feat: allow specifying runtime class in runner spec (#580)

This allows using the `runtimeClassName` directive in the runner's spec.

One of the use-cases for this is Kata Containers, which use `runtimeClassName` in a pod spec as an indicator that the pod should run inside a Kata container. This allows us a greater degree of pod isolation.

api/v1alpha1/runner_types.go

@@ -107,6 +107,11 @@ type RunnerSpec struct {
 	HostAliases []corev1.HostAlias `json:"hostAliases,omitempty"`
 	// +optional
 	VolumeSizeLimit *resource.Quantity `json:"volumeSizeLimit,omitempty"`
+
+	// RuntimeClassName is the container runtime configuration that containers should run under.
+	// More info: https://kubernetes.io/docs/concepts/containers/runtime-class
+	// +optional
+	RuntimeClassName *string `json:"runtimeClassName,omitempty"`
 }
 
 // ValidateRepository validates repository field.

api/v1alpha1/zz_generated.deepcopy.go

@@ -791,6 +791,11 @@ func (in *RunnerSpec) DeepCopyInto(out *RunnerSpec) {
 		x := (*in).DeepCopy()
 		*out = &x
 	}
+	if in.RuntimeClassName != nil {
+		in, out := &in.RuntimeClassName, &out.RuntimeClassName
+		*out = new(string)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSpec.