Add LDAP_USERNAME and LDAP_PASSWORD user environment variables for QA

qa/qa/page/main/login.rb

@@ -53,8 +53,8 @@ module QA
             click_link 'LDAP'
-            fill_in :username, with: Runtime::User.name
-            fill_in :password, with: Runtime::User.password
+            fill_in :username, with: Runtime::User.ldap_username
+            fill_in :password, with: Runtime::User.ldap_password
             click_button 'Sign in'
           end
         end

qa/qa/runtime/env.rb

@@ -35,6 +35,14 @@ module QA
         ENV['GITLAB_PASSWORD']
       end
+      def ldap_username
+        ENV['GITLAB_LDAP_USERNAME']
+      end
+
+      def ldap_password
+        ENV['GITLAB_LDAP_PASSWORD']
+      end
+
       def sandbox_name
         ENV['GITLAB_SANDBOX_NAME']
       end

qa/qa/runtime/user.rb

@@ -18,6 +18,14 @@ module QA
       def ldap_user?
         Runtime::Env.user_type == 'ldap'
       end
+
+      def ldap_username
+        Runtime::Env.ldap_username || name
+      end
+
+      def ldap_password
+        Runtime::Env.ldap_password || password
+      end
     end
   end
 end