorn config files, do something like this: # unicorn.development.rb:

   require "dotenv"
   Dotenv.load(
     "./.env.local",
     "./.env.development",
     "./.env"
   )
   
   if ENV['UNICORN_PORT'].nil?
     throw 'UNICORN_PORT not set in environment!'
   end
   
   worker_processes 3
   timeout 30
   preload_app true
   
   listen ENV['UNICORN_PORT'], backlog: 64
   
   ... rest of unicorn config...
   
   
   
   
   # unicorn.testing.rb:
   
   require "dotenv"
   Dotenv.load(
     "./.env.local",
     "./.env.testing",
     "./.env"
   )
   
   if ENV['UNICORN_PORT'].nil?
     throw 'UNICORN_PORT not set in environment!'
   end
   
   worker_processes 3
   timeout 30
   preload_app true
   
   listen ENV['UNICORN_PORT'], backlog: 64
   
   ... rest of unicorn config...
   

4. In my .env.development and .env.testing environment files, set the UNICORN_PORT environment variable

5. Make sure you use the correct Unicorn config file to start the app. This can be done by using separate Procfiles for dev and testing.

   # Procfile.dev
   web: bundle exec unicorn -c ./config/unicorn.development.rb
   
   # Procfile.testing
   web: bundle exec unicorn -c ./config/unicorn.testing.rb
   

This appears to mostly work, but is not without it's issues...