Zone Ingress

To implement cross-zone communication when Kuma is deployed in a multi-zone mode, there is a new proxy type ZoneIngress. These proxies are not attached to any particular workload. Instead, they are bound to that particular zone. Zone Ingress can proxy the traffic between all meshes, so we need only one deployment for every zone.
All requests that are sent from one zone to another will be directed to the proper instance by the Zone Ingress.

The ZoneIngress entity includes a few sections:

  • type: must be ZoneIngress.
  • name: this is the name of the Zone Ingress instance, and it must be unique for any given zone.
  • networking: contains networking parameters of the Zone Ingress
    • address: the address of the network interface Zone Ingress is listening on. Could be the address of either public or private network interface, but the latter must be used with a load balancer.
    • port: is a port that Zone Ingress is listening on default to 10001
    • advertisedAddress: an IP address or hostname which will be used to communicate with the Zone Ingress. Zone Ingress doesn’t listen on this address. If Zone Ingress is exposed using a load balancer, then the address of the load balancer should be used here. If Zone Ingress is listening on the public network interface, then the address of the public network interface should be used here.
    • advertisedPort: a port which will be used to communicate with the Zone Ingress. Zone Ingress doesn’t listen on this port.
    • admin: determines parameters related to Envoy Admin API
      • port: the port that Envoy Admin API will listen to
  • availableServices [auto-generated on Kuma CP] : the list of services that could be consumed through the Zone Ingress
  • zone [auto-generated on Kuma CP] : zone where Zone Ingress belongs to

Zone Ingress without advertisedAddress and advertisedPort is not taken into account when generating Envoy configuration, because they cannot be accessed by data plane proxies from other zones.

The recommended way to deploy a ZoneIngress proxy in Kubernetes is to use kumactl, or the Helm charts as specified in multi-zone. It works as a separate deployment of a single-container pod.

Kuma will try to resolve advertisedAddress and advertisedPort automatically by checking the Service associated with this Zone Ingress.

If the Service type is Load Balancer, Kuma will wait for public IP to be resolved. It may take a couple of minutes to receive public IP depending on the LB implementation of your Kubernetes provider.

If the Service type is Node Port, Kuma will take an External IP of the first Node in the cluster and combine it with Node Port.

You can provide your own public address and port using the following annotations on the Ingress deployment

  • kuma.io/ingress-public-address
  • kuma.io/ingress-public-port

A ZoneIngress deployment can be scaled horizontally. Many instances can have the same advertised address and advertised port because they can be put behind one load balancer.

Last Updated: 11/4/2022, 19:20:08 PM