Better backend

.eslintrc.yml

@@ -0,0 +1,16 @@
+env:
+  browser: true
+  node: true
+  es6: true
+extends: 'eslint:recommended'
+globals:
+  Atomics: readonly
+  SharedArrayBuffer: readonly
+parserOptions:
+  ecmaFeatures:
+    jsx: true
+  ecmaVersion: 2018
+  sourceType: module
+plugins:
+  - react
+rules: {}

.gitignore

@@ -27,6 +27,7 @@ coverage
 
 # Ignore node_modules
 node_modules/
+false/
 
 # Generated js bundles
 /app/assets/javascripts/generated/*
@@ -36,6 +37,7 @@ latest.dump
 
 # Ignore application configuration
 /config/application.yml
+config/new_relic.yml
 /public/packs
 /public/packs-test
 /node_modules
@@ -52,4 +54,4 @@ package-lock.json
 .idea/
 
 #sitemap
-/public/sitemap.xml.gz
+/public/sitemap.xml.gz

Envfile

@@ -148,6 +148,8 @@ variable :TRENDING_TAGS, :String, default: "git,beginners"
 variable :FACEBOOK_PIXEL_ID, :String, default: "Optional"
 variable :SMARTY_STREETS_WEB_KEY, :String, default: "Optional"
 
+# New relic
+variable :NEW_RELIC_LICENSE_KEY, :String, default: "Optional"
 
 group :production do
   variable :SECRET_KEY_BASE, :String

Gemfile

@@ -89,7 +89,7 @@ gem "sdoc", "~> 1.0", group: :doc
 gem "serviceworker-rails", "~> 0.5"
 gem "share_meow_client", "~> 0.1"
 gem "sitemap_generator", "~> 6.0"
-gem "skylight", "~> 3.1"
+gem "skylight"
 gem "slack-notifier", "~> 2.3"
 gem "sprockets", "~> 3.7"
 gem "staccato", "~> 0.5"
@@ -117,7 +117,7 @@ group :development do
   gem "web-console", "~> 3.7"
 end
 
-group :development, :test do
+group :development, :lp, :test do
   gem "capybara", "~> 3.13"
   gem "derailed", "~> 0.1"
   gem "erb_lint", "~> 0.0", require: false
@@ -133,6 +133,7 @@ group :development, :test do
   gem "spring", "~> 2.0"
   gem "spring-commands-rspec", "~> 1.0"
   gem "vcr", "~> 4.0"
+  gem 'meta_request'
 end
 
 group :test do
@@ -157,3 +158,7 @@ group :test do
   gem "zonebie", "~> 0.6.1"
 end
 # rubocop:enable LineLength
+
+gem 'newrelic_rpm'
+gem 'prometheus_exporter'
+gem 'rack-mini-profiler', require: false

Gemfile.lock

@@ -137,6 +137,7 @@ GEM
       descendants_tracker (~> 0.0.4)
       ice_nine (~> 0.11.0)
       thread_safe (~> 0.3, >= 0.3.1)
+    base64 (0.1.1)
     bcrypt (3.1.12)
     benchmark-ips (2.7.2)
     better_errors (2.5.0)
@@ -592,6 +593,9 @@ GEM
     memoizable (0.4.2)
       thread_safe (~> 0.3, >= 0.3.1)
     memory_profiler (0.9.12)
+    meta_request (0.7.4)
+      rack-contrib (>= 1.1, < 3)
+      railties (>= 3.0.0, < 7.1)
     method_source (0.9.2)
     mime-types (3.2.2)
       mime-types-data (~> 3.2015)
@@ -612,6 +616,8 @@ GEM
     net-http-persistent (3.0.0)
       connection_pool (~> 2.2)
     netrc (0.11.0)
+    newrelic_rpm (9.6.0)
+      base64
     nio4r (2.3.1)
     nokogiri (1.10.1)
       mini_portile2 (~> 2.4.0)
@@ -651,6 +657,8 @@ GEM
       ast (~> 2.4.0)
     pg (1.1.4)
     powerpack (0.1.2)
+    prometheus_exporter (2.0.8)
+      webrick
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
@@ -675,8 +683,12 @@ GEM
     pusher-signature (0.1.8)
     raabro (1.1.6)
     rack (2.0.6)
+    rack-contrib (2.4.0)
+      rack (< 4)
     rack-host-redirect (1.3.0)
       rack
+    rack-mini-profiler (3.1.1)
+      rack (>= 1.2.0)
     rack-protection (2.0.4)
       rack
     rack-proxy (0.6.5)
@@ -932,6 +944,7 @@ GEM
     webpush (0.3.2)
       hkdf (~> 0.2)
       jwt
+    webrick (1.8.1)
     websocket-driver (0.6.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.3)
@@ -1012,14 +1025,17 @@ DEPENDENCIES
   libhoney (~> 1.11)
   liquid (~> 4.0)
   memory_profiler (~> 0.9)
+  meta_request
   nakayoshi_fork
+  newrelic_rpm
   nokogiri (~> 1.10)
   octokit (~> 4.13)
   omniauth (~> 1.9)
   omniauth-github (~> 1.3)
   omniauth-twitter (~> 1.4)
   parallel_tests (~> 2.27)
   pg (~> 1.1)
+  prometheus_exporter
   pry (~> 0.12)
   pry-byebug (~> 3.7)
   pry-rails (~> 0.3)
@@ -1029,6 +1045,7 @@ DEPENDENCIES
   pusher (~> 1.3)
   pusher-push-notifications (~> 1.0)
   rack-host-redirect (~> 1.3)
+  rack-mini-profiler
   rack-timeout (~> 0.5)
   rails (~> 5.1.6)
   rails-assets-airbrake-js-client (~> 1.5)!
@@ -1057,7 +1074,7 @@ DEPENDENCIES
   simplecov (~> 0.16)
   sinatra (~> 2.0)
   sitemap_generator (~> 6.0)
-  skylight (~> 3.1)
+  skylight
   slack-notifier (~> 2.3)
   spring (~> 2.0)
   spring-commands-rspec (~> 1.0)

