cannot ssh into instance created from sourceImage "google_compute_instance_from_machine_image"

Question

I am creating an instance from a sourceImage, using this terraform template:

resource "tls_private_key" "sandbox_ssh" {
  algorithm = "RSA"
  rsa_bits = 4096
}

output "tls_private_key_sandbox" { value = "${tls_private_key.sandbox_ssh.private_key_pem}" }

locals {
  custom_data1 = <<CUSTOM_DATA
#!/bin/bash
CUSTOM_DATA
}

resource "google_compute_instance_from_machine_image" "sandboxvm_test_fromimg" {
  project = "<proj>"
  provider = google-beta
  name = "sandboxvm-test-fromimg"
  zone = "us-central1-a"
  tags         = ["test"]

  source_machine_image = "projects/<proj>/global/machineImages/sandboxvm-test-img-1"

  can_ip_forward = false

  labels = {
    owner = "test"
    purpose = "test"
    ami = "sandboxvm-test-img-1"
  }

  metadata = {
   ssh-keys = "${var.sshuser}:${tls_private_key.sandbox_ssh.public_key_openssh}"
 }

  network_interface {
    network = "default"
    access_config {
      // Include this section to give the VM an external ip address
    }
  }

  metadata_startup_script = local.custom_data1
}

output "instance_ip_sandbox" {
  value = google_compute_instance_from_machine_image.sandboxvm_test_fromimg.network_interface.0.access_config.0.nat_ip
}

output "user_name" {
    value       = var.sshuser
}

I can't even ping / netcat, neither the private or public IP of the VM created. Even the "serial port" ssh, passed inside custom script helps.

I'm suspecting, that since it is a "google beta" capability, is it even working / reliable? Maybe we just can't yet, create VMs ie GCEs from "SourceImages" in GCP, Unless proven otherwise, with a simple goof-up not very evident in my TF.

Answer 1

I could solve it actually, and all this somewhere sounds very sick of GCE. Problem was while creating the base image, the instance I had chosen has had the following:

#sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.6 2
#sudo update-alternatives --install /usr/bin/python3 python /usr/bin/python3.7 1

Maybe I should try with "python3" instead of "python", but when instantiating GCEs basis this MachineImage, it looks for a rather deprecated "python2.7" and not "python3" and complained of missing / unreadable packages like netiplan etc.

Commenting the "update-alternatives" and installing python3.6 and python3.7 explicitly did the trick!