From a30dc4d68873a1dbf6d5d3d90271a38481690297 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Harald=20Jens=C3=A5s?= Date: Wed, 9 Sep 2020 04:55:43 +0200 Subject: [PATCH] Net attr: Sort segments without name attribute first Useing get_attr, pulling index 0 in the segments list of a network to associate the a subnet with the "first" segment is useful since the "first" segment is created by neutron behind the scenes on network create. A resource reference cannot be used since the "first" segment is'nt a heat resource. The issue is the order of the segments list is'nt reliable. On stack update index 0 may be a different segment, and we end up trying to update the segment_id for a subnet. Changeing the segment association is not allowed, so the stack update fails. While not perfect, sorting the list so that segments where name is None comes first will ensure that index 0 can be used. The template author should ensure segments defined in the heat template all have a names set, so that only the segment creted implicitly by neutron have 'None' name. Closes-Bug: #1894920 Change-Id: I097aba2a97144327bec188e6c71629d0f6c95901 (cherry picked from commit 539b2a4c4993787db0cd71750d3d159e584deccb) --- heat/engine/resources/openstack/neutron/net.py | 7 ++++++- ...ribute-semi-predictable-b40a869317d053cc.yaml | 16 ++++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) create mode 100644 releasenotes/notes/os-neutron-net-segments-attribute-semi-predictable-b40a869317d053cc.yaml diff --git a/heat/engine/resources/openstack/neutron/net.py b/heat/engine/resources/openstack/neutron/net.py index 62a19e1ff7..d0d2ebd8dd 100644 --- a/heat/engine/resources/openstack/neutron/net.py +++ b/heat/engine/resources/openstack/neutron/net.py @@ -284,8 +284,13 @@ class Net(neutron.NeutronResource): if self.resource_id is None: return if name == self.SEGMENTS: - return [segment.to_dict() for segment in list(self.client( + segments = [segment.to_dict() for segment in list(self.client( 'openstack').network.segments(network_id=self.resource_id))] + # Sort segments without name attribute first. + # See bug: https://bugs.launchpad.net/tripleo/+bug/1894920 + segments.sort(key=lambda s: s['name'] is not None) + return segments + attributes = self._show_resource() return attributes[name] diff --git a/releasenotes/notes/os-neutron-net-segments-attribute-semi-predictable-b40a869317d053cc.yaml b/releasenotes/notes/os-neutron-net-segments-attribute-semi-predictable-b40a869317d053cc.yaml new file mode 100644 index 0000000000..f398d89288 --- /dev/null +++ b/releasenotes/notes/os-neutron-net-segments-attribute-semi-predictable-b40a869317d053cc.yaml @@ -0,0 +1,16 @@ +--- +fixes: + - | + The ordering in the list of segments returned by ``OS::Neutron::Net`` + resources is not predictable. Stack updates changeing attributes + of the network can cause the list of segments to shift. + + The ordering is now slightly more predictable, segments with name=``None`` + are now placed first in the list. This doesn't guarantee the order, but + typically only the segment implicitly created by neutron has no name + attribute set. The template author should ensure other segments on the + network does have a name set, so that the implicit segment will always be + index 0. Resolving attributes of the implcitly created segment on the + network resource can then predictibly happen using index 0. See `bug: + 1894920 `_. +