Either set "ssh_skip_nat_mapping" or let Packer select a WinRM port dynamically

[frischke]

In the current version of Packer (0.12.3), the virtualbox-iso builder tries to discover a suitable port for forwarding winrm (and ssh) traffic dynamically. Unfortunately Packer also overwrites an explicitly configured winrm_port with the discovered port, unless ssh_skip_nat_mapping is also set to true (default is false).

As a consequence, the vbox builds will eventually time out since Packer cannot connect to the Virtualbox VM successfully. I suggest to either add the "ssh_skip_nat_mapping": "true" option to the vbox-\<os>.json config files or remove the explicitly configured winrm_port and the corresponding VBox port forwarding rule entirely and let Packer find a suitable port.

Relevant code references in Packer:

• builder/virtualbox/common/step_forward_ssh.go, lines 30 ff.: Unless ssh_skip_nat_mapping is true, it tries to discover a port and if found, configures port forwarding on the vbox vm. The discovered port is stored in the StateBag under the "sshHostPort" key.
• builder/virtualbox/common/ssh.go, lines 16 ff.: Function that fetches port number from the StateBag.
• builder/virtualbox/iso/builder.go, lines 246 ff.: References above function for determining the WinRMPort.
• helper/communicator/step_connect_winrm.go, lines 100 ff.: Reads the winrm port from config, but then overwrites it with the return value of WinRMPort.

[frischke]

Unfortunately, the Packer documentation does not state that ssh_skip_nat_mapping also applies to the WinRM port (see the current Packer doc). I will probably open an issue in the Packer repository regarding this behavior too.

[mwrock]

closing this for now. I removed the winrm port setting alltogether and packer can now connect.