implement the cache purger

Gemfile

@@ -29,7 +29,7 @@ gem 'rest-client'
 gem 'geoip'
 gem 'io-extra', require: 'io/extra'
 gem 'rye'
-gem 'timecop'
+gem 'dnsruby'
 
 platform :mri, :rbx do
   gem 'magic' # sudo apt-get install file, For OSX: brew install libmagic
@@ -76,6 +76,7 @@ group :test do
   gem 'rack_session_access',   require: nil
   gem 'webmock',               require: nil
   gem 'stripe-ruby-mock',      '~> 2.0.1', require: 'stripe_mock'
+  gem 'timecop'
 
   platform :mri, :rbx do
     gem 'simplecov',        require: nil

Gemfile.lock

@@ -49,6 +49,7 @@ GEM
       rack (>= 1.1.0)
       uuidtools (~> 2.1.1)
     debugger-linecache (1.2.0)
+    dnsruby (1.58.0)
     docile (1.1.3)
     domain_name (0.5.23)
       unf (>= 0.0.5, < 1.0.0)
@@ -261,6 +262,7 @@ DEPENDENCIES
   capybara_minitest_spec
   cocaine
   dav4rack
+  dnsruby
   erubis
   fabrication
   faker

environment.rb

@@ -75,18 +75,6 @@ if ENV['RACK_ENV'] == 'development'
 end
 # :nocov:
 
-# :nocov:
-if $config['pubsub_url']
-  $pubsub_pool = ConnectionPool.new(size: 10, timeout: 5) {
-    Redis.new url: $config['pubsub_url']
-  }
-end
-
-if $config['pubsub_url'].nil? && ENV['RACK_ENV'] == 'production'
-  raise 'pubsub_url is missing from config'
-end
-# :nocov:
-
 Sequel.datetime_class = Time
 Sequel.extension :core_extensions
 Sequel.extension :migration

tests/workers/purge_cache_worker_tests.rb

@@ -0,0 +1,47 @@
+require_relative '../environment.rb'
+
+describe PurgeCacheWorker do
+  before do
+    @test_ips = ['10.0.0.1', '10.0.0.2']
+  end
+
+  it 'throws exception without 200 or 404 http status' do
+    @test_ips.each do |ip|
+      stub_request(:get, "https://#{ip}/:cache/purgetest.jpg").
+        with(headers: {'Host' => 'kyledrake.neocities.org'})
+        .to_return(status: 503)
+    end
+
+    worker = PurgeCacheWorker.new
+
+    proc {
+      worker.perform 'kyledrake', 'test.jpg'
+    }.must_raise RestClient::ServiceUnavailable
+  end
+
+  it 'handles 404 without exception' do
+    @test_ips.each do |ip|
+      stub_request(:get, "https://#{ip}/:cache/purgetest.jpg").
+        with(headers: {'Host' => 'kyledrake.neocities.org'})
+        .to_return(status: 404)
+    end
+
+    worker = PurgeCacheWorker.new
+    worker.perform 'kyledrake', 'test.jpg'
+  end
+
+  it 'sends a purge to each dns ip' do
+    @test_ips.each do |ip|
+      stub_request(:get, "https://#{ip}/:cache/purgetest.jpg").
+        with(headers: {'Host' => 'kyledrake.neocities.org'})
+        .to_return(status: 200)
+    end
+
+    worker = PurgeCacheWorker.new
+    worker.perform 'kyledrake', 'test.jpg'
+
+    @test_ips.each do |ip|
+      assert_requested :get, "https://#{ip}/:cache/purgetest.jpg"
+    end
+  end
+end

workers/purge_cache_worker.rb

@@ -2,21 +2,22 @@ class PurgeCacheWorker
   include Sidekiq::Worker
   sidekiq_options queue: :purgecache, retry: 10, backtrace: true
 
+  def perform(subdomain, path)
+    res = Dnsruby::Resolver.new
 
-  def perform(payload)
-    # :nocov:
-    attempt = 0
-    begin
-      attempt += 1
-      $pubsub_pool.with do |redis|
-        redis.publish 'purgecache', payload.to_json
-      end
-    rescue Redis::BaseConnectionError => error
-      raise if attempt > 3
-      puts "pubsub error: #{error}, retrying in 1s"
-      sleep 1
-      retry
+    if ENV['RACK_ENV'] == 'test'
+      proxy_ips = ['10.0.0.1', '10.0.0.2']
+    else
+      proxy_ips = res.query($config['cache_purge_ips_uri']).answer.collect {|a| a.address.to_s}
+    end
+
+    proxy_ips.each do |proxy_ip|
+      url = "http://#{proxy_ip}/:cache/purge#{path}"
+
+      begin
+        RestClient.get(url, host: "#{subdomain}.neocities.org")
+      rescue RestClient::ResourceNotFound
+      end
     end
-    # :nocov:
   end
 end