[Feature] Make head serviceType optional

[kevin85421]

Why are these changes needed?

Minimal configuration for RayCluster CRs should be as simple as possible. This PR makes serviceType optional and the default is ClusterIP.

(from Kubernetes official documentation)

ClusterIP: Exposes the Service on a cluster-internal IP. Choosing this value makes the Service only reachable from within the cluster. This is the default that is used if you don't explicitly specify a type for a Service.

Related issue number

Part of #368

Checks

• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • This PR is not tested :(

Test Helm chart

# Build docker image and install KubeRay operator

# Install RayCluster chart (path: helm-chart/ray-cluster)
helm install raycluster .

kubectl get svc
# NAME                          TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                                         AGE
# kuberay-operator              ClusterIP   10.96.148.109   <none>        8080/TCP                                        3h57m
# kubernetes                    ClusterIP   10.96.0.1       <none>        443/TCP                                         3h59m
# raycluster-kuberay-head-svc   ClusterIP   10.96.88.220    <none>        10001/TCP,6379/TCP,8265/TCP,8080/TCP,8000/TCP   5s

• TYPE of raycluster-kuberay-head-svc is ClusterIP.

[kevin85421]

I currently remove all serviceType from sample YAML files. We can choose some YAML files to write comments about the field serviceType. @DmitriGekhtman do you have any suggestion about which YAML files to keep the comments on? Thank you!

[DmitriGekhtman]

I currently remove all serviceType from sample YAML files. We can choose some YAML files to write comments about the field serviceType. @DmitriGekhtman do you have any suggestion about which YAML files to keep the comments on? Thank you!

raycluster.complete.yaml and raycluster.complete.large.yaml

[Jeffwan]

Seems all reference have been removed. Actually this is optional but not deprecated at this moment. Let's leave some example for customization if user need them

[Jeffwan]

/lgtm

[rentom]

Following Getting Started and the KubeRay-operator was deployed just fine, but

$ kubectl apply -f ray-cluster.autoscaler.yaml
The RayCluster "raycluster-autoscaler" is invalid: spec.headGroupSpec.serviceType: Required value

[kevin85421]

Following Getting Started and the KubeRay-operator was deployed just fine, but

$ kubectl apply -f ray-cluster.autoscaler.yaml
The RayCluster "raycluster-autoscaler" is invalid: spec.headGroupSpec.serviceType: Required value

Oh, the current configuration is only compatible with the latest KubeRay image (i.e. nightly). The document deploys KubeRay operator with the image v0.3.0. Hence, serviceType is a required value. I will open a PR to add serviceType back to sample configurations to keep backward compatibility. Thank @rentom for pointing this out!

[DmitriGekhtman]

Following Getting Started and the KubeRay-operator was deployed just fine, but

$ kubectl apply -f ray-cluster.autoscaler.yaml

The RayCluster "raycluster-autoscaler" is invalid: spec.headGroupSpec.serviceType: Required value

Oh, the current configuration is only compatible with the latest KubeRay image (i.e. nightly). The document deploys KubeRay operator with the image v0.3.0. Hence, serviceType is a required value. I will open a PR to add serviceType back to sample configurations to keep backward compatibility. Thank @rentom for pointing this out!

Could you instead pin the KubeRay configs to the latest KubeRay release, rather than master?

[kevin85421]

Could you instead pin the KubeRay configs to the latest KubeRay release, rather than master?

Open issue #857 to track this. We need to promise that the nightly and latest release KubeRay operator will work well with current sample YAML files.

[DmitriGekhtman]

We need to promise that the nightly and latest release KubeRay operator will work well with current sample YAML files.

Makes sense!
But also when possible we should pin commits, images, etc. in the docs so that nothing suddenly breaks.