Remove DNS-1123 validation of usernames and groups

[richardmarshall]

k8s doesn't require user or group names to be DNS-1123 labels so there isn't a need to enforce or transform these values to conform to that format.

To that end this PR removes the regexp check which validates DNS-1123 and removes the string replacement of @s in SessionName.

Also of note that the current regex is missing start and end of line anchors so the validation is only ensuring that a group or user contains a sub-string that is a valid DNS-1123 label.

The second change does have impacts on existing usage of the {{SessionName}} template value which could break rolebindings for users who are making use of this value and have email addresses for session names.

I see a few ways this could be addressed and am happy to update the PR to reflect a desired path for this.

• Liberal documentation updates to warn users of the change.
• Toggle the change on a server flag (something along the lines of --legacy-session-name=true)
• Creating a new template variable ({{SessionNameRaw}}) that doesn't do the replacement and leave the existing behavior for {{SessionName}} in place.

Related to #80

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[richardmarshall]

/assign @mattmoyer

[micahhausler]

I don't have an issue with removing the regex, but the {{SessionName}} a breaking change is a no-go.

• Creating a new template variable ({{SessionNameRaw}}) that doesn't do the replacement and leave the existing behavior for {{SessionName}} in place.

I like this idea a lot and would happily accept this

[richardmarshall]

breaking change is a no-go.

I expected that but wanted to seed discussion with the lowest effort code change 😄

I like this idea a lot and would happily accept this

Great, will update the code and add some documentation for the new template variable.

[richardmarshall]

@micahhausler Updated, PTAL

[nckturner]

/lgtm

[richardmarshall]

@micahhausler @nckturner Anything else needed on my end to help move this forward?

[micahhausler]

/approve
/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: micahhausler, richardmarshall

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