Different deployment environments

Curious how others are managing their rancher deployments to different environments. We have a 3 stage environment, lab, stage, production and the deployments should follow that natural path.

So i have my rancher configs living in a repo /stackname/docker-compose.yml + rancher-compose.yml and i can deploy easily using rancher up.

I can set different environment variables in the config files like $variable but wondering how others are doing it at the .yml level for different envs.

Like if env=lab then image: org/app:latest else if env=stage then image:org/app:1.01

Maybe something clever with the host “Require container level”?

Thanks in advance!