We haven't had this particular usecase recently (i.e. having a ssh-provided machine in a model and deploying a bundle with --map-machines=existing on top).
The workaround at the time was to add-machine (juju add-machine --series xenial zone=$zone --constraints tags=os-cs-vnf) all the nodes first, then deploy the bundle with --map-machines=existing.
We haven't had this particular usecase recently (i.e. having a ssh-provided machine in a model and deploying a bundle with --map-machines= existing on top).
The workaround at the time was to add-machine (juju add-machine --series xenial zone=$zone --constraints tags=os-cs-vnf) all the nodes first, then deploy the bundle with --map-machines= existing.