add container_start_args to pass options to the start command (#821)

lib/ood_core/batch_connect/templates/vnc_container.rb

@@ -70,6 +70,8 @@ class VNC_Container < Template
         #   empty string.
         # @option context [#to_s] :container_command ("singularity") the 
         #   singularity or apptainer execution command
+        # @option context [#to_a] :container_start_args ([]) Additional
+        #   arguements you wish to pass to the container start command.
         # @param instance_name (uuid) a name for the instance
         # @see Template
 
@@ -99,8 +101,8 @@ module load #{container_module}
               export INSTANCE_NAME="#{@instance_name}"
               export instance_name="#{@instance_name}"
               echo "Starting instance..."
-              #{container_command} instance start #{container_path} #{@instance_name}
-              
+              #{container_command} instance start #{container_start_args} #{container_path} #{@instance_name}
+
               # Setup one-time use passwords and initialize the VNC password
               function change_passwd () {
                 echo "Setting VNC password..."
@@ -219,6 +221,10 @@ def container_command
             context.fetch(:container_command, "singularity").to_s
           end
 
+          def container_start_args
+            context.fetch(:container_start_args, []).to_a.join(' ')
+          end
+
           # Arguments sent to `vncserver` command
           def vnc_args
             context.fetch(:vnc_args) do