Cross Namespace Service Support about voyager HOT 4 CLOSED

@stevenpall thanks for explaining your use-case. I think it will be an useful feature to have. PRs are welcome. If you are interested, we can discuss the design. I think it will be similar to passing an array of services with weights.

As far as the original question though, for my own knowledge and for anyone searching for this answer later, does "cross namespace service support" simply mean that one can route to different namespaces in the same config?

Yes. If you provide the servicename as svc_name.ns_name, then service name will resolved accordingly. This allows you to use ingress from one namespace and service from another namespace.

from voyager.

@stevenpall , currently it is not possible to assign weight directly. This will actually require changes in the YAML format so that multiple services can be defined for a single endpoint.

But if you are looking to use the canary deployment model, you might be interested in https://kubernetes.io/docs/user-guide/managing-deployments/#canary-deployments . This will work with voyager.

Let me know if you have more questions.

from voyager.

Thanks for the info. I have looked at the canary deployment model, though two issues with it stand out to me for this use case.

The first is that services would not be namespaced, so service discovery becomes more complicated (i.e. having to refer to a service as my-app-feature vs. just my-app).

The other issue is that the percentage of traffic a canary deployment receives is dependant upon the number of replicas of the service in question. This number could change dynamically if horizontal pod autoscaling is enabled, so it would be difficult to use the percentage of traffic going to the canary deployment as a baseline for performance testing. By contrast, setting a weight of, for example, 1 for a backend in the HAProxy config vs. 100 for the other backends guarantees the canary service will always receive 1% of traffic. Of course, 1% of traffic would not be a constant number of req/s over time, but it seems like a more stable value than the alternative.

As far as the original question though, for my own knowledge and for anyone searching for this answer later, does "cross namespace service support" simply mean that one can route to different namespaces in the same config?

Thanks!

from voyager.

@stevenpall , we have added option to set weights to a service using annotation ingress.appscode.com/backend.weight . This will give you more fine grain control over backends of a ingress. All the backends must be in the same namespace.

Cross namespace support will not be added, as that can't be supported without breaking the current. YAML format.

This will be out with 1.5.5 release in next week.

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