This doesn't add/change an appliance, it only creates a basic Debian packer template. It uses the official Debian cloud image as a base image.
User debian (password debian) is the root user replacement, it is allowed to run passwordless sudo.
User gns3 (password gns3) is an unprivileged user.
Currently it doesn't add much to the cloud image, so it doesn't make much sense to create an appliance from this. The idea is, to use it as a base for other appliances.
This doesn't add/change an appliance, it only creates a basic Debian packer template. It uses the official Debian cloud image as a base image.
User debian (password debian) is the root user replacement, it is allowed to run passwordless sudo. User gns3 (password gns3) is an unprivileged user.
Currently it doesn't add much to the cloud image, so it doesn't make much sense to create an appliance from this. The idea is, to use it as a base for other appliances.
Sorry, I don't have time to help on issue https://github.com/GNS3/gns3-registry/issues/697, but maybe this Debian packer script helps.