Update caching

Gemfile

@@ -55,7 +55,13 @@ gem 'friendly_id', '~> 5.0.3'
 
 gem 'rack-timeout'
 
-group :production, :staging do
+# Caching
+gem 'rack-cache'
+gem 'dalli'
+gem 'kgio'
+gem 'memcachier'
+
+group :production do
   # Heroku recommended
   gem 'rails_12factor'
 end

Gemfile.lock

@@ -71,6 +71,7 @@ GEM
       simplecov (>= 0.7)
       term-ansicolor
       thor
+    dalli (2.7.2)
     database_cleaner (1.3.0)
     debug_inspector (0.0.2)
     devise (3.4.1)
@@ -124,6 +125,7 @@ GEM
       rb-kqueue (>= 0.2)
     mail (2.6.3)
       mime-types (>= 1.16, < 3)
+    memcachier (0.0.2)
     mime-types (2.4.3)
     mini_portile (0.6.1)
     minitest (5.4.3)
@@ -153,6 +155,8 @@ GEM
     quiet_assets (1.0.3)
       railties (>= 3.1, < 5.0)
     rack (1.5.2)
+    rack-cache (1.2)
+      rack (>= 0.4)
     rack-cors (0.2.9)
     rack-test (0.6.2)
       rack (>= 1.0)
@@ -281,6 +285,7 @@ DEPENDENCIES
   capybara
   coffee-rails (~> 4.1.0)
   coveralls
+  dalli
   database_cleaner (>= 1.0.0.RC1)
   devise (~> 3.4)
   enumerize
@@ -292,13 +297,16 @@ DEPENDENCIES
   haml-rails (~> 0.5.3)
   jquery-rails
   kaminari
+  kgio
   listen (~> 1.0)
+  memcachier
   pg
   pg_search
   poltergeist
   protected_attributes
   pundit
   quiet_assets (>= 1.0.2)
+  rack-cache
   rack-cors
   rack-timeout
   rails (~> 4.1.1)

app/controllers/api/v1/locations_controller.rb

@@ -6,6 +6,8 @@ class LocationsController < ApplicationController
       include CustomErrors
       include Cacheable
 
+      after_action :set_cache_control, only: [:index, :show]
+
       def index
         locations = Location.includes(:organization, :address, :phones).
                     page(params[:page]).per(params[:per_page]).
@@ -21,8 +23,7 @@ def show
           services: [:categories, :contacts, :phones, :regular_schedules,
                      :holiday_schedules]
           ).find(params[:id])
-        render json: location, status: 200
-        expires_in cache_time, public: true
+        render json: location, status: 200 if stale?(location, public: true)
       end
 
       def update

app/controllers/api/v1/search_controller.rb

@@ -5,13 +5,16 @@ class SearchController < ApplicationController
       include CustomErrors
       include Cacheable
 
+      after_action :set_cache_control, only: :index
+
       def index
         locations = Location.search(params).page(params[:page]).
                     per(params[:per_page])
 
-        render json: locations.preload(tables), each_serializer: LocationsSerializer, status: 200
-        generate_pagination_headers(locations)
-        expires_in cache_time, public: true
+        if stale?(etag: cache_key(locations), public: true)
+          generate_pagination_headers(locations)
+          render json: locations.preload(tables), each_serializer: LocationsSerializer, status: 200
+        end
       end
 
       def nearby
@@ -26,17 +29,19 @@ def nearby
       private
 
       def tables
-        if params[:org_name].present? && params[:location].present?
-          [:address, :phones]
-        else
-          [:organization, :address, :phones]
-        end
+        [:organization, :address, :phones]
       end
 
       def locations_near(location)
         location.nearbys(params[:radius]).status('active').
           page(params[:page]).per(params[:per_page]).includes(:address)
       end
+
+      def cache_key(scope)
+        Digest::MD5.hexdigest(
+          "#{scope.to_sql}-#{scope.maximum(:updated_at)}-#{scope.total_count}"
+        )
+      end
     end
   end
 end

app/controllers/concerns/cacheable.rb

@@ -2,4 +2,8 @@ module Cacheable
   def cache_time
     ENV['EXPIRES_IN'].to_i.minutes
   end
+
+  def set_cache_control
+    expires_in cache_time, public: true
+  end
 end

config/application.example.yml

@@ -115,13 +115,13 @@
 #
 #############
 # This setting defines how long, in minutes, API responses will be cached in
-# a web client, such as Ohana Web Search:
-# https://github.com/codeforamerica/ohana-web-search
-# For example, if you set EXPIRES_IN to '5', when you do a search or
-# visit a specific location in Ohana Web Search, the app won't make that same
-# API request until 5 minutes have passed since the request was first made.
-# This greatly improves the performance of Ohana Web Search, and also reduces
-# the load on the API.
+# Rack::Cache. During that time interval, any API requests for that same
+# query (after the initial request) will be served by Rack::Cache instead
+# of the app, thereby reducing the load on the API and serving responses
+# quickly.
+# Read more about HTTP Caching:
+# http://railscasts.com/episodes/321-http-caching?view=asciicast
+# https://devcenter.heroku.com/articles/http-caching-ruby-rails
 
