Fix misbehavior around connection to slave node in pool

The idea behind this fix is following:
if u connect to slave node its should notify u where is you master, then
u reconnect to master and perform any actions in front this server

lib/fog/xenserver/compute.rb

@@ -123,6 +123,11 @@ module Fog
           @defaults    = options[:xenserver_defaults] || {}
           @timeout     = options[:xenserver_timeout] || 30
           @connection  = Fog::XenServer::Connection.new(@host, @timeout)
+	  host_master  = @connection.find_pool_master(@username, @password)
+	  if host_master!= @host
+		@host = host_master;
+	        @connection  = Fog::XenServer::Connection.new(@host, @timeout)
+	  end
           @connection.authenticate(@username, @password)
         end
 

lib/fog/xenserver/core.rb

@@ -22,6 +22,19 @@ module Fog
         @factory.timeout = timeout
       end
 
+      def find_pool_master( username, password )
+        response = @factory.call('session.login_with_password', username.to_s, password.to_s)
+        raise Fog::XenServer::InvalidLogin.new unless response["Status"] =~ /Success/
+        @credentials = response["Value"]
+	response = @factory.call('host.get_all_records', @credentials)
+	if response['Status'] == "Failure" 
+		if response['ErrorDescription'][0] == "HOST_IS_SLAVE" 
+			response['ErrorDescription'][1]
+		end
+	end
+      end
+
+
       def authenticate( username, password )
         response = @factory.call('session.login_with_password', username.to_s, password.to_s)
         raise Fog::XenServer::InvalidLogin.new unless response["Status"] =~ /Success/