Switch from Thin to Puma

* Commit database.yml to git to setup pool size
* Set `PORT` var, make sure to update your local `.env`

https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server

Closes: #286

Author: antonfefilov

.env.example

@@ -1,6 +1,9 @@
 # Specify assets server host name, eg.: d2oek0c5zwe48d.cloudfront.net
 # ASSET_HOST=d2oek0c5zwe48d.cloudfront.net
 
+# Port to serve application
+PORT=5000
+
 # current environment:
 RACK_ENV=development
 

.gitignore

@@ -4,7 +4,6 @@ log/*.log
 tmp/*
 coverage/*
 rerun.txt
-config/database.yml
 doc/**/*
 vendor/bundle
 vendor/cache

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Switch web server from [Thin](https://github.com/macournoyer/thin) to [Puma](https://github.com/puma/puma)
 - Update [Uglifier](https://github.com/lautis/uglifier) version up to 2.7.2
 - Add [Rubocop-Rspec](https://github.com/nevir/rubocop-rspec) for reporting violations of Ruby style guide in specs
 - Add [Slim-Lint](https://github.com/sds/slim-lint) for reporting violations of Ruby style guide in `.slim` templates

Gemfile

@@ -31,7 +31,7 @@ gem "kaminari"
 gem "responders"
 gem "rollbar", "~> 0.10.3"
 gem "seedbank"
-gem "thin"
+gem "puma"
 gem "pundit"
 gem "rack-canonical-host"
 

Gemfile.lock

@@ -109,7 +109,6 @@ GEM
     columnize (0.8.9)
     crack (0.4.2)
       safe_yaml (~> 1.0.0)
-    daemons (1.1.9)
     database_cleaner (1.3.0)
     debug_inspector (0.0.2)
     debugger-linecache (1.2.0)
@@ -131,7 +130,6 @@ GEM
       launchy (~> 2.1)
       mail (~> 2.2)
     erubis (2.7.0)
-    eventmachine (1.0.7)
     execjs (2.6.0)
     factory_girl (4.5.0)
       activesupport (>= 3.0.0)
@@ -210,6 +208,7 @@ GEM
       slop (~> 3.4)
     pry-rails (0.3.2)
       pry (>= 0.9.10)
+    puma (2.13.4)
     pundit (1.0.0)
       activesupport (>= 3.0.0)
     quiet_assets (1.0.2)
@@ -353,10 +352,6 @@ GEM
     therubyracer (0.12.1)
       libv8 (~> 3.16.14.0)
       ref
-    thin (1.6.1)
-      daemons (>= 1.0.9)
-      eventmachine (>= 1.0.0)
-      rack (>= 1.0.0)
     thor (0.19.1)
     thread_safe (0.3.5)
     tilt (1.4.1)
@@ -418,6 +413,7 @@ DEPENDENCIES
   metamagic
   pg
   pry-rails
+  puma
   pundit
   quiet_assets
   rack-canonical-host
@@ -442,7 +438,6 @@ DEPENDENCIES
   spring
   spring-commands-rspec
   therubyracer
-  thin
   uglifier (>= 2.7.2)
   web-console (~> 2.0)
   webmock

Procfile

@@ -1 +1 @@
-web: bundle exec rails server thin -p $PORT -e $RACK_ENV
+web: bundle exec puma -C config/puma.rb

README.md

@@ -28,7 +28,7 @@ It's based on Rails 4 and Ruby 2.2.3.
 
 ## Development Gems
 
-* [Thin](https://github.com/macournoyer/thin) as Rails web server
+* [Puma](https://github.com/puma/puma) as Rails web server
 * [Foreman](https://github.com/ddollar/foreman) for managing development stack with Procfile
 * [Letter Opener](https://github.com/ryanb/letter_opener) for opening mail in the browser instead of sending it
 * [Bullet](https://github.com/flyerhzm/bullet) for detecting N+1 queries and unused eager loading

config/database.yml

@@ -0,0 +1,19 @@
+defaults: &defaults
+  adapter: postgresql
+  encoding: unicode
+  min_messages: warning
+  timeout: 5000
+  pool: <%= [ENV.fetch("MAX_THREADS", 5), ENV.fetch("DB_POOL", 5)].max %>
+
+development:
+  database: application_dev
+  <<: *defaults
+
+test:
+  database: application_test
+  <<: *defaults
+
+production: &deploy
+  <<: *defaults
+
+staging: *deploy

config/database.yml.example

@@ -0,0 +1,13 @@
+workers ENV.fetch("WEB_CONCURRENCY", 2).to_i
+threads_count = ENV.fetch("MAX_THREADS", 5).to_i
+threads threads_count, threads_count
+
+rackup DefaultRackup
+port ENV.fetch("PORT", 5000)
+environment ENV.fetch("RACK_ENV", "development")
+
+preload_app!
+
+on_worker_boot do
+  ActiveRecord::Base.establish_connection
+end