[Tempest] Floating IP and static IP should be in different CIDRs

[Rodolfo Alonso]

In "test_connectivity_dvr_and_no_dvr_routers_in_same_subnet", both the floating IP and the static IP are in the same CIDR. This implies the GW for both subnets is the same and the traffic can't be router properly.

We should check first the external network CIDR and assign a non overlapping one to the private subnet.

Logs: http://paste.openstack.org/show/788916/

BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1795638

[Slawek Kaplonski (slaweq)]

And patch proposed to address this https://review.opendev.org/#/c/704768/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/704768
Committed: https://git.openstack.org/cgit/openstack/neutron-tempest-plugin/commit/?id=3e1921b48ad485669b3ab42002d08eb49f34f468
Submitter: Zuul
Branch: master

commit 3e1921b48ad485669b3ab42002d08eb49f34f468
Author: ccamposr <email address hidden>
Date: Wed Jan 29 11:10:05 2020 +0100

    Use different CIDRs for private and public subnets

    In test "test_connectivity_dvr_and_no_dvr_routers_in_same_subnet", as
    reported in the bug, the public IP (floating IP) and the private IP
    are in the same CIDR. This breaks the isolation between networks.

    Co-Authored-By: Rodolfo Alonso Hernandez <email address hidden>

    Closes-Bug: #1861282

    Change-Id: I39ca6474068d2e169dff1b81d2a0c71a8361c01f

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron-tempest-plugin 0.8.0 release.