invalid: metadata.labels for createBy when SSO subject does not start with alphanumeric charecters

[ermeaney]

Summary

Submitting a workflow from the UI when SSO is enabled fails and throws a kubernetes validation error

Diagnostics

What Kubernetes provider are you using?
EKS v1.18
What version of Argo Workflows are you running?
reproduced in 2.12.2 and 2.12.4

The error we receive is

Unsuccessful HTTP response: Workflow.argoproj.io "legacyjobs-ghbc4" is invalid: metadata.labels: Invalid value: "_Cjks_k4UFqRHnV8IEbPNXVrhpAeJZa6It-6cxYHGD8": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue', or 'my_value', or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?'):  Reload

where _Cjks_k4UFqRHnV8IEbPNXVrhpAeJZa6It-6cxYHGD8 is the subject name in user info

looking at argo/workflow/creator/creator.go

It appears that some of this was addressed in a recent PR, but a change to the dnsFriendly function something like this would probably address the problem we are seeing

func dnsFriendly(s string) string {
	value := regexp.MustCompile("[^-_.a-z0-9A-Z]").ReplaceAllString(s, "-")
        value = regexp.MustCompile("^[^a-z0-9A-Z]*").ReplaceAllString(value, "")
	if len(value) > 63 {
		value = value[len(value)-63:]
	}
	value = strings.TrimLeft(value, "-")
	return value
}

Since that should satisfy the regex used for validation in the above error message

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[alexec]

would you like to submit a PR to fix?

[alexec]

https://stackoverflow.com/questions/106179/regular-expression-to-match-dns-hostname-or-ip-address

I think we must remove underscores completely, and trim hyphens from both ends. This bit of code has produced many bugs for its size.

[ermeaney]

I can see if I can work out a PR, I am seeing if I can get the compile to run so I can try and write some tests for this also.

[ermeaney]

Added a PR with fixes to clean the beginning and ends of the creator label, and added tests for it

Let me know if there is anything else

[simster7]

This fix is out on https://github.com/argoproj/argo/releases/tag/v2.12.5