Procfile.lp

@@ -0,0 +1,4 @@
+web: bin/rails s -p 3000 -e lp
+webpacker: ./bin/webpack-dev-server
+job: bin/rake jobs:work
+prometheus_exporter: bundle exec prometheus_exporter

app/views/stories/_main_stories_feed.html.erb

@@ -55,7 +55,9 @@
     <% if !user_signed_in? && i == 4 %>
       <%= render "stories/sign_in_invitation" %>
     <% end %>
-    <%= render "articles/single_story", story: story %>
+    <% cache story do %>
+      <%= render "articles/single_story", story: story %>
+    <% end %>
   <% end %>
 <% end %>
 <% if @stories.size > 1 %>

bin/startup

@@ -11,6 +11,13 @@ def system!(*args)
 end
 
 chdir APP_ROOT do
+  env = ENV.fetch('RAILS_ENV', 'development')
   puts "== STARTING UP =="
-  system! "foreman start -f Procfile.dev"
+
+  if env == 'lp'
+    system! "bundle exec rake assets:precompile"
+    system! "foreman start -f Procfile.lp"
+  else
+    system! "foreman start -f Procfile.dev"
+  end
 end

case-study.md

@@ -0,0 +1,19 @@
+# Оптимизация
+
+## Кэширование `_single_story.html.erb` в `_main_stories_feed.html.erb`
+
+Добавление кэширования по стори позволило ускорить загрузку главной страницы почти в 2 раза.
+
+### AB
+
+#### before
+
+Time per request: 212.047 ms
+
+https://gist.github.com/peresvetjke/22b0076f71bb49000aa3c3f082889d85
+
+#### after
+
+Time per request: 114.685 ms
+
+https://gist.github.com/peresvetjke/5b0a328f332dda0c43c7d8466f927bde

config/application.rb

@@ -53,5 +53,7 @@ class Application < Rails::Application
       end
       ReservedWords.all = [ReservedWords::BASE_WORDS + top_routes].flatten.compact.uniq
     end
+
+    config.skylight.environments << 'lp'
   end
 end

