cache full pages for logged-out visitors without tag filters

Gemfile

@@ -1,34 +1,38 @@
 source "https://rubygems.org"
 
-gem "json"
 gem "rails", "~> 5.1"
 
-gem "unicorn"
-
 gem "mysql2", "~> 0.3.20"
 
 # uncomment to use PostgreSQL
 # gem "pg"
 
+# rails
 gem 'scenic'
 gem 'scenic-mysql'
+gem "activerecord-typedstore"
 
-gem "uglifier", ">= 1.3.0"
-gem "jquery-rails", "~> 4.3"
+# js
 gem "dynamic_form"
+gem "jquery-rails", "~> 4.3"
+gem "json"
+gem "uglifier", ">= 1.3.0"
 
+# deployment
+gem "actionpack-page_caching"
 gem "exception_notification"
+gem "unicorn"
 
+# security
 gem "bcrypt", "~> 3.1.2"
 gem "rotp"
 gem "rqrcode"
 
+# parsing
 gem "nokogiri", ">= 1.7.2"
 gem "htmlentities"
 gem "commonmarker", "~> 0.14"
 
-gem "activerecord-typedstore"
-
 # for twitter-posting bot
 gem "oauth"
 

Gemfile.lock

@@ -18,6 +18,8 @@ GEM
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionpack-page_caching (1.1.0)
+      actionpack (>= 4.0.0, < 6)
     actionview (5.1.5)
       activesupport (= 5.1.5)
       builder (~> 3.1)
@@ -194,6 +196,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  actionpack-page_caching
   activerecord-typedstore
   bcrypt (~> 3.1.2)
   bullet

app/controllers/application_controller.rb

@@ -5,8 +5,11 @@ class ApplicationController < ActionController::Base
 
   TRAFFIC_DECREMENTER = 0.50
 
+  # match this in your nginx config for bypassing the file cache
   TAG_FILTER_COOKIE = :tag_filters
 
+  CACHE_PAGE = proc { @user.blank? && cookies[TAG_FILTER_COOKIE].blank? }
+
   def authenticate_user
     # eagerly evaluate, in case this triggers an IpSpoofAttackError
     request.remote_ip

app/controllers/comments_controller.rb

@@ -1,6 +1,8 @@
 class CommentsController < ApplicationController
   COMMENTS_PER_PAGE = 20
 
+  caches_page :index, :threads, if: CACHE_PAGE
+
   # for rss feeds, load the user's tag filters if a token is passed
   before_action :find_user_from_rss_token, :only => [:index]
   before_action :require_logged_in_user_or_400,

app/controllers/home_controller.rb

@@ -1,4 +1,6 @@
 class HomeController < ApplicationController
+  caches_page :about, :chat, :index, :newest, :newest_by_user, :recent, :top, if: CACHE_PAGE
+
   # for rss feeds, load the user's tag filters if a token is passed
   before_action :find_user_from_rss_token, :only => [:index, :newest, :saved]
   before_action { @page = page }

app/controllers/stories_controller.rb

@@ -1,4 +1,6 @@
 class StoriesController < ApplicationController
+  caches_page :show, if: CACHE_PAGE
+
   before_action :require_logged_in_user_or_400,
                 :only => [:upvote, :downvote, :unvote, :hide, :unhide, :preview, :save, :unsave]
   before_action :require_logged_in_user,

config/environments/production.rb

@@ -75,6 +75,8 @@
 
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
+
+  config.action_controller.page_cache_directory = "#{Rails.root}/public/cache"
 end
 
 %w{render_template render_partial render_collection}.each do |event|

config/initializers/session_store.rb

@@ -1,5 +1,6 @@
 # Be sure to restart your server when you modify this file.
 
+# match this in your nginx config for bypassing the file cache
 Lobsters::Application.config.session_store :cookie_store,
                                            key: 'lobster_trap',
                                            expire_after: 1.month

script/expire_page_cache

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+find /srv/lobste.rs/http/public/cache/ -type f -not -mmin 2 -not -name ".gitkeep" -delete
+find /srv/lobste.rs/http/public/cache/ -type d -empty -delete