Anthos Service Mesh (ASM) is installed and configured across all agones clusters and the game services cluster. This allows cross cluster communication between services in the mesh. To add a service to the mesh, a sidecar container can be injected into any pod containing the istio.io/rev: asm-managed label. This label can be seen as a patch to the agones-allocator pod as part of the agones deployment manifest. The mesh is used to establish communication between the open-match director and agones allocator.
In addition to cross-cluster communication, the mesh is configured to route requests to the regional agones allocator endpoints based on request header from the open match director. To make a client request from the global game services GKE cluster to one of the regional endpoints, you would ensure:
- That the sidecar is injected appropriately by applying the
istio.io/rev: asm-managedlabel to the pod - Make a request with a
regionheader having a value matching the region of the target cluster. The following is a request made from a pod on the global game services GKE cluster:
curl agones-allocator.agones-system:8000/gameserverallocation -X POST -H "region: asia-east1"
Note: Requests without the
regionheader are redirected to a faulty endpoint and will error out. This is to avoid accidental load balancing between the regional endpoints.