handling image stream changes

Signed-off-by: Michal Minář <[email protected]>

Author: Michal Minář

pkg/oc/admin/prune/imageprune/helper.go

@@ -7,18 +7,18 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/docker/distribution/registry/api/errcode"
+	"github.com/golang/glog"
+
 	kmeta "k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime"
+	kerrors "k8s.io/apimachinery/pkg/util/errors"
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
 	kapiref "k8s.io/kubernetes/pkg/api/ref"
 	kapi "k8s.io/kubernetes/pkg/apis/core"
 
-	"github.com/docker/distribution/registry/api/errcode"
-	"github.com/golang/glog"
-
-	kerrors "k8s.io/apimachinery/pkg/util/errors"
-
 	imageapi "github.com/openshift/origin/pkg/image/apis/image"
+	imagegraph "github.com/openshift/origin/pkg/oc/graph/imagegraph/nodes"
 	"github.com/openshift/origin/pkg/util/netutils"
 )
 
@@ -302,3 +302,32 @@ func getRef(obj runtime.Object) *kapi.ObjectReference {
 	}
 	return ref
 }
+
+// removeImageNodesAtIndexes removes nodes at the given indexes from the given array and returns the resulting
+// slice that points to the original array. The indexes must be valid and sorted in ascending order. Otherwise
+// the result is undefined.
+func removeImageNodesAtIndexes(nodes []*imagegraph.ImageNode, indexes ...int) []*imagegraph.ImageNode {
+	if len(nodes) == 0 || len(indexes) == 0 {
+		return nodes
+	}
+
+	tmp := nodes[:indexes[0]]
+
+	highestIndex := -1
+
+	for i, n := range indexes {
+		if n <= highestIndex || n >= len(nodes) || n < 0 {
+			// indexes are not sorted or invalid
+			break
+		}
+
+		highestIndex = n
+
+		if i < len(indexes)-1 && indexes[i+1] < len(nodes) && indexes[i+1] > highestIndex {
+			tmp = append(tmp, nodes[n+1:indexes[i+1]]...)
+		} else {
+			tmp = append(tmp, nodes[n+1:]...)
+		}
+	}
+	return tmp
+}

pkg/oc/admin/prune/imageprune/helper_test.go

@@ -11,6 +11,8 @@ import (
 
 	"k8s.io/apimachinery/pkg/util/diff"
 	knet "k8s.io/apimachinery/pkg/util/net"
+
+	imagegraph "github.com/openshift/origin/pkg/oc/graph/imagegraph/nodes"
 )
 
 type requestStats struct {
@@ -215,3 +217,92 @@ func TestDefaultImagePinger(t *testing.T) {
 		}()
 	}
 }
+
+func TestRemoveImageNodesAtIndexes(t *testing.T) {
+	for _, tc := range []struct {
+		name                     string
+		nodes                    int
+		remove                   []int
+		expectedRemainingIndexes []int
+	}{
+		{
+			name:   "no nodes",
+			remove: []int{0, 1, 2},
+			expectedRemainingIndexes: []int{},
+		},
+		{
+			name:   "nothing to remove",
+			nodes:  4,
+			remove: []int{},
+			expectedRemainingIndexes: []int{0, 1, 2, 3},
+		},
+		{
+			name:   "remove first",
+			nodes:  3,
+			remove: []int{0},
+			expectedRemainingIndexes: []int{1, 2},
+		},
+		{
+			name:   "remove last",
+			nodes:  3,
+			remove: []int{2},
+			expectedRemainingIndexes: []int{0, 1},
+		},
+		{
+			name:   "remove 2 consecutive",
+			nodes:  4,
+			remove: []int{1, 2},
+			expectedRemainingIndexes: []int{0, 3},
+		},
+		{
+			name:   "remove odd",
+			nodes:  5,
+			remove: []int{1, 3, 5, 7},
+			expectedRemainingIndexes: []int{0, 2, 4},
+		},
+		{
+			name:   "remove even",
+			nodes:  5,
+			remove: []int{0, 2, 4, 6, 8},
+			expectedRemainingIndexes: []int{1, 3},
+		},
+		{
+			name:   "unsorted sequence",
+			nodes:  5,
+			remove: []int{0, 2, 2, 2, 4, 3, 2, 1, 2},
+			expectedRemainingIndexes: []int{1, 3, 4},
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			// generate nodes
+			nodes := make([]*imagegraph.ImageNode, 0, tc.nodes)
+			nodeIndexes := map[*imagegraph.ImageNode]int{}
+			for i := 0; i < tc.nodes; i++ {
+				node := &imagegraph.ImageNode{}
+				nodes = append(nodes, node)
+				nodeIndexes[nodes[i]] = i
+			}
+
+			nodes = removeImageNodesAtIndexes(nodes, tc.remove...)
+
+			for i := 0; i < len(nodes) || i < len(tc.expectedRemainingIndexes); i++ {
+				if i >= len(nodes) {
+					t.Errorf("no nodes at index %d where node #%d is expected", i, tc.expectedRemainingIndexes[i])
+					continue
+				}
+				newIndex, ok := nodeIndexes[nodes[i]]
+				if !ok {
+					t.Errorf("unknown node present on index %d", i)
+					continue
+				}
+				if i >= len(tc.expectedRemainingIndexes) {
+					t.Errorf("found node #%d at index %d where no node is expected", newIndex, i)
+					continue
+				}
+				if a, e := newIndex, tc.expectedRemainingIndexes[i]; a != e {
+					t.Errorf("expected node #%d at index %d, not node #%d", e, i, a)
+				}
+			}
+		})
+	}
+}