config/environments/lp.rb

@@ -0,0 +1,102 @@
+# rubocop:disable Metrics/BlockLength
+#
+def yarn_integrity_enabled?
+  ENV.fetch("YARN_INTEGRITY_ENABLED", "false") == "true"
+end
+
+Rails.application.configure do
+  # Verifies that versions and hashed value of the package contents in the project's package.json
+  config.webpacker.check_yarn_integrity = yarn_integrity_enabled?
+
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # In the development environment your application's code is reloaded on
+  # every request. This slows down response time but is perfect for development
+  # since you don't have to restart the web server when you make code changes.
+  config.cache_classes = true
+
+  # Do not eager load code on boot.
+  config.eager_load = true
+
+  # Show full error reports and disable caching.
+  config.consider_all_requests_local = true
+
+  # Enable/disable caching. By default caching is disabled.
+  if Rails.root.join("tmp/caching-dev.txt").exist?
+    config.action_controller.perform_caching = true
+
+    config.cache_store = :memory_store
+    config.public_file_server.headers = {
+      "Cache-Control" => "public, max-age=172800"
+    }
+  else
+    config.action_controller.perform_caching = false
+
+    config.cache_store = :null_store
+  end
+
+  # Don't care if the mailer can't send.
+  config.action_mailer.raise_delivery_errors = false
+
+  # Print deprecation notices to the Rails logger.
+  config.active_support.deprecation = :log
+
+  # Raise an error on page load if there are pending migrations.
+  config.active_record.migration_error = :page_load
+
+  # Debug mode disables concatenation and preprocessing of assets.
+  # This option may cause significant delays in view rendering with a large
+  # number of complex assets.
+  config.assets.debug = false
+
+  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
+  # yet still be able to expire them through the digest params.
+  config.assets.digest = false
+
+  # Supress logger output for asset requests.
+  config.assets.quiet = true
+
+  # Do not fallback to assets pipeline if a precompiled asset is missed.
+  config.assets.compile = true
+
+  # Adds additional error checking when serving assets at runtime.
+  # Checks for improperly declared sprockets dependencies.
+  # Raises helpful error messages.
+  config.assets.raise_runtime_errors = true
+
+  config.action_mailer.perform_caching = false
+
+  config.app_domain = "localhost:3000"
+
+  config.action_mailer.default_url_options = { host: "localhost:3000" }
+  config.action_mailer.delivery_method = :smtp
+  config.action_mailer.perform_deliveries = true
+  config.action_mailer.default_url_options = { host: config.app_domain }
+  config.action_mailer.smtp_settings = {
+    address: "smtp.gmail.com",
+    port: "587",
+    enable_starttls_auto: true,
+    user_name: '<%= ENV["DEVELOPMENT_EMAIL_USERNAME"] %>',
+    password: '<%= ENV["DEVELOPMENT_EMAIL_PASSWORD"] %>',
+    authentication: :plain,
+    domain: "localhost:3000"
+  }
+
+  config.action_mailer.preview_path = "#{Rails.root}/spec/mailers/previews"
+
+  # Raises error for missing translations
+  # config.action_view.raise_on_missing_translations = true
+
+  config.public_file_server.enabled = true
+
+  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
+
+  # Install the Timber.io logger
+  send_logs_to_timber = ENV["SEND_LOGS_TO_TIMBER"] || "false" # <---- set to false to stop sending dev logs to Timber.io
+  log_device = send_logs_to_timber == "true" ? Timber::LogDevices::HTTP.new(ENV["TIMBER"]) : STDOUT
+  logger = Timber::Logger.new(log_device)
+  logger.level = config.log_level
+  config.logger = ActiveSupport::TaggedLogging.new(logger)
+end
+
+# rubocop:enable Metrics/BlockLength

config/initializers/airbrake.rb

@@ -7,6 +7,7 @@
 #
 # Configuration details:
 # https://github.com/airbrake/airbrake-ruby#configuration
+
 Airbrake.configure do |c|
   # You must set both project_id & project_key. To find your project_id and
   # project_key navigate to your project's General Settings and copy the values
@@ -41,7 +42,7 @@
   # environments.
   # NOTE: This option *does not* work if you don't set the 'environment' option.
   # https://github.com/airbrake/airbrake-ruby#ignore_environments
-  c.ignore_environments = %w[test development]
+  c.ignore_environments = %w[test development lp]
 
   # A list of parameters that should be filtered out of what is sent to
   # Airbrake. By default, all "password" attributes will have their contents

config/initializers/carrierwave.rb

@@ -3,7 +3,7 @@
 require "carrierwave/storage/fog"
 
 CarrierWave.configure do |config|
-  if Rails.env.development? || Rails.env.test?
+  if %w[development test lp].include?(Rails.env)
     config.storage = :file
   else
     # config.fog_provider = 'fog-aws'

config/initializers/honeycomb.rb

@@ -3,7 +3,7 @@
 key = ApplicationConfig["HONEYCOMB_API_KEY"]
 dataset = "dev.to-#{Rails.env}"
 
-$libhoney = if Rails.env.development? || Rails.env.test?
+$libhoney = if %w[development test lp].include?(Rails.env)
               Libhoney::NullClient.new
             else
               Libhoney::Client.new(

config/initializers/prometheus.rb

@@ -0,0 +1,6 @@
+if Rails.env != "test"
+  require 'prometheus_exporter/middleware'
+
+  # This reports stats per request like HTTP status and timings
+  Rails.application.middleware.unshift PrometheusExporter::Middleware
+end

config/initializers/rack_mini_profiler.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+if %w[development lp].include?(Rails.env)
+  require "rack-mini-profiler"
+
+  # The initializer was required late, so initialize it manually.
+  Rack::MiniProfilerRails.initialize!(Rails.application)
+  Rack::MiniProfiler.config.authorization_mode = :allow_all if Rails.env.lp?
+end