Blue/green deployment for ACS with Docker Swarm?

Hi.

I’m new with Azure Container Service and want to setup Docker Swarm on the Azure’s ACS using a template from the azure-quickstart-templates.

Idea is - to have dedicated Resource Group per each environment for each application, i.e.:

Application 1: app-1-resgroup-DEV
Application 1: app-1-resgroup-QA
etc

and:

Application 2: app-2-resgroup-DEV
Application 2: app-2-resgroup-DEV
etc

And a question here is - what about “Deployment slots” analog here?

Setup two Swarm clusters in same Resource Group and add dedicated Load Balancer to use it as “STAGE => PROD selector”? Setup two separate groups? Where put LB then?

What is a correct approach? Or my solution wrong at all and this must be done in some other way?

Thanks.