OpenStack Compute (nova)

os_region_name an unnecessary required option for placement

Bug #1751692 reported by Sam Morrison on 2018-02-26

This bug affects 2 people

Affects		Status	Importance	Assigned to	Milestone
	OpenStack Compute (nova)	Fix Released	Low	iain MacDonnell

Bug Description

When configuring placement service for nova-computes it is required to put in the region name for the placement services.

When talking to other services like neutron or cinder specifying a region name isn't required and if you just have 1 region (possibly the most common type of installation?) then it will pick that.

Would be nice if we didn't have to specify the region for placement too.

Code is in nova/compute/manager.py

        # NOTE(sbauza): We want the compute node to hard fail if it won't be
        # able to provide its resources to the placement API, or it will not
        # be able to be eligible as a destination.
        if CONF.placement.os_region_name is None:
            raise exception.PlacementNotConfigured()

Tags:

Takashi Natsume (natsume-takashi) on 2018-03-08

tags:

added: placement

Revision history for this message

Chris Dent (cdent) wrote on 2018-03-12:

Yeah, this looks a bit overly aggressive. Is there a non-optional option that we can use? Would auth_url work or is that plugin dependent?

Changed in nova:
status:	New → Confirmed

Revision history for this message

Sylvain Bauza (sylvain-bauza) wrote on 2018-03-12:

When I introduced that conditional, it was from a upgrade perspective where Newton computes were able to talk to Placement optionally, but where Ocata computes were *needing* to be able to connect to Placement.

During the upgrade to Ocata, there could be chances that operators would miss amending nova.conf in order to make compute nodes able to talk to Placement, and we really wanted to make that hard-failing.

Now that Placement is heavily used in Rocky, with a lot of assertions about the fact that computes can talk to Placement API, I feel it's no longer required to keep such conditional and just remove it entierly.

Changed in nova:
importance:	Undecided → Low
status:	Confirmed → Triaged
tags:	added: low-hanging-fruit

Digambar (digambarpatil15) on 2018-03-21

Changed in nova:
assignee:	nobody → Digambar (digambarpatil15)

Revision history for this message

iain MacDonnell (imacdonn) wrote on 2018-03-26:

Note that placement.os_region_name is (now) a deprecated option too. Agree with Sylvain. Digambar, will you be submitting a change for this?

iain MacDonnell (imacdonn) on 2018-03-31

Changed in nova:
assignee:	Digambar (digambarpatil15) → iain MacDonnell (imacdonn)

Revision history for this message

OpenStack Infra (hudson-openstack) wrote on 2018-03-31: Fix proposed to nova (master)

Fix proposed to branch: master
Review: https://review.openstack.org/558089

Changed in nova:
status:	Triaged → In Progress

Revision history for this message

OpenStack Infra (hudson-openstack) wrote on 2018-04-18: Fix merged to nova (master)

Reviewed: https://review.openstack.org/558089
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=b3c3f2fda883750736bb16d3bb34fd446cc0190a
Submitter: Zuul
Branch: master

commit b3c3f2fda883750736bb16d3bb34fd446cc0190a
Author: imacdonn <email address hidden>
Date: Tue Apr 17 18:57:24 2018 +0000

Remove placement config check

    Removes a check that prevented compute from starting when config option
    placement.[os_]region_name was not set. The check was not appropriate
    since that option is not (otherwise) required. The check was originally
    added to catch upgrades to Ocata, where placement (newly) needed to be
    configured. Since we're well past that point now, the check is no longer
    necessary.

Change-Id: I973180d6a384b32838ab61d4e6aaf73c255fd116
Closes-Bug: 1751692