support draining multiple node

[andrewhu-hcl]

refactor the drainNode function to support draining multiple node

Signed-off-by: Andrew Hu [email protected]

What this PR does / why we need it: Current node drain experiment, if the targetNodes is provided, it will get all the node names by split the comma and check each node status. However, during the node drain stage, it just passed the targetNodes into the node drain command, didn’t check if a string contained multiple nodes with comma-separated. So it will cause an error if we specify the targetNodes as multiple node name list by comma-separated. It will be great if it can support draining the multiple nodes.

Which issue this PR fixes: fixes #3343

Special notes for your reviewer:

Checklist:

• [ ] Fixes #3343
• [ ] PR messages has document related information
• [ ] Labelled this PR & related issue with breaking-changes tag
• [ ] PR messages has breaking changes related information
• [ ] Labelled this PR & related issue with requires-upgrade tag
• [ ] PR messages has upgrade related information
• [ ] Commit has unit tests
• [ ] Commit has integration tests
• [ ] E2E run Required for the changes

[calebxu-hcl]

Thanks for the feedback @uditgaurav, I think I've addressed all three items you mentioned above. Please advise if there's still any concerns.

[uditgaurav]

Thanks, @andrewhu-hcl for being patient! Can we also add the logs of experiments with successful execution for multiple nodes?