Docker: Deploy Workers to Group Other than "default"

Yes, if you follow the install instructions here:

Docker Deployment | Cribl Docs

You can use the following docker-compose.yml to stand up a Cribl Stream distributed deployment of a Leader and one or more Workers:

Inside of the docker-compse.yml you will see the environmental variable for
CRIBL_DIST_MASTER_URL=tcp://servername:4200

You will just want to edit the environmental variable to include the non default group name after the port.
CRIBL_DIST_MASTER_URL=tcp://servername:4200?group=foo

Reference doc for the different environment variable that can be added:

Environment Variables | Cribl Docs

Environment variables available for configuring Cribl Stream