Can't clear shared flag of unused network

[Mike Kolesnik]

A network marked as external can be used as a gateway for tenant routers, even though it's not necessarily marked as shared.
If the 'shared' attribute is changed from True to False for such a network you get an error:
Unable to reconfigure sharing settings for network sharetest. Multiple tenants are using it

This is clearly not the intention of the 'shared' field, so if there are only service ports on the network there is no reason to block changing it from shared to not shared.

[Eugene Nikanorov (enikanorov)]

> if there are only service ports on the network there is no reason to block changing it from shared to not shared.

If there are ports on the network belonging to different tenants that means that the network is shared, hence the check.
I think the bug is not valid

[Mike Kolesnik (mkolesni)]

> If there are ports on the network belonging to different tenants that means that the network is shared, hence the check.
> I think the bug is not valid

As I explained, if a network is marked "external" then it can be set as a gateway for routers of other tenants. This creates a port for the router on the network.
If I mark this network as shared or not shared this doesn't affect these ports or the usage of the network as a gateway.

The problem is that if there are no instance ports on the network, the "shared" mark can't be removed even though it's not used by any instance.

For example, if I have a non-external network with no instance ports on it I can update it to shared and then immediately update to non-shared, this will work.
However, if I have an external network that is being used as a gateway then I can update it to shared but immediately updating to non-shared will fail because of the router port, and this is the cause of the bug.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/82352

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/82352
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=7a2053c7a27bdec02e97b46736c5fcce5f2d053a
Submitter: Jenkins
Branch: master

commit 7a2053c7a27bdec02e97b46736c5fcce5f2d053a
Author: Mike Kolesnik <email address hidden>
Date: Sun Mar 23 15:48:42 2014 +0200

    Allow unsharing a network used as gateway/floatingip

    If network has ports that connect it as gateway to another network, such
    as an external network, or "floating ip" ports it should still be
    possible to "unshare" it since these ports represent usage of the
    network as an external network, not as a VM data network.

    Change-Id: Ic33ae7ac193e4fc9fe06a4cfd579a4aacf0e6354
    Closes-bug: #1293184

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/icehouse
Review: https://review.openstack.org/111721

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/111721
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=161d465305777226a15ced334acfd06142597f85
Submitter: Jenkins
Branch: stable/icehouse

commit 161d465305777226a15ced334acfd06142597f85
Author: Mike Kolesnik <email address hidden>
Date: Sun Mar 23 15:48:42 2014 +0200

    Allow unsharing a network used as gateway/floatingip

    If network has ports that connect it as gateway to another network, such
    as an external network, or "floating ip" ports it should still be
    possible to "unshare" it since these ports represent usage of the
    network as an external network, not as a VM data network.

    Change-Id: Ic33ae7ac193e4fc9fe06a4cfd579a4aacf0e6354
    Closes-bug: #1293184
    (cherry picked from commit 7a2053c7a27bdec02e97b46736c5fcce5f2d053a)