Ironic virt driver should not JSON encode traits in instance_info

[Mark Goddard]

As of queens, the ironic virt driver pushes traits set on the flavor to the ironic node's instance_info during instance spawn. This list of traits is currently encoded as a JSON string, inside the JSON-encoded instance_info. We should not use this double layer of JSON encoding, as ironic expects instance_info.traits to be a list.

Steps to reproduce
==================

Add a trait to an ironic node:

openstack baremetal node add trait <node> <trait>

Add a required trait to a flavor:

openstack flavor set <flavor> --property 'trait:<trait>=required'

Create an instance using this flavor:

openstack server create ...

Expected result
===============

Nova sets the node's instance_info.traits to a list containing the trait.

Actual result
=============

Nova sets the node's instance_info.traits to a JSON-encoded string containing a list containing the trait.

Environment
===========

Nova stable/queens @ 01b756f960ed19ab801994d08d749dd94d729a22

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/543574

[Matt Riedemann (mriedem)]

How is instance_info.traits used in nova? What impact does this have? What doesn't work if we don't fix this?

[Matt Riedemann (mriedem)]

(1:29:28 PM) mgoddard: mriedem: the scheduling works, but any flavor-requested traits won't be pushed to the ironic node's instance_info. These are not yet used by ironic, but will be used in future for some capabilities-like things
(1:29:49 PM) mriedem: mgoddard: if they aren't used in ironic in queens, then it's not something worth holding up rc2 IMO

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/543574
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=54713a834f2a0e5b55b8f77c601ff35eb74b9b09
Submitter: Zuul
Branch: master

commit 54713a834f2a0e5b55b8f77c601ff35eb74b9b09
Author: Mark Goddard <email address hidden>
Date: Mon Feb 12 18:35:33 2018 +0000

    Don't JSON encode instance_info.traits for ironic

    As of queens, the ironic virt driver pushes traits set on the flavor to
    the ironic node's instance_info during instance spawn. This list of
    traits is currently encoded as a JSON string, inside the JSON-encoded
    instance_info. We should not use this double layer of JSON encoding, as
    ironic expects instance_info.traits to be a list.

    This change removes the nested JSON encoding when setting
    node.instance_info.traits.

    Change-Id: I1f3f96f7ef310022accde67cab1ae415bbc3c292
    Closes-Bug: #1748942

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/queens
Review: https://review.openstack.org/545037

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/545037
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=d0c10db716c6d5a90ed329ba4806535ec91b34c0
Submitter: Zuul
Branch: stable/queens

commit d0c10db716c6d5a90ed329ba4806535ec91b34c0
Author: Mark Goddard <email address hidden>
Date: Mon Feb 12 18:35:33 2018 +0000

    Don't JSON encode instance_info.traits for ironic

    As of queens, the ironic virt driver pushes traits set on the flavor to
    the ironic node's instance_info during instance spawn. This list of
    traits is currently encoded as a JSON string, inside the JSON-encoded
    instance_info. We should not use this double layer of JSON encoding, as
    ironic expects instance_info.traits to be a list.

    This change removes the nested JSON encoding when setting
    node.instance_info.traits.

    Change-Id: I1f3f96f7ef310022accde67cab1ae415bbc3c292
    Closes-Bug: #1748942
    (cherry picked from commit 54713a834f2a0e5b55b8f77c601ff35eb74b9b09)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 17.0.0.0rc2 release candidate.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 18.0.0.0b1 development milestone.