Add new master_name param for sentinel. Fixes #531

lib/redis.rb

@@ -44,6 +44,7 @@ def self.current=(redis)
   # @option options [Boolean] :inherit_socket (false) Whether to use socket in forked process or not
   # @option options [Array] :sentinels List of sentinels to contact
   # @option options [Symbol] :role (:master) Role to fetch via Sentinel, either `:master` or `:slave`
+  # @option options [String] :master_name Master group name according to the `monitor` line in Sentinel config
   #
   # @return [Redis] a new client instance
   def initialize(options = {})

lib/redis/client.rb

@@ -509,7 +509,7 @@ def initialize(options)
 
           @sentinels = @options.delete(:sentinels).dup
           @role = @options.fetch(:role, "master").to_s
-          @master = @options[:host]
+          @master = @options[:master_name] || @options[:host]
         end
 
         def check(client)

test/sentinel_test.rb

@@ -196,6 +196,32 @@ def test_sentinel_role_mismatch
     assert_match(/Instance role mismatch/, ex.message)
   end
 
+  def test_sentinel_master_name
+    sentinels = [{:host => "127.0.0.1", :port => 26381}]
+
+    commands = {
+      :s1 => [],
+    }
+
+    handler = lambda do |id|
+      {
+        :sentinel => lambda do |command, *args|
+          commands[id] << [command, *args]
+          ["127.0.0.1", "6381"]
+        end
+      }
+    end
+
+    RedisMock.start(handler.call(:s1)) do |s1_port|
+      sentinels[0][:port] = s1_port
+      redis = Redis.new(:url => "redis://master1", :sentinels => sentinels, :role => :master, :master_name => :new_master)
+
+      assert redis.ping
+    end
+
+    assert_equal commands[:s1], [%w[get-master-addr-by-name new_master]]
+  end
+
   def test_sentinel_retries
     sentinels = [{:host => "127.0.0.1", :port => 26381},
                  {:host => "127.0.0.1", :port => 26382}]