* adds `bastion_*` fields to `connection` which add configuration for a
bastion host
* if `bastion_host` is set, connect to that host first, then jump
through it to make the SSH connection to `host`
* enables SSH Agent forwarding by default
This changes SSH Agent utilization from opt-in to opt-out, bringing
Terraform in line with the behavior of Packer and the `ssh` command
itself.
But skip SSH agent connections if the SSH_AUTH_SOCK env var doesn't exist,
whcih means there's no agent to connect to.
The commit is pretty complete and has a tested/working provisioner for
both SSH and WinRM. There are a few tests, but we maybe need another
few to have better coverage. Docs are also included…
The Terraform configuration syntax defines what arrays are.
Use the word array consistently throughout the documentation
instead of list.
The corresponding JSON datatype is called array as well, and
since the Terraform configuration syntax is interoperable with
JSON it makes sense to use the term array to describe them.
Paul Hinze