Add puma configuration to version control

We were using Capistrano's shared folder because it was the default
folder used by the capistrano-puma gem. However, it's easier to manage
it if it's under version control.

So we're moving the old `puma.rb` to `puma/development.rb`, and we use
the new `puma.rb` file for all environments except development. Anyone
installing CONSUL can change these files at will or change the specific
files for preproduction, production and staging environments.

config/deploy.rb

@@ -31,10 +31,7 @@ set :keep_releases, 5
 
 set :local_user, ENV["USER"]
 
-set :puma_restart_command, "bundle exec --keep-file-descriptors puma"
-set :puma_workers, 2
-set :puma_preload_app, true
-set :puma_init_active_record, true
+set :puma_conf, "#{release_path}/config/puma/#{fetch(:rails_env)}.rb"
 
 set :delayed_job_workers, 2
 set :delayed_job_roles, :background
@@ -48,6 +45,8 @@ set(:config_files, %w[
 set :whenever_roles, -> { :app }
 
 namespace :deploy do
+  Rake::Task["puma:check"].clear_actions
+
   before :starting, "rvm1:install:rvm"
   before :starting, "rvm1:install:ruby"
   before :starting, "install_bundler_gem"

config/puma.rb

@@ -1,15 +1,36 @@
-# ATTENTION: This file is only used to run puma on your development
-# machine. To configure puma on production environments, use the
-# `puma.rb` file in Capistrano's `shared` folder.
+#!/usr/bin/env puma
 
-# Puma can serve each request in a thread from an internal thread pool.
-# Default is set to 5 threads for minimum and maximum, matching the
-# default thread size of Active Record.
-threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }.to_i
-threads threads_count, threads_count
+rails_root = File.expand_path("../..", __FILE__)
 
-port        ENV.fetch("PORT") { 3000 }
-environment ENV.fetch("RAILS_ENV") { "development" }
+directory rails_root
+rackup "#{rails_root}/config.ru"
+environment "production"
 
-# Allow puma to be restarted by `rails restart` command.
-plugin :tmp_restart
+tag ""
+
+pidfile "#{rails_root}/tmp/pids/puma.pid"
+state_path "#{rails_root}/tmp/pids/puma.state"
+stdout_redirect "#{rails_root}/log/puma_access.log", "#{rails_root}/log/puma_error.log", true
+
+bind "unix://#{rails_root}/tmp/sockets/puma.sock"
+
+threads 0, 16
+workers 2
+preload_app!
+
+restart_command "bundle exec --keep-file-descriptors puma"
+
+on_restart do
+  puts "Refreshing Gemfile"
+  ENV["BUNDLE_GEMFILE"] = ""
+end
+
+before_fork do
+  ActiveRecord::Base.connection_pool.disconnect!
+end
+
+on_worker_boot do
+  ActiveSupport.on_load(:active_record) do
+    ActiveRecord::Base.establish_connection
+  end
+end

config/puma/development.rb

@@ -0,0 +1,11 @@
+# Puma can serve each request in a thread from an internal thread pool.
+# Default is set to 5 threads for minimum and maximum, matching the
+# default thread size of Active Record.
+threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }.to_i
+threads threads_count, threads_count
+
+port        ENV.fetch("PORT") { 3000 }
+environment "development"
+
+# Allow puma to be restarted by `rails restart` command.
+plugin :tmp_restart

config/puma/preproduction.rb

@@ -0,0 +1,5 @@
+#!/usr/bin/env puma
+
+_load_from File.expand_path("../../puma.rb", __FILE__)
+
+environment "preproduction"

config/puma/production.rb

@@ -0,0 +1,5 @@
+#!/usr/bin/env puma
+
+_load_from File.expand_path("../../puma.rb", __FILE__)
+
+environment "production"

config/puma/staging.rb

@@ -0,0 +1,5 @@
+#!/usr/bin/env puma
+
+_load_from File.expand_path("../../puma.rb", __FILE__)
+
+environment "staging"