Disallow leading digit or embedded spaces in application names

[stooke]

The current UI validates names via a regex that allows leading digits and embedded spaces.
I would like to remove both of those; leading digits cause issues with DNS in Kubernetes, and spaces may cause unknown problems at some point.

First, I would like to ask for the actual naming requirements; my proposed change is just a common-sense guess.

The "ideal" architecture disconnects the application name (or space name, etc.) from the code, and passes through an identifier such as a UUID or other short form. Again, this issue is just a bandaid ona deeper problem.

current regex:
const pattern = /^[a-zA-Z0-9][a-zA-Z0-9-_\s]{2,38}[a-zA-Z0-9]$/;

proposed regex:
const pattern = /^[a-zA-Z][a-zA-Z0-9-_]{2,38}[a-zA-Z0-9]$/;

[stooke]

Kubernetes:
https://github.com/kubernetes/community/blob/master/contributors/design-proposals/architecture/identifiers.md

[joshuawilson]

I'm guessing this is the Space name?

[stooke]

Yes, the regex is very permissive. If we were passing UUIDs throughout, this would be fine, but we pass names, and not just names, names with extra strings tacked on - so it's hard to determine the exact limitations on any given identifier.

In particular, the existing pattern allows spaces, and there have been issues (resolved) around spaces. There may still be more undiscovered issues - it's not clear.

[jiekang]

Related #3503

[jiekang]

Closing as fix has been merged.