Tests on destroying one controller and verification l3 agent behaviour and pings between VMs fail for MOS 8.0

[Alexander Gromov]

Repository: https://github.com/Mirantis/mos-integration-tests

Tests "Shut down non-primary controller and check l3-agent work" and "Shut down primary controller and check l3-agent" fail for MOS 8.0 with the following message:
TimeoutExpired: Timeout of 180 seconds expired waiting for SSH command: ping -c1 8.8.8.8 && ping -c1 192.168.4.4 && ping -c1 10.109.27.133 && ping -c1 192.168.3.4 completed with 0 exit code

Testrail links:
https://mirantis.testrail.com/index.php?/tests/view/5269880
https://mirantis.testrail.com/index.php?/tests/view/5269878

Sometimes the following error can be found:
Failed: There are routers on l3_agent(ea1db255-eca7-4628-83b0-89116071d941): router04(11d36eaa-44e4-4da3-aba1-5c09ff440dbf) router01(7e9d508b-6c34-4cb9-97fa-496b5758e0ab)

Environment: 3 controllers + 2 computes-cinder VxLAN + L2POP

Milestone: Mirantis OpenStack 8.0-updates

[Alexander Gromov (agromov)]

There was a problem with implementation of ssh connection.
Review link: https://review.gerrithub.io/#/c/275328/

[Alexander Gromov (agromov)]

The problem exists after commit.

[Alexander Gromov (agromov)]

There is also a problem with check_no_routers_on_l3_agent function.

[Alexander Gromov (agromov)]

Review link: https://review.gerrithub.io/#/c/277093/