Disallow updating baymodel when it is referenced

[hongbin]

It is very dangerous to update a baymodel when it is referenced by bay(s). Consider the following workflow as an example:

$ magnum baymodel-create --name k8sbaymodel \
                       --image-id fedora-21-atomic-5 \
                       --keypair-id testkey \
                       --external-network-id public \
                       --dns-nameserver 8.8.8.8 \
                       --flavor-id m1.small \
                       --docker-volume-size 5 \
                       --network-driver flannel \
                       --coe kubernetes
$ magnum bay-create --name k8sbay --baymodel k8sbaymodel --node-count 1
$ magnum baymodel-update bccc2a4b-fa19-42c1-8327-6d2b026f6f9a replace coe=swarm

The COE changes after a bay is created. When the bay is updated, it will use a swarm templates to update a k8s bay which is bad.

We should disallow updating a baymodel if it is referenced by one or multiple bays.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/266420

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/266420
Committed: https://git.openstack.org/cgit/openstack/magnum/commit/?id=aa5c392f0ab0604817ab6354a19d00b475ed9807
Submitter: Jenkins
Branch: master

commit aa5c392f0ab0604817ab6354a19d00b475ed9807
Author: houming-wang <email address hidden>
Date: Tue Jan 12 04:52:19 2016 -0500

    Disallow updating baymodel when it is referenced

    It is very dangerous to update a baymodel when it is referenced by
    bay(s). We should disallow updating a baymodel if it is referenced
    by one or multiple bays. A BayModelReferenced exception will be raised
    when do this action.

    DocImpact
    Closes-Bug: #1517259
    Change-Id: I6c6cd1eebbb6e1f4b5e1657d3909b1bc8d287a35

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/magnum 2.0.0 release.