Deduplicate RC/RS controller code.

The code was already 99% similar between RC and RS.
This is a wild idea to try to deduplicate the two controllers
in a type-safe manner without adding tons of boilerplate,
and without using code generation.

They are still separate resources. This is a refactor that isn't
intended to change any behavior.

pkg/controller/replication/replication_controller_utils.go

@@ -19,123 +19,10 @@ limitations under the License.
 package replication
 
 import (
-	"fmt"
-	"reflect"
-
-	"github.com/golang/glog"
 	"k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/labels"
-	v1core "k8s.io/client-go/kubernetes/typed/core/v1"
-	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
 )
 
-// updateReplicationControllerStatus attempts to update the Status.Replicas of the given controller, with a single GET/PUT retry.
-func updateReplicationControllerStatus(c v1core.ReplicationControllerInterface, rc v1.ReplicationController, newStatus v1.ReplicationControllerStatus) (*v1.ReplicationController, error) {
-	// This is the steady state. It happens when the rc doesn't have any expectations, since
-	// we do a periodic relist every 30s. If the generations differ but the replicas are
-	// the same, a caller might've resized to the same replica count.
-	if rc.Status.Replicas == newStatus.Replicas &&
-		rc.Status.FullyLabeledReplicas == newStatus.FullyLabeledReplicas &&
-		rc.Status.ReadyReplicas == newStatus.ReadyReplicas &&
-		rc.Status.AvailableReplicas == newStatus.AvailableReplicas &&
-		rc.Generation == rc.Status.ObservedGeneration &&
-		reflect.DeepEqual(rc.Status.Conditions, newStatus.Conditions) {
-		return &rc, nil
-	}
-	// Save the generation number we acted on, otherwise we might wrongfully indicate
-	// that we've seen a spec update when we retry.
-	// TODO: This can clobber an update if we allow multiple agents to write to the
-	// same status.
-	newStatus.ObservedGeneration = rc.Generation
-
-	var getErr, updateErr error
-	var updatedRC *v1.ReplicationController
-	for i, rc := 0, &rc; ; i++ {
-		glog.V(4).Infof(fmt.Sprintf("Updating status for rc: %s/%s, ", rc.Namespace, rc.Name) +
-			fmt.Sprintf("replicas %d->%d (need %d), ", rc.Status.Replicas, newStatus.Replicas, *(rc.Spec.Replicas)) +
-			fmt.Sprintf("fullyLabeledReplicas %d->%d, ", rc.Status.FullyLabeledReplicas, newStatus.FullyLabeledReplicas) +
-			fmt.Sprintf("readyReplicas %d->%d, ", rc.Status.ReadyReplicas, newStatus.ReadyReplicas) +
-			fmt.Sprintf("availableReplicas %d->%d, ", rc.Status.AvailableReplicas, newStatus.AvailableReplicas) +
-			fmt.Sprintf("sequence No: %v->%v", rc.Status.ObservedGeneration, newStatus.ObservedGeneration))
-
-		rc.Status = newStatus
-		updatedRC, updateErr = c.UpdateStatus(rc)
-		if updateErr == nil {
-			return updatedRC, nil
-		}
-		// Stop retrying if we exceed statusUpdateRetries - the replicationController will be requeued with a rate limit.
-		if i >= statusUpdateRetries {
-			break
-		}
-		// Update the controller with the latest resource version for the next poll
-		if rc, getErr = c.Get(rc.Name, metav1.GetOptions{}); getErr != nil {
-			// If the GET fails we can't trust status.Replicas anymore. This error
-			// is bound to be more interesting than the update failure.
-			return nil, getErr
-		}
-	}
-
-	return nil, updateErr
-}
-
-// OverlappingControllers sorts a list of controllers by creation timestamp, using their names as a tie breaker.
-type OverlappingControllers []*v1.ReplicationController
-
-func (o OverlappingControllers) Len() int      { return len(o) }
-func (o OverlappingControllers) Swap(i, j int) { o[i], o[j] = o[j], o[i] }
-
-func (o OverlappingControllers) Less(i, j int) bool {
-	if o[i].CreationTimestamp.Equal(&o[j].CreationTimestamp) {
-		return o[i].Name < o[j].Name
-	}
-	return o[i].CreationTimestamp.Before(&o[j].CreationTimestamp)
-}
-
-func calculateStatus(rc *v1.ReplicationController, filteredPods []*v1.Pod, manageReplicasErr error) v1.ReplicationControllerStatus {
-	newStatus := rc.Status
-	// Count the number of pods that have labels matching the labels of the pod
-	// template of the replication controller, the matching pods may have more
-	// labels than are in the template. Because the label of podTemplateSpec is
-	// a superset of the selector of the replication controller, so the possible
-	// matching pods must be part of the filteredPods.
-	fullyLabeledReplicasCount := 0
-	readyReplicasCount := 0
-	availableReplicasCount := 0
-	templateLabel := labels.Set(rc.Spec.Template.Labels).AsSelectorPreValidated()
-	for _, pod := range filteredPods {
-		if templateLabel.Matches(labels.Set(pod.Labels)) {
-			fullyLabeledReplicasCount++
-		}
-		if podutil.IsPodReady(pod) {
-			readyReplicasCount++
-			if podutil.IsPodAvailable(pod, rc.Spec.MinReadySeconds, metav1.Now()) {
-				availableReplicasCount++
-			}
-		}
-	}
-
-	failureCond := GetCondition(rc.Status, v1.ReplicationControllerReplicaFailure)
-	if manageReplicasErr != nil && failureCond == nil {
-		var reason string
-		if diff := len(filteredPods) - int(*(rc.Spec.Replicas)); diff < 0 {
-			reason = "FailedCreate"
-		} else if diff > 0 {
-			reason = "FailedDelete"
-		}
-		cond := NewReplicationControllerCondition(v1.ReplicationControllerReplicaFailure, v1.ConditionTrue, reason, manageReplicasErr.Error())
-		SetCondition(&newStatus, cond)
-	} else if manageReplicasErr == nil && failureCond != nil {
-		RemoveCondition(&newStatus, v1.ReplicationControllerReplicaFailure)
-	}
-
-	newStatus.Replicas = int32(len(filteredPods))
-	newStatus.FullyLabeledReplicas = int32(fullyLabeledReplicasCount)
-	newStatus.ReadyReplicas = int32(readyReplicasCount)
-	newStatus.AvailableReplicas = int32(availableReplicasCount)
-	return newStatus
-}
-
 // NewReplicationControllerCondition creates a new replication controller condition.
 func NewReplicationControllerCondition(condType v1.ReplicationControllerConditionType, status v1.ConditionStatus, reason, msg string) v1.ReplicationControllerCondition {
 	return v1.ReplicationControllerCondition{