Address already in use - bind(2) (Errno::EADDRINUSE)

Question

I am trying to deploy Rails app with the Puma web server. When trying to start Puma server with a config file bundle exec puma -C config/puma.rb I get an error

Answer 1

Found the script below in this github issue. Works great for me.

#!/usr/bin/env ruby
port = ARGV.first || 3000
system("sudo echo kill-server-on #{port}")

pid = `sudo lsof -iTCP -sTCP:LISTEN -n -P | grep #{port} | awk '{ print $2 }' | head -n 1`.strip
puts "PID: #{pid}"
`kill -9 #{pid}` unless pid.empty?

You can either run it in irb or inside a ruby file.

For the latter, create server_killer.rb then run it with ruby server_killer.rb