Unable to launch downgrade if label version already set to dest

[TeddyAndrieux]

Component:

'lifecycle'

What happened:

If for whatever reason (downgrade already failed or ....) all the node already have the label version set to the destination version then downgrade fail.

NOTE: The label version is set before downgrading the node so this version does not necessarily represent the running version but the desired version!

[root@test-solution ~]# kubectl get node -o go-template='{{range .items}}{{index .metadata.labels "metalk8s.scality.com/version"}}{{end}}{{printf "\n"}}'
2.4.2
[root@test-solution ~]# /srv/scality/metalk8s-2.4.3/downgrade.sh --destination-version 2.4.2
> Performing Pre-Downgrade checks... fail [45s]

Failure while running step 'Performing Pre-Downgrade checks'

Command: precheck_downgrade

Output:

<< BEGIN >>
[ERROR   ] Failure!
bootstrap_master:
----------
          ID: Invalid saltenv "metalk8s-2.4.3" consider using "metalk8s-2.4.2"
    Function: test.fail_without_changes
      Result: False
     Comment: Failure!
     Started: 08:44:54.030307
    Duration: 2.577 ms
     Changes:   
----------
          ID: Node bootstrap already in version 2.4.2
    Function: test.succeed_without_changes
      Result: True
     Comment: Success!
     Started: 08:44:54.033391
    Duration: 0.728 ms
     Changes:   

Summary for bootstrap_master
------------
Succeeded: 1
Failed:    1
------------
Total states run:     2
Total run time:   3.305 ms
time="2020-05-15T08:44:54Z" level=fatal msg="execing command in container failed: command terminated with exit code 1"
<< END >>

This script will now exit

What was expected:

This pre-check shouldn't fail if the script version is higher than ALL nodes versions

Steps to reproduce

Set label metalk8s.scality.com/version of all nodes to destination version and try to downgrade

Resolution proposal (optional):

Check for saltenv version to be higher than all nodes version and not strictly equal

---

Workaround:

Set metalk8s.scality.com/version of at least one node to the current running version

E.g.: Downgrading from 2.4.3 to 2.4.2 just set one node version to 2.4.3 and then you can run the downgrade script again