pkg/image/controller/scheduler: Restore some logging

pkg/image/controller/scheduler.go

@@ -5,6 +5,7 @@ import (
 
 	utilwait "k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/util/flowcontrol"
+	"k8s.io/klog"
 )
 
 // NOTE: scheduler's semantics do not lend it for reuse elsewhere and its use in
@@ -33,7 +34,6 @@ type bucket map[interface{}]interface{}
 // newScheduler creates a scheduler with bucketCount buckets, a rate limiter for restricting
 // the rate at which buckets are processed, and a function to invoke when items are scanned in
 // a bucket.
-// TODO: remove DEBUG statements from this file once this logic has been adequately validated.
 func newScheduler(bucketCount int, bucketLimiter flowcontrol.RateLimiter, fn func(key, value interface{})) *scheduler {
 	// Add one more bucket to serve as the "current" bucket
 	bucketCount++
@@ -58,9 +58,11 @@ func (s *scheduler) RunUntil(ch <-chan struct{}) {
 func (s *scheduler) RunOnce() {
 	key, value, last := s.next()
 	if last {
+		klog.V(5).Infof("Image controller scheduler: waiting for limit")
 		s.limiter.Accept()
 		return
 	}
+	klog.V(5).Infof("Image controller scheduler: handle %s", key)
 	s.handle(key, value)
 }
 
@@ -74,6 +76,7 @@ func (s *scheduler) at(inc int) int {
 func (s *scheduler) next() (interface{}, interface{}, bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	klog.V(5).Infof("Image controller scheduler: queue (%d):\n %#v", s.position, s.buckets)
 
 	last := s.buckets[s.position]
 	// Grab the first item in the bucket, move it to the end and return it.
@@ -84,6 +87,7 @@ func (s *scheduler) next() (interface{}, interface{}, bool) {
 	}
 	// The bucket was empty.  Advance to the next bucket.
 	s.position = s.at(1)
+	klog.V(5).Infof("Image controller scheduler: bucket was empty, advance to %d of %d buckets", s.position, len(s.buckets))
 	return nil, nil, true
 }
 
@@ -116,6 +120,7 @@ func (s *scheduler) Add(key, value interface{}) {
 			least = size
 		}
 	}
+	klog.V(5).Infof("Image controller scheduler: add %s to bucket %d", key, target)
 	s.buckets[target][key] = value
 }
 
@@ -126,13 +131,14 @@ func (s *scheduler) Remove(key, value interface{}) bool {
 	defer s.mu.Unlock()
 
 	match := true
-	for _, bucket := range s.buckets {
+	for i, bucket := range s.buckets {
 		if value != nil {
 			if old, ok := bucket[key]; ok && old != value {
 				match = false
 				continue
 			}
 		}
+		klog.V(5).Infof("Image controller scheduler: remove %s from bucket %d", key, i)
 		delete(bucket, key)
 	}
 	return match