The GCE bakery configuration allows for setting the default network and zone and whether to use the public IP address of the VM used for baking the image.
For example, to set the default zone:
hal config provider google bakery edit --network $YOUR_NETWORK
You can also define custom base images:
hal config provider google bakery base-image add $BASE_IMAGE \ --source-image $GCE_VM_IMAGE_NAME \ --short-description this-is-my-image \ --detailed-description 'There are many like it, but this one is mine.' \ --package-type deb
These images are used to dynamically populate the bake stage UI:
The options are fully-described here: here