From be9ecc12823607b4709b64408aee137bfdfc7d01 Mon Sep 17 00:00:00 2001 From: Chad Smith Date: Sun, 1 Jul 2018 16:46:23 -0600 Subject: update_metadata: a datasource can support network re-config every boot Very basic type definitions are now defined to distinguish 'boot' events from 'new instance (first boot)'. Event types will now be handed to a datasource.update_metadata method which can determine whether to refresh its metadata and re-render configuration based on that source event. A datasource can 'subscribe' to an event by setting up the update_events attribute on the datasource class which describe what config scope is updated by a list of matching events. By default datasources will have the following update_events: {'network': [EventType.BOOT_NEW_INSTANCE]} This setting says the datasource will re-write network configuration only on first boot of a new instance or when the instance id changes. New methods are now present on the datasource: - clear_cached_attrs: Resets cached datasource attributes to values listed in datasource.cached_attr_defaults. This is performed prior to processing a fresh metadata process to avoid keeping old/invalid cached data around. - update_metadata: accepts source_event_types to determine if the metadata should be crawled again and processed --- cloudinit/event.py | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 cloudinit/event.py (limited to 'cloudinit/event.py') diff --git a/cloudinit/event.py b/cloudinit/event.py new file mode 100644 index 00000000..f7b311fb --- /dev/null +++ b/cloudinit/event.py @@ -0,0 +1,17 @@ +# This file is part of cloud-init. See LICENSE file for license information. + +"""Classes and functions related to event handling.""" + + +# Event types which can generate maintenance requests for cloud-init. +class EventType(object): + BOOT = "System boot" + BOOT_NEW_INSTANCE = "New instance first boot" + + # TODO: Cloud-init will grow support for the follow event types: + # UDEV + # METADATA_CHANGE + # USER_REQUEST + + +# vi: ts=4 expandtab -- cgit v1.2.3