Handling of Redis Username in ExtAuth and Rate Limiter

[sheidkamp]

Gloo Edge Product

Enterprise

Gloo Edge Version

current

Is your feature request related to a problem? Please describe.

As part of addressing https://github.com/solo-io/gloo-mesh-enterprise/issues/15610, The ExtAuth and RateLimit services were updated to pull the Redis User from the REDIS_USER environment variable.

While we have the ability to set these (separately) with an environment variable via global.extensions.(extAuth|rateLimit).deployment.customEnv[].name, we should consider providing better UX

Describe the solution you'd like

Gloo Mesh handles this by making username part of the secret

Gloo Edge uses a secret to provide the Redis password, and a similar implementation would make sense.

Describe alternatives you've considered

It would be an improvement if we provided a Helm value to set the environment variable, but mirroring the Mesh approach would provide consistency and store the username with the password, which seems natural

Additional Context

This issue affects AWS Elasticache with AUTH,

The Gloo Mesh issue provides additional context