Support checking whether a domain points at a GitHub Pages IP address

README.md

@@ -52,12 +52,13 @@
  :apex_domain?=>true,
  :should_be_a_record?=>true,
  :pointed_to_github_user_domain?=>false,
+ :pointed_to_github_pages_ip?=>false,
  :pages_domain?=>false,
  :valid?=>true
 }
-> require 'json'
+> require "json"
 > check.to_json
-=> "{\"cloudflare_ip?\":false,\"old_ip_address?\":false,\"a_record?\":true,\"cname_record?\":false,\"valid_domain?\":true,\"apex_domain?\":true,\"should_be_a_record?\":true,\"pointed_to_github_user_domain?\":false,\"pages_domain?\":false,\"valid?\":true}"
+=> "{\"cloudflare_ip?\":false,\"old_ip_address?\":false,\"a_record?\":true,\"cname_record?\":false,\"valid_domain?\":true,\"apex_domain?\":true,\"should_be_a_record?\":true,\"pointed_to_github_user_domain?\":false,\"pointed_to_github_pages_ip?\":false,\"pages_domain?\":false,\"valid?\":true}"
 ```
 
 ### Getting the reason a domain is invalid

github-pages-health-check.gemspec

@@ -1,4 +1,4 @@
-require File.expand_path('../lib/github-pages-health-check/version', __FILE__)
+require File.expand_path("../lib/github-pages-health-check/version", __FILE__)
 
 Gem::Specification.new do |s|
   s.required_ruby_version = ">= 1.9.3"

lib/github-pages-health-check.rb

@@ -1,16 +1,16 @@
-require 'net/dns'
-require 'net/dns/resolver'
-require 'ipaddr'
-require 'public_suffix'
-require 'singleton'
-require 'net/http'
-require_relative 'github-pages-health-check/version'
-require_relative 'github-pages-health-check/cloudflare'
-require_relative 'github-pages-health-check/error'
-require_relative 'github-pages-health-check/errors/deprecated_ip'
-require_relative 'github-pages-health-check/errors/invalid_a_record'
-require_relative 'github-pages-health-check/errors/invalid_cname'
-require_relative 'github-pages-health-check/errors/not_served_by_pages'
+require "net/dns"
+require "net/dns/resolver"
+require "ipaddr"
+require "public_suffix"
+require "singleton"
+require "net/http"
+require_relative "github-pages-health-check/version"
+require_relative "github-pages-health-check/cloudflare"
+require_relative "github-pages-health-check/error"
+require_relative "github-pages-health-check/errors/deprecated_ip"
+require_relative "github-pages-health-check/errors/invalid_a_record"
+require_relative "github-pages-health-check/errors/invalid_cname"
+require_relative "github-pages-health-check/errors/not_served_by_pages"
 
 class GitHubPages
   class HealthCheck
@@ -23,6 +23,11 @@ class HealthCheck
       199.27.73.133
     ]
 
+    CURRENT_IP_ADDRESSES = %w[
+      192.30.252.153
+      192.30.252.154
+    ]
+
     def initialize(domain)
       @domain = domain
     end
@@ -76,6 +81,11 @@ def pointed_to_github_user_domain?
       dns.first.class == Net::DNS::RR::CNAME && pages_domain?(dns.first.cname.to_s)
     end
 
+    # Is the domain's first response an A record to a valid GitHub Pages IP?
+    def pointed_to_github_pages_ip?
+      dns.first.class == Net::DNS::RR::A && CURRENT_IP_ADDRESSES.include?(dns.first.value)
+    end
+
     # Is the given cname a pages domain?
     #
     # domain - the domain to check, generaly the target of a cname
@@ -98,6 +108,7 @@ def to_hash
         :apex_domain?                   => apex_domain?,
         :should_be_a_record?            => should_be_a_record?,
         :pointed_to_github_user_domain? => pointed_to_github_user_domain?,
+        :pointed_to_github_pages_ip?    => pointed_to_github_pages_ip?,
         :pages_domain?                  => pages_domain?,
         :served_by_pages?               => served_by_pages?,
         :valid?                         => valid?,

lib/github-pages-health-check/version.rb

@@ -1,5 +1,5 @@
 class GitHubPages
   class HealthCheck
-    VERSION = '0.2.2'
+    VERSION = "0.2.2"
   end
 end

spec/github_pages_health_check_cloudflare_spec.rb

@@ -1,7 +1,7 @@
-require 'spec_helper'
-require 'json'
-require 'tempfile'
-require 'ipaddr'
+require "spec_helper"
+require "json"
+require "tempfile"
+require "ipaddr"
 
 describe(GitHubPages::HealthCheck::CloudFlare) do
 
@@ -11,7 +11,7 @@
 
   context "default" do
     let(:instance) { GitHubPages::HealthCheck::CloudFlare.instance }
-    
+
     it "loads the default config" do
       path = File.expand_path(instance.path)
       expected = File.expand_path("../config/cloudflare-ips.txt", File.dirname(__FILE__))

spec/github_pages_health_check_spec.rb

@@ -1,5 +1,5 @@
-require 'spec_helper'
-require 'json'
+require "spec_helper"
+require "json"
 
 describe(GitHubPages::HealthCheck) do
   let(:health_check) { GitHubPages::HealthCheck.new("foo.github.io") }
@@ -89,6 +89,21 @@ def cname_packet(domain)
     end
   end
 
+  it "can determine when an apex domain is pointed at a GitHub Pages IP address" do
+    allow(health_check).to receive(:domain) { "getbootstrap.com" }
+    expect(health_check.pointed_to_github_pages_ip?).to be(true)
+  end
+
+  it "can determine when an apex domain is not pointed at a GitHub Pages IP address" do
+    allow(health_check).to receive(:domain) { "example.com" }
+    expect(health_check.pointed_to_github_pages_ip?).to be(false)
+  end
+
+  it "can determine that a subdomain with a CNAME record is not pointed at a GitHub Pages IP address" do
+    allow(health_check).to receive(:domain) { "pages.github.com" }
+    expect(health_check.pointed_to_github_pages_ip?).to be(false)
+  end
+
   it "retrieves a site's dns record" do
     allow(health_check).to receive(:domain) { "pages.github.com" }
     expect(health_check.dns.first.class).to eql(Net::DNS::RR::CNAME)
@@ -123,7 +138,7 @@ def cname_packet(domain)
 
   it "returns valid json" do
     data = JSON.parse GitHubPages::HealthCheck.new("benbalter.com").to_json
-    expect(data.length).to eql(12)
+    expect(data.length).to eql(13)
     data.each { |key, value| expect([true,false,nil].include?(value)).to eql(true) }
   end
 

spec/spec_helper.rb

@@ -9,5 +9,5 @@
   # order dependency and want to debug it, you can fix the order by providing
   # the seed, which is printed after each run.
   #     --seed 1234
-  config.order = 'random'
+  config.order = "random"
 end