Merge branch 'rs-bootsnap' into 'master'

Add Bootsnap to all environments to reduce application startup time

Closes #33081

See merge request !12034

Gemfile

@@ -2,6 +2,7 @@ source 'https://rubygems.org'
 
 gem 'rails', '4.2.8'
 gem 'rails-deprecated_sanitizer', '~> 1.0.3'
+gem 'bootsnap', '~> 1.0.0'
 
 # Responders respond_to and respond_with
 gem 'responders', '~> 2.0'

Gemfile.lock

@@ -82,6 +82,8 @@ GEM
     bindata (2.3.5)
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
+    bootsnap (1.0.0)
+      msgpack (~> 1.0)
     bootstrap-sass (3.3.6)
       autoprefixer-rails (>= 5.2.1)
       sass (>= 3.3.4)
@@ -459,6 +461,7 @@ GEM
     minitest (5.7.0)
     mmap2 (2.2.6)
     mousetrap-rails (1.4.6)
+    msgpack (1.1.0)
     multi_json (1.12.1)
     multi_xml (0.6.0)
     multipart-post (2.0.0)
@@ -888,6 +891,7 @@ DEPENDENCIES
   benchmark-ips (~> 2.3.0)
   better_errors (~> 2.1.0)
   binding_of_caller (~> 0.7.2)
+  bootsnap (~> 1.0.0)
   bootstrap-sass (~> 3.3.0)
   brakeman (~> 3.6.0)
   browser (~> 2.2)

config/boot.rb

@@ -4,3 +4,15 @@ require 'rubygems'
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
 
 require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+
+# Default Bootsnap configuration from https://github.com/Shopify/bootsnap#usage
+require 'bootsnap'
+Bootsnap.setup(
+  cache_dir:            'tmp/cache',
+  development_mode:     ENV['RAILS_ENV'] == 'development',
+  load_path_cache:      true,
+  autoload_paths_cache: true,
+  disable_trace:        false,
+  compile_cache_iseq:   true,
+  compile_cache_yaml:   true
+)