 ######################################
 #
@@ -189,7 +189,7 @@ production:
   DEV_SUBDOMAIN:
   DEFAULT_PER_PAGE: '30'
   MAX_PER_PAGE: '50'
-  EXPIRES_IN: '5'
+  EXPIRES_IN: '1'
   TLD_LENGTH: '2'
   ENABLE_HTTPS: yes
 

config/environments/development.rb

@@ -11,7 +11,18 @@
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
-  config.action_controller.perform_caching = false
+
+  # Uncomment the section below to test HTTP caching in development.
+  # You'll need to install memcached if you don't already have it:
+  # brew install memcached
+  #
+  # config.action_controller.perform_caching = true
+  # config.cache_store = :dalli_store
+  # client = Dalli::Client.new
+  # config.action_dispatch.rack_cache = {
+  #   metastore: client,
+  #   entitystore: client
+  # }
 
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false

config/environments/production.rb

@@ -15,16 +15,7 @@
   config.eager_load = true
 
   # Full error reports are disabled and caching is turned on.
-  config.consider_all_requests_local       = false
-  config.action_controller.perform_caching = true
-
-  # Enable Rack::Cache to put a simple HTTP cache in front of your application
-  # Add `rack-cache` to your Gemfile before enabling this.
-  # For large-scale production use, consider using a caching reverse proxy like nginx, varnish or squid.
-  # config.action_dispatch.rack_cache = true
-
-  # Disable Rails's static asset server (Apache or nginx will already do this).
-  config.serve_static_assets = false
+  config.consider_all_requests_local = false
 
   # Compress JavaScripts and CSS.
   config.assets.js_compressor  = :uglifier
@@ -33,9 +24,6 @@
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # Generate digests for assets URLs.
-  config.assets.digest = true
-
   # `config.assets.version` and `config.assets.precompile` have moved to config/initializers/assets.rb
 
   # Specifies the header that your server uses for sending files.
@@ -54,8 +42,37 @@
   # Use a different logger for distributed setups.
   # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
 
-  # Use a different cache store in production.
-  # config.cache_store = :mem_cache_store
+  # --------------------------------------------------------------------------
+  # CACHING SETUP FOR RACK:CACHE AND MEMCACHIER ON HEROKU
+  # https://devcenter.heroku.com/articles/rack-cache-memcached-rails31
+  # ------------------------------------------------------------------
+
+  config.serve_static_assets = true
+
+  # Generate digests for assets URLs.
+  config.assets.digest = true
+
+  config.action_controller.perform_caching = true
+
+  config.cache_store = :dalli_store
+  client = Dalli::Client.new((ENV['MEMCACHIER_SERVERS'] || '').split(','),
+                             username: ENV['MEMCACHIER_USERNAME'],
+                             password: ENV['MEMCACHIER_PASSWORD'],
+                             failover: true,
+                             socket_timeout: 1.5,
+                             socket_failure_delay: 0.2,
+                             value_max_bytes: 10_485_760)
+
+  # Enable Rack::Cache to put a simple HTTP cache in front of your application.
+  # Add `rack-cache` to your Gemfile before enabling this.
+  # For large-scale production use, consider using a caching reverse proxy like
+  # nginx, varnish or squid.
+  config.action_dispatch.rack_cache = {
+    metastore:   client,
+    entitystore: client
+  }
+  config.static_cache_control = 'public, max-age=2592000'
+  # --------------------------------------------------------------------------
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
   # config.action_controller.asset_host = "http://assets.example.com"

script/setup_heroku

@@ -30,6 +30,9 @@ then
   echo "Installing Mandrill by MailChimp"
   heroku addons:add mandrill --app $herokuApp
 
+  echo "Installing Memcachier"
+  heroku addons:add memcachier --app $herokuApp
+
   echo "All done setting up env vars and add-ons."
   echo "Pushing code to Heroku now. This will take a few minutes..."
   git push heroku master
@@ -38,4 +41,4 @@ then
 else
   echo "Please add your Heroku app name to the end of the command."
   echo "Usage: setup_heroku your_app_name"
-fi
+fi