Allocator Service

To allocate a game server, Agones provides a gRPC and REST service with mTLS authentication, called agones-allocator that can be used instead of GameServerAllocations .

Both services are accessible through a Kubernetes service that is externalized using a load balancer and they run on the same port. For requests to succeed, a client certificate must be provided that is in the authorization list of the allocator service. The remainder of this article describes how to manually make a successful allocation request using the API.

The guide assumes you have command line tools installed for jq, go and openssl.

GameServerAllocation vs Allocator Service

There are several reasons you may prefer to use the Allocator Service over the GameServerAllocation custom resource definition, depending on your architecture and requirements:

• A requirement to do multi-cluster allocation.
• Want to create Allocations from outside the Agones Kubernetes cluster.
• Prefer SSL based authentication over Kubernetes RBAC.
• Prefer a gRPC or REST based API over an integration with the Kubernetes API.

Find the external IP

The service is hosted under the same namespace as the Agones controller. To find the external IP of your allocator service, replace agones-system namespace with the namespace to which Agones is deployed and execute the following command:

kubectl get service agones-allocator -n agones-system

The output of the command should look like:

NAME                        TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)            AGE
agones-allocator            LoadBalancer   10.55.251.73    34.82.195.204   443:30250/TCP      7d22h

Server TLS certificate

If the agones-allocator service is installed as a LoadBalancer using a reserved IP, a valid self-signed server TLS certificate is generated using the IP provided. Otherwise, the server TLS certificate should be replaced. If you installed Agones using helm, you can easily reconfigure the allocator service with a preset IP address by setting the agones.allocator.http.loadBalancerIP parameter to the address that was automatically assigned to the service and helm upgrade:

EXTERNAL_IP=$(kubectl get services agones-allocator -n agones-system -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
helm upgrade --install --wait \
   --set agones.allocator.http.loadBalancerIP=${EXTERNAL_IP} \
   ...