rails: rails restart doesn't work with puma3

hey @sikachu @rubys try this https://github.com/chashmeetsingh/rails/blob/master/railties/lib/rails/tasks/restart.rake I got it working boohoo Still needs improvements

I made some progress on this.

We need to provide a restart command to Puma which it will use while restarting the server. The command will be bin/rails s.

Even after this, there is an issue with existing pid file present in tmp/pids/server.pid file. I think it’s okey to remove that file manually from Rails side when doing rails restart or rails dev:cache. But would like to hear more opinions if I am missing something. (cc @rafaelfranca, @kaspth )

I think we will need to make some changes to Puma also to correctly accept the restart command from Rails. I got it working locally and will make a PR shortly to Puma.

$ rails s
=> Booting Puma
=> Rails 5.0.0.beta3 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
"conf options"
Puma starting in single mode...
* Version 3.2.0 (ruby 2.3.0-p0), codename: Spring Is A Heliocentric Viewpoint
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://localhost:3000
Use Ctrl-C to stop
* Restarting...
["bin/rails", "s", {:close_others=>true, 31=>31}]
"----------"
=> Booting Puma
=> Rails 5.0.0.beta3 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
"conf options"
Puma starting in single mode...
* Version 3.2.0 (ruby 2.3.0-p0), codename: Spring Is A Heliocentric Viewpoint
* Min threads: 5, max threads: 5
* Environment: development
* Inherited tcp://localhost:3000
Use Ctrl-C to stop

`def restart! @config.run_hooks :on_restart, self

  if Puma.jruby?
    close_binder_listeners

    require 'puma/jruby_restart'
    JRubyRestart.chdir_exec(@restart_dir, restart_args)
  elsif Puma.windows?
    close_binder_listeners

    argv = restart_args
    Dir.chdir(@restart_dir)
    Kernel.exec(*argv)
  else
    redirects = {:close_others => true}
    @binder.listeners.each_with_index do |(l, io), i|
    ENV["PUMA_INHERIT_#{i}"] = "#{io.to_i}:#{l}"
    redirects[io.to_i] = io.to_i
    end

    argv = restart_args
    Dir.chdir(@restart_dir)
    argv += [redirects] if RUBY_VERSION >= '1.9'

    #--------------
    pid = File.read('tmp/pids/server.pid')
    system("kill -9 #{pid} && sleep 10 && rails dev:cache && sleep 5 && rails tmp:clear && rails s")
    #--------------
  end
end`

I did this still get the same error as rubys 😦

From the messages, it appears that the port is being inherited.

More generally:

• From a rails development perspective, the user starts the server in one terminal window and may return to that window occasionally to see status messages. It would be a desirable feature for the server to be restarted in that window.
• Puma has support for features like phased restart that are not needed in a Rails development environment. Given that Evan seems motivated to support this scenario, I would suggest that if additional functionality is required to make this work, that such be added to puma, perhaps as a configuration option.

I’ve opened a separate issue to track the puma changes required: https://github.com/puma/puma/issues/907