Unicorn -> Puma

Gemfile

@@ -17,8 +17,8 @@ gem 'deep_cloneable'
 
 gem 'warden', git: 'https://github.com/hassox/warden.git', branch: 'master'
 
-# Use Unicorn as the app server
+# Use Puma as the app server
-gem 'unicorn'
+gem 'puma'
 
 # serializer
 gem 'active_model_serializers'

Gemfile.lock

@@ -450,7 +450,6 @@ GEM
       activerecord
       kaminari-core (= 1.1.1)
     kaminari-core (1.1.1)
-    kgio (2.11.2)
     launchy (2.4.3)
       addressable (~> 2.3)
     letter_opener (1.6.0)
@@ -558,6 +557,7 @@ GEM
       byebug (~> 10.0)
       pry (~> 0.10)
     public_suffix (3.0.2)
+    puma (3.12.0)
     rack (2.0.5)
     rack-handlers (0.7.3)
       rack
@@ -607,7 +607,6 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
     rainbow (3.0.0)
-    raindrops (0.19.0)
     rake (12.3.1)
     rb-fsevent (0.10.3)
     rb-inotify (0.9.10)
@@ -764,9 +763,6 @@ GEM
       unf_ext
     unf_ext (0.0.7.5)
     unicode-display_width (1.4.0)
-    unicorn (5.4.1)
-      kgio (~> 2.6)
-      raindrops (~> 0.7)
     validate_email (0.1.6)
       activemodel (>= 3.0)
       mail (>= 2.2.5)
@@ -863,6 +859,7 @@ DEPENDENCIES
   prawn_rails
   premailer-rails
   pry-byebug
+  puma
   rack-handlers
   rack-mini-profiler
   rails
@@ -891,7 +888,6 @@ DEPENDENCIES
   timecop
   turbolinks
   typhoeus
-  unicorn
   vcr
   warden!
   web-console

config/puma.rb

@@ -0,0 +1,56 @@
+# Puma can serve each request in a thread from an internal thread pool.
+# The `threads` method setting takes two numbers: a minimum and maximum.
+# Any libraries that use thread pools should be configured to match
+# the maximum value specified for Puma. Default is set to 5 threads for minimum
+# and maximum; this matches the default thread size of Active Record.
+#
+threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }
+threads threads_count, threads_count
+
+# Specifies the `port` that Puma will listen on to receive requests; default is 3000.
+#
+port        ENV.fetch("PORT") { 3000 }
+
+# Specifies the `environment` that Puma will run in.
+#
+environment ENV.fetch("RAILS_ENV") { "development" }
+
+# Specifies the number of `workers` to boot in clustered mode.
+# Workers are forked webserver processes. If using threads and workers together
+# the concurrency of the application would be max `threads` * `workers`.
+# Workers do not work on JRuby or Windows (both of which do not support
+# processes).
+#
+# workers ENV.fetch("WEB_CONCURRENCY") { 2 }
+
+# Use the `preload_app!` method when specifying a `workers` number.
+# This directive tells Puma to first boot the application and load code
+# before forking the application. This takes advantage of Copy On Write
+# process behavior so workers use less memory. If you use this option
+# you need to make sure to reconnect any threads in the `on_worker_boot`
+# block.
+#
+# preload_app!
+
+# If you are preloading your application and using Active Record, it's
+# recommended that you close any connections to the database before workers
+# are forked to prevent connection leakage.
+#
+# before_fork do
+#   ActiveRecord::Base.connection_pool.disconnect! if defined?(ActiveRecord)
+# end
+
+# The code in the `on_worker_boot` will be called if you are using
+# clustered mode by specifying a number of `workers`. After each worker
+# process is booted, this block will be run. If you are using the `preload_app!`
+# option, you will want to use this block to reconnect to any threads
+# or connections that may have been created at application boot, as Ruby
+# cannot share connections between processes.
+#
+# on_worker_boot do
+#   ActiveRecord::Base.establish_connection if defined?(ActiveRecord)
+# end
+#
+
+# Allow puma to be restarted by `rails restart` command.
+plugin :tmp_restart

