Added feature: UUID obfuscation in URI label with URI_METRICS_DETAILED enabled

[comemaryvallee]

Motivation

Monitor metrics per realms without constraint of high cardinality due to the presence of UUIDs in the URI label.

What

Added the option to replace user's or client's UUID value in the URI label to a generic {id} value even when the URI_METRICS_DETAILED system variable is set to true.

Why

Needed to be able to monitor metrics with the realm name value present in the URI label but without UUIDs values, due to its high cardinality. The keycloak-metrics-spi evolution added the obfuscation of UUIDs only with the obfuscation of realm name value.

How

By adding a check for a URI_METRICS_UUID_HIDED system variable set to true & by adding "users" value to the condition of UUID obfuscation.

Checklist:

• Code has been tested locally by PR requester
• Changes have been successfully verified by another team member

Additional Notes

Modified the README.md to add the description of this feature.

[pb82]

thanks @comemaryvallee, that seems very useful. It reduces cardinality but also avoids leaking UUIDs. Is this something you're also interested in @CathalOConnorRH ?

[CathalOConnorRH]

thanks @comemaryvallee, that seems very useful. It reduces cardinality but also avoids leaking UUIDs. Is this something you're also interested in @CathalOConnorRH ?

Hey @pb82 This might be something we could use alright, let me know if you would like me to test this change.

[MaksymAtVgs]

@CathalOConnorRH I'm interested in this changes too, any chances that this PR get merged to the master? And when is the next release expected?