support baremetal deployment (i.e. no infra automation)

[snowch]

@erdincka - does this look like it could work?

baremetal/myvars.tfvars

...
workers_private_ip = [ 1.2.3.4 ]
workers_private_dns = [  a.b.c ]
worker_count = [ 2 ]

baremetal/variables.tf

variable workers_private_ip { default = [] }
variable workers_private_dns { default = [ ] }
variable worker_count { default = [] }
...
output "workers_private_ip" {
  value = vars.workers_private_ip
}
output "workers_private_dns" {
  value = vars.workers_private_dns
}
output "worker_count" {
  value = vars.worker_count
}

We should just need these files and a config.json file?

[erdincka]

@snowch, I tried to document adding a new target in the ./CONTRIBUTING.md file. Also might be helpful to check ./server/mac folder. That uses terraform to run a script and generate the required output. Similar to what you have here, but few more options are needed, such as gateway_public_dns, (gateway|controller|worker)_prv_ips etc.

[erdincka]

The comment above is not valid anymore :)
This should work with "dc" (on-prem) deployment module.