Nova-compute verifier

So far, the “reboot” and “shutdown” actions are supported and they both perform the same set of checks.

• check running VMs

• check availability zones

$ juju-verify reboot --unit nova-compute/0
===[nova-compute/0]===
Checks:
[OK] check_affected_machines check passed
[OK] check_has_sub_machines check passed
[OK] Unit nova-compute/0 is running 0 VMs.
[OK] Empty Availability Zone check passed.

Result: OK (All checks passed)

check running VMs

This simple check verifies that the unit(s) about to be reboot/shutdown do not host any virtual machines. In this case, the following result message will be present.

[OK] Unit nova-compute/0 is running 0 VMs.

If the VMs are present, the verifier will fail and user has to manually migrate those VMs away from the unit(s) intended for reboot/shutdown. The failure result message is basically the same as in the previous case.

[FAIL] Unit nova-compute/0 is running 2 VMs.

check availability zones

This check verifies that after reboot/shutdown of selected nova-compute units, availability zones to which these units belong wont be left empty. This is what the result message looks like after a successful check.

[OK] Empty Availability Zone check passed.

If availability zone remains empty after reboot/shutdown unit(s), the result message will be as follows.

[FAIL] Removing these units would leave following availability zones empty: {'nova'}

This check takes into consideration only availability zones that are affected by the unit reboot/shutdown, there may be other empty availability zones within the cluster.