allow users to specificy a topic regexp

[VerstraeteBert]

Signed-off-by: Bert Verstraete [email protected]

Allow users to use a regexp to select the kafka topics they wish to scale from

Checklist

• Commits are signed with Developer Certificate of Origin (DCO - learn more)
• Tests have been added
• A PR is opened to update our Helm chart (repo) (if applicable, ie. when deployment manifests are modified)
• A PR is opened to update the documentation on (repo) (if applicable)
• Changelog has been updated

Fixes #2447

[zroubalik]

@VerstraeteBert any update on this please?

[VerstraeteBert]

@VerstraeteBert any update on this please?

@zroubalik Been quite busy lately, have some time this weekend to write tests etc. :-)

[VerstraeteBert]

Might pick this back up at a later time.

[kriegster108]

@VerstraeteBert could you pick this back up at some point? We would love to have this support as our kafka solution uses a tenant-per-topic pattern and would make our KEDA implementation a lot less complicated with use of regex.

We need this in order to scale to 0 with KEDA because currently we are running KEDA with a minimum of 1 replica and are just passing in consumer group information to our keda configuration. In order to scale to 0 and avoid the race condition that occurs when a brand new topic is created (no offset provisioned in consumer group yet) we need to pass in tons of tenant topics via regex to make this possible, so if we add a new tenant to kafka, we dont have to make a deployment change to all services every time.