1. In the console, go to Ocean > Cloud clusters.
2. Select the cluster you want to configure.
3. Go to Virtual node groups and select Create VNG.
4. If you want to create a launch specification with custom attributes, expand Node selection and add your attribute keys and values.
   • Example:
     • Key: stack
     • Value: dev

 

5. Add the same custom attribute to your instance’s startup script.
   • For example, include this line in your user data:

     echo ECS_INSTANCE_ATTRIBUTES='{"stack":"dev"}' >> /etc/ecs/ecs.config
     

6. Add a constraint to your task definition or service so tasks run only on instances that match your attribute.
   • Example:

     memberOf(attribute:stack==dev)
     

When a new instance launches, it’s created from the virtual node group that matches the attribute.

Instances are launched only from the virtual node group that matches your chosen attributes, allowing you to control scheduling and placement based on your configuration.