Kuma should allow to define empty list of reachableServices

[lukidzi]

What happened?

Sometimes services don't need to communicate with other services and in this case, they might not require changes/observer all services in the infrastructure. Currently, it is not possible to define an empty list of reachable services.
On Kubernetes you can define kuma.io/transparent-proxying-reachable-services: "[]" and in this case, it won't match with any outbound. But, Kuma sees this as a list of service with the name[]. We should define maybe some value/annotation that will allow disabling tracking of all services.

[jakubdyszkiewicz]

A workaround is to put random non-existent service like this:

kuma.io/transparent-proxying-reachable-services: "non-existing-service"

It's because in protobuf [] = nil

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[github-actions]

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[github-actions]

This issue was inactive for 90 days. It will be reviewed in the next triage meeting and might be closed.
If you think this issue is still relevant, please comment on it or attend the next triage meeting.

[github-actions]

This issue was inactive for 90 days. It will be reviewed in the next triage meeting and might be closed.
If you think this issue is still relevant, please comment on it or attend the next triage meeting.

[github-actions]

This issue was inactive for 90 days. It will be reviewed in the next triage meeting and might be closed.
If you think this issue is still relevant, please comment on it or attend the next triage meeting.

[github-actions]

This issue was inactive for 90 days. It will be reviewed in the next triage meeting and might be closed.
If you think this issue is still relevant, please comment on it or attend the next triage meeting.

[lahabana]

Is this any better with MeshService? Is it also possible to have label based reachable services for example to have an entire namespace?

[jakubdyszkiewicz]

Yes, you can use label to select a namespace. We still treat empty reachable-backend-refs as "reach all" I think. I just pinged @lukidzi to make sure we fix it for the new annotation

[lahabana]

@lukidzi can you confirm we can to no service? Also we discussed a mode for MeshService which would require using ReachableServices have we got an issue to track this?

[jakubdyszkiewicz]

for reachable backends we can do this: {}