Update mustgather.go

[danielyeap]

(1) ability to send local files into the mustgather pods (needed for custom mustgather tool)
(2) ability to run the mustgather pod using a user-defined user (instead of fixed to the "default" user/serviceaccount)

[openshift-ci]

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[openshift-ci]

Hi @danielyeap. Thanks for your PR.

I'm waiting for a openshift member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[danielyeap]

Hi @ardaguclu @deads2k
Anything pending on my side for this review?
Sorry...this is my first time.
Thanks.

[ardaguclu]

@danielyeap thank you for spending time on this PR. However, I don't think we can merge the changes in here.
The reasons are:

• Adding a new flag would require strong justification and even the ones that are marked as hidden is there for a reason. Especially, there are multiple images exist for must-gather, we can't add new flags without notifying the all image owners.
• We have to be backwards compatible. All the changes are only be applied if they are working against older images, OCP version, k8s version etc. I saw a couple of changes are not backwards compatible.

I hope it makes sense. Thanks again.

[danielyeap]

Hi @ardaguclu
Thanks for spending time to respond.

I hope you can help with a few questions:
(1) Can you point me to all the must-gather images?
(2) What are the changes that are not backward-compatible?

Lastly, while there are 2 features added through this code change, the truly critical one is the ability to send files into the mustgather pod.

Any idea whether that is a planned feature for the future please?

Thanks again!