packer.json

{
  "builders": [
    {
      "type": "googlecompute",
      "account_file": "credentials.json",
      "project_id": "<GCP_PROJECT_NAME>",
      "zone": "europe-west2-a",
      "source_image_family": "ubuntu-1604-lts",
      "ssh_username": "packer",
      "image_name": "nginx-{{timestamp}}",
      "image_family": "webserver"
    }
  ],
  "provisioners": [
      {
        "type": "file",
        "source": "./index.html",
        "destination": "/tmp/index.html"
      },
      {
        "type": "shell",  
        "script": "setup.sh"
      }
  ]
}