Layer UUID hook

[mattiagiupponi]

The current generation of the UUID for the Layers is based on those two lines:

geonode/geonode/layers/models.py

Line 620 in 0a82a14

instance.uuid = str(uuid.uuid1())

geonode/geonode/upload/upload.py

Line 596 in 0a82a14

layer_uuid = str(uuid.uuid1())

We want to let the UUID creation be pluggable and let the user use his own UUID generator based on their needs.

geonode/geonode/layers/models.py

Lines 619 to 623 in 36c28d6

	logger.debug("handling UUID In pre_save_layer")
	if hasattr(settings, 'LAYER_UUID_HANDLER') and settings.LAYER_UUID_HANDLER != '':
	logger.debug("using custom uuid handler In pre_save_layer")
	from geonode.layers.utils import get_uuid_handler
	instance.uuid = get_uuid_handler()(instance).create_uuid()

And is enough to add this config in settings.py by specifying the object that is responsible to manage the new UUID

LAYER_UUID_HANDLER = "mymodule.myfile.MyObject"

More information related to the configuration are available in this PR