从 Kubernetes 集群内部进行 Canary 流量管理

Question

I'm trying to achieve canary-style traffic management for applications which are not yet part of the Istio service-mesh but still are in the same k8s cluster. For example:

Pod A in the namespace non-mesh calls Service B in namespace mesh which is bound to the pods inside the service mesh. A desired state would be when traffic to these pods is distributed by the rules described in related VirtualService object.

Is this possible by Istio's native facilities?

Answer 1

In Istio a VirtualService Objects inserts a Route rule inside the service mesh sidecars. These routes rules are evaluated on the client-side (In your case that would be the sidecar associated with Service A if there was a sidecar present with it). Due to this, you can't perform traffic management between Service A to Service B ( As there is no client sidecar). One possible method to solve this, in case you don't want to enable mesh for the entire non-mesh namespace is to only insert sidecars for Service A . This will create all the necessary rules in the sidecar and then you can use traffic weights to modify requests between Service A and Service B