Adds private ips method to Internet

README.md

@@ -53,7 +53,7 @@ Contents
 - [Contributing](#contributing)
 - [Contact](#contact)
 - [License](#license)
-  
+
 Installing
 ----------
 ```bash
@@ -279,8 +279,10 @@ Faker::Internet.domain_suffix #=> "info"
 
 Faker::Internet.ip_v4_address #=> "24.29.18.175"
 
-# Guaranteed not to be in 10.0.0.0/8, 127.0.0.0/8, 169.254.0.0/16,
-# 172.16.0.0/12, or 192.168.0.0/16
+# Private IP range according to RFC 1918 and 127.0.0.0/8 and 169.254.0.0/16.
+Faker::Internet.private_ip_v4_address #=> "10.0.0.1"
+
+# Guaranteed not to be in the ip range from the private_ip_v4_address method.
 Faker::Internet.public_ip_v4_address #=> "24.29.18.175"
 
 Faker::Internet.ip_v4_cidr #=> "24.29.18.175/21"

lib/faker/internet.rb

@@ -104,21 +104,36 @@ def ip_v4_address
         ary.sample].join('.')
       end
 
+      def private_ip_v4_address
+        is_private = private_net_checker
+        addr = nil
+        begin
+          addr = ip_v4_address
+        end while !is_private[addr]
+        addr
+      end
+
       def public_ip_v4_address
-        private_nets = [
+        is_private = private_net_checker
+        addr = nil
+        begin
+          addr = ip_v4_address
+        end while is_private[addr]
+        addr
+      end
+
+      def private_nets_regex
+        [
           /^10\./,
           /^127\./,
           /^169\.254\./,
           /^172\.(16|17|18|19|2\d|30|31)\./,
           /^192\.168\./
         ]
+      end
 
-        is_private = lambda {|addr| private_nets.any?{|net| net =~ addr}}
-        addr = nil
-        begin
-          addr = ip_v4_address
-        end while is_private[addr]
-        addr
+      def private_net_checker
+        lambda { |addr| private_nets_regex.any? { |net| net =~ addr } }
       end
 
       def ip_v4_cidr

test/test_faker_internet.rb

@@ -115,6 +115,21 @@ def test_ip_v4_address
     end
   end
 
+  def test_private_ip_v4_address
+    ten_dot = /^10\./
+    one_two_seven = /^127\./
+    one_six_nine = /^169\.254/
+    one_nine_two = /^192\.168\./
+    one_seven_two = /^172\.(16|17|18|19|20|21|22|23|24|25|26|27|28|29|30|31)\./
+
+    1000.times do
+      address = @tester.private_ip_v4_address
+      assert_match Regexp.new(
+        "(#{ten_dot})|(#{one_two_seven})|(#{one_six_nine})|(#{one_nine_two})|(#{one_seven_two})"
+      ), address
+    end
+  end
+
   def test_public_ip_v4_address
     ten_dot = /^10\./
     one_two_seven = /^127\./