config/unicorn.rb

@@ -1,105 +0,0 @@
-# Sample verbose configuration file for Unicorn (not Rack)
-#
-# This configuration file documents many features of Unicorn
-# that may not be needed for some applications. See
-# http://unicorn.bogomips.org/examples/unicorn.conf.minimal.rb
-# for a much simpler configuration file.
-#
-# See http://unicorn.bogomips.org/Unicorn/Configurator.html for complete
-# documentation.
-
-# Use at least one worker per core if you're on a dedicated server,
-# more will usually help for _short_ waits on databases/caches.
-worker_processes 2
-
-# Since Unicorn is never exposed to outside clients, it does not need to
-# run on the standard HTTP port (80), there is no reason to start Unicorn
-# as root unless it's from system init scripts.
-# If running the master process as root and the workers as an unprivileged
-# user, do this to switch euid/egid in the workers (also chowns logs):
-# user "unprivileged_user", "unprivileged_group"
-
-# Help ensure your application will always spawn in the symlinked
-# "current" directory that Capistrano sets up.
-
-# listen on both a Unix domain socket and a TCP port,
-# we use a shorter backlog for quicker failover when busy
-listen "127.0.0.1:3000", :tcp_nopush => true
-
-timeout 60
-
-# By default, the Unicorn logger will write to stderr.
-# Additionally, ome applications/frameworks log to stderr or stdout,
-# so prevent them from going to /dev/null when daemonized here:
-
-# combine Ruby 2.0.0dev or REE with "preload_app true" for memory savings
-# http://rubyenterpriseedition.com/faq.html#adapt_apps_for_cow
-preload_app true
-GC.respond_to?(:copy_on_write_friendly=) and
-  GC.copy_on_write_friendly = true
-
-# Enable this flag to have unicorn test client connections by writing the
-# beginning of the HTTP headers before calling the application.  This
-# prevents calling the application for connections that have disconnected
-# while queued.  This is only guaranteed to detect clients on the same
-# host unicorn runs on, and unlikely to detect disconnects even on a
-# fast LAN.
-check_client_connection false
-
-# local variable to guard against running a hook multiple times
-run_once = true
-
-before_fork do |server, worker|
-  # the following is highly recomended for Rails + "preload_app true"
-  # as there's no need for the master process to hold a connection
-  defined?(ActiveRecord::Base) and
-    ActiveRecord::Base.connection.disconnect!
-
-  # Occasionally, it may be necessary to run non-idempotent code in the
-  # master before forking.  Keep in mind the above disconnect! example
-  # is idempotent and does not need a guard.
-  if run_once
-    # do_something_once_here ...
-    run_once = false # prevent from firing again
-  end
-
-  # The following is only recommended for memory/DB-constrained
-  # installations.  It is not needed if your system can house
-  # twice as many worker_processes as you have configured.
-  #
-  # # This allows a new master process to incrementally
-  # # phase out the old master process with SIGTTOU to avoid a
-  # # thundering herd (especially in the "preload_app false" case)
-  # # when doing a transparent upgrade.  The last worker spawned
-  # # will then kill off the old master process with a SIGQUIT.
-  old_pid = "#{server.config[:pid]}.oldbin"
-  if old_pid != server.pid
-    begin
-      sig = (worker.nr + 1) >= server.worker_processes ? :QUIT : :TTOU
-      Process.kill(sig, File.read(old_pid).to_i)
-    rescue Errno::ENOENT, Errno::ESRCH
-    end
-  end
-  #
-  # Throttle the master from forking too quickly by sleeping.  Due
-  # to the implementation of standard Unix signal handlers, this
-  # helps (but does not completely) prevent identical, repeated signals
-  # from being lost when the receiving process is busy.
-  sleep 1
-end
-
-after_fork do |server, worker|
-  # per-process listener ports for debugging/admin/migrations
-  # addr = "127.0.0.1:#{9293 + worker.nr}"
-  # server.listen(addr, :tries => -1, :delay => 5, :tcp_nopush => true)
-
-  # the following is *required* for Rails + "preload_app true",
-  defined?(ActiveRecord::Base) and
-    ActiveRecord::Base.establish_connection
-
-  # if preload_app is true, then you may also want to check and
-  # restart any other shared sockets/descriptors such as Memcached,
-  # and Redis.  TokyoCabinet file handles are safe to reuse
-  # between any number of forked children (assuming your kernel
-  # correctly implements pread()/pwrite() system calls)
-end