Missing host argument of connection block?

[gdsotirov]

Should not the connection block of the remote-exec provisioner have the required host argument? While I was playing with the GCP example, Terraform 0.13 stopped me with the following error:

Error: Missing required argument

  on main.tf line 50, in resource "google_compute_instance" "tfansible":
  50: 		connection {

The argument "host" is required, but no definition was found.

P.S. I'm using SSH agent, so I removed private key definition.