chore(helm): mark GPU node as no CPU resource available (#474)

Because

- In current setup, GPU node has CPU resources available, causing pure
CPU model will sometime be scheduled onto GPU node, which is not
desirable, we want CPU models to only be scheduled on CPU node.

This commit

- mark GPU node as no CPU resource available for scheduling

charts/core/templates/ray-service/ray-service.yaml

@@ -114,6 +114,9 @@ spec:
       maxReplicas: {{ $workerGroupSpecs.maxReplicas }}
       groupName: {{ $workerGroupSpecs.groupName }}
       rayStartParams:
+        {{- if $workerGroupSpecs.gpuWorkerGroup.enabled }}
+        num-cpus: "0"
+        {{- end }}
         {{- if $workerGroupSpecs.gpuWorkerGroup.customResource }}
         resources: {{ $workerGroupSpecs.gpuWorkerGroup.customResource }}
         {{- end }}

charts/core/values.yaml

@@ -687,11 +687,11 @@ rayService:
   headGroupSpec:
     resources:
       limits:
-        cpu: "0"
+        cpu: "2"
         memory: "4Gi"
         nvidia.com/gpu: 0
       requests:
-        cpu: "0"
+        cpu: "2"
         memory: "4Gi"
         nvidia.com/gpu: 0
     affinity: {}