docs: add comments describing newly added functions

Signed-off-by: vadasambar <surajrbanakar@gmail.com>

cluster-autoscaler/utils/test/test_utils.go

@@ -59,6 +59,7 @@ func basePod(name string) *apiv1.Pod {
 	return pod
 }
 
+// WithCPU adds requests.cpu (unit: number of CPUs) to all containers in the pod
 func WithCPU(cpu int64) func(*apiv1.Pod) {
 	return func(pod *apiv1.Pod) {
 
@@ -68,6 +69,7 @@ func WithCPU(cpu int64) func(*apiv1.Pod) {
 	}
 }
 
+// WithMilliCPU adds requests.cpu (unit: number of milli CPUs) to all containers in the pod
 func WithMilliCPU(cpu int64) func(*apiv1.Pod) {
 	return func(pod *apiv1.Pod) {
 
@@ -77,6 +79,7 @@ func WithMilliCPU(cpu int64) func(*apiv1.Pod) {
 	}
 }
 
+// WithMemory adds requests.memory to all the containers in the pod
 func WithMemory(mem int64) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
@@ -87,6 +90,8 @@ func WithMemory(mem int64) func(*apiv1.Pod) {
 	}
 }
 
+// WithGPU adds requests.nvidia.com/gpu and limits.nvidia.com/gpu
+// to all the containers in the pod
 func WithGPU(gpusCount int64) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
@@ -98,13 +103,16 @@ func WithGPU(gpusCount int64) func(*apiv1.Pod) {
 	}
 }
 
+// WithGPUToleration adds nvidia.com/gpu:Exists toleration to the pod
 func WithGPUToleration() func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
 		pod.Spec.Tolerations = append(pod.Spec.Tolerations, apiv1.Toleration{Key: resourceNvidiaGPU, Operator: apiv1.TolerationOpExists})
 	}
 }
 
+// WithAnnotations adds annotations to the pods
+// note: if a key already exists, it will be overwritten
 func WithAnnotations(anns map[string]string) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
@@ -115,13 +123,15 @@ func WithAnnotations(anns map[string]string) func(*apiv1.Pod) {
 	}
 }
 
+// WithOwnerRef adds owner ref to pod
 func WithOwnerRef(ownerRefs []metav1.OwnerReference) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
 		pod.OwnerReferences = append(pod.OwnerReferences, ownerRefs...)
 	}
 }
 
+// WithEphemeralStorage adds requests.ephemeral-storage to all the containers in the pod
 func WithEphemeralStorage(ephemeralStorage int64) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
@@ -131,41 +141,47 @@ func WithEphemeralStorage(ephemeralStorage int64) func(*apiv1.Pod) {
 	}
 }
 
+// ScheduledOnNode sets pod's spec.nodeName
 func ScheduledOnNode(nodeName string) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
 		pod.Spec.NodeName = nodeName
 	}
 }
 
+// WithStaticPodAnnotation adds 'kubernetes.io/config.source: file' annotation to the pod
 func WithStaticPodAnnotation() func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
 		pod.Annotations[kube_types.ConfigSourceAnnotationKey] = kube_types.FileSource
 	}
 }
 
+// AsDaemonSetPod adds daemonset owner ref to the pod
 func AsDaemonSetPod(uid string) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
 		pod.OwnerReferences = GenerateOwnerReferences("ds", "DaemonSet", "apps/v1", types.UID(uid))
 	}
 }
 
+// AsReplicaSetPod adds replicaset owner ref to the pod
 func AsReplicaSetPod(uid string, rsName string) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
 		pod.OwnerReferences = GenerateOwnerReferences(rsName, "ReplicaSet", "extensions/v1beta1", types.UID(uid))
 	}
 }
 
+// WithMirrorPodAnnotation adds 'kubernetes.io/config.mirror: mirror' annotation to the pod
 func WithMirrorPodAnnotation(uid string) func(*apiv1.Pod) {
 
 	return func(pod *apiv1.Pod) {
 		pod.ObjectMeta.Annotations[kube_types.ConfigMirrorAnnotationKey] = "mirror"
 	}
 }
 
+// NewTestPod creates pod with options passed as functions
 func NewTestPod(name string, options ...func(*apiv1.Pod)) *apiv1.Pod {
 	pod := basePod(name)