SSH connect GCP - ssh

Question

I at the deadlock. I try to connect to the created VM over SSH, but nothing comes out. Added the following entries to the terraform
provisioner "remote-exec" {
inline = [
"/bin/echo -e \"${element(random_string.password.*.result, count.index)}\n${element(random_string.password.*.result, count.index)}\" | /usr/bin/passwd root"
]
connection {
type = "ssh"
user = "root"
private_key = file(var.privat_google_key)
agent = false
timeout = "5m"
host = google_compute_instance.webserver[count.index].network_interface[0].access_config[0].nat_ip
}
}
...
resource "google_compute_project_metadata_item" "ssh-keys" {
key = "ssh-keys"
value = file(var.pub_google_key)
}
ssh-keys is added to instance.
When I finish, I get
google_compute_instance.webserver[0] (remote-exec): Connecting to remote host via SSH...
google_compute_instance.webserver[0] (remote-exec): Host: 1.1.1.1
google_compute_instance.webserver[0] (remote-exec): User: root
google_compute_instance.webserver[0] (remote-exec): Password: false
google_compute_instance.webserver[0] (remote-exec): Private key: true
google_compute_instance.webserver[0] (remote-exec): Certificate: false
google_compute_instance.webserver[0] (remote-exec): SSH Agent: false
google_compute_instance.webserver[0] (remote-exec): Checking Host Key: false
google_compute_instance.webserver[0]: Still creating... [5m0s elapsed]
Error: timeout - last error: SSH authentication failed (root#35.247.121.86:22): ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain
When I try to connect by ssh from the terminal, I get
ssh -i [PATH_TO_PRIVATE_KEY] [USERNAME]#[EXTERNAL_IP_ADDRESS]
root#1.1.1.1: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
I tried different options to add a key, but I always get forbidden access to the host. What could be wrong?

Answer 1

SSH for Root user is disabled by default on GCP. You will have to use a specific user to connect, you will still have root permissions. If you absolutely must connect using root account which is not recommended I suggest using a pre-built image or start-up scripts where you can enable it as described here, but I will not cover in this answer.
So, to achieve a connection on Terraform with a specific user you need to:
Change the connection user configuration in TF
connection {
user = "alexey"
...
}
Change the metadata SSH KEY to contain the username with the publickey in the format described here.
ssh-rsa [KEY_VALUE] [USERNAME]