- `use_iap` (bool) - Whether to use an IAP proxy. Prerequisites and limitations for using IAP: - You must manually enable the IAP API in the Google Cloud console. - You must have the gcloud sdk installed on the computer running Packer. - You must be using a Service Account with a credentials file (using the account_file option in the Packer template) - You must add the given service account to project level IAP permissions in https://console.cloud.google.com/security/iap. To do so, click "project" > "SSH and TCP resoures" > "All Tunnel Resources" > "Add Member". Then add your service account and choose the role "IAP-secured Tunnel User" and add any conditions you may care about. - `iap_localhost_port` (int) - Which port to connect the local end of the IAM localhost proxy to. If left blank, Packer will choose a port for you from available ports. - `iap_hashbang` (string) - What "hashbang" to use to invoke script that sets up gcloud. Default: "/bin/sh" - `iap_ext` (string) - What file extension to use for script that sets up gcloud. Default: ".sh" - `iap_tunnel_launch_wait` (int) - How long to wait, in seconds, before assuming a tunnel launch was successful. Defaults to 30 seconds for SSH or 40 seconds for WinRM.