pkg/oc/admin/prune/imageprune/prune.go

@@ -22,6 +22,7 @@ import (
 	kerrors "k8s.io/apimachinery/pkg/util/errors"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/client-go/util/retry"
 	kapi "k8s.io/kubernetes/pkg/apis/core"
 	kapisext "k8s.io/kubernetes/pkg/apis/extensions"
@@ -60,7 +61,7 @@ const (
 	// ImageNode to an ImageComponentNode.
 	ReferencedImageManifestEdgeKind = "ReferencedImageManifest"
 
-	pruneImageWorkerCount = 5
+	defaultPruneImageWorkerCount = 5
 )
 
 // RegistryClientFactoryFunc is a factory function returning a registry client for use in a worker.
@@ -149,6 +150,8 @@ type PrunerOptions struct {
 	// Streams is the entire list of image streams across all namespaces in the
 	// cluster.
 	Streams *imageapi.ImageStreamList
+	// StreamsWatcher watches for stream changes.
+	StreamsWatcher watch.Interface
 	// Pods is the entire list of pods across all namespaces in the cluster.
 	Pods *kapi.PodList
 	// RCs is the entire list of replication controllers across all namespaces in
@@ -176,6 +179,9 @@ type PrunerOptions struct {
 	RegistryClientFactory RegistryClientFactoryFunc
 	// RegistryURL is the URL of the integrated Docker registry.
 	RegistryURL *url.URL
+	// NumWorkers is a desired number of workers concurrently handling image prune jobs. If less than 1, the
+	// default number of workers will be spawned.
+	NumWorkers int
 }
 
 // Pruner knows how to prune istags, images, manifest, layers, image configs and blobs.
@@ -199,10 +205,13 @@ type pruner struct {
 	algorithm             pruneAlgorithm
 	registryClientFactory RegistryClientFactoryFunc
 	registryURL           *url.URL
+	imageStreamWatcher    watch.Interface
+	imageStreamLimits     map[string][]*kapi.LimitRange
 	// sorted queue of images to prune
 	queue []*imagegraph.ImageNode
 	// contains prunable images removed from queue that are currently being processed
 	processedImages map[*imagegraph.ImageNode]*Job
+	numWorkers      int
 }
 
 var _ Pruner = &pruner{}
@@ -283,6 +292,13 @@ func NewPruner(options PrunerOptions) (Pruner, kerrors.Aggregate) {
 		registryClientFactory: options.RegistryClientFactory,
 		registryURL:           options.RegistryURL,
 		processedImages:       make(map[*imagegraph.ImageNode]*Job),
+		imageStreamWatcher:    options.StreamsWatcher,
+		imageStreamLimits:     options.LimitRanges,
+		numWorkers:            options.NumWorkers,
+	}
+
+	if p.numWorkers < 1 {
+		p.numWorkers = defaultPruneImageWorkerCount
 	}
 
 	if err := p.buildGraph(options); err != nil {
@@ -776,6 +792,50 @@ func (p *pruner) addBuildStrategyImageReferencesToGraph(referrer *kapi.ObjectRef
 	return nil
 }
 
+func (p *pruner) handleImageStreamEvent(event watch.Event) {
+	getIsNode := func() (*imageapi.ImageStream, *imagegraph.ImageStreamNode) {
+		is, ok := event.Object.(*imageapi.ImageStream)
+		if !ok {
+			utilruntime.HandleError(fmt.Errorf("internal error: expected ImageStream object in %s event, not %T", event.Type, event.Object))
+			return nil, nil
+		}
+		n := p.g.Find(imagegraph.ImageStreamNodeName(is))
+		if isNode, ok := n.(*imagegraph.ImageStreamNode); ok {
+			return is, isNode
+		}
+		return is, nil
+	}
+
+	switch event.Type {
+	case watch.Added:
+		is, isNode := getIsNode()
+		if is == nil {
+			return
+		}
+		if isNode != nil {
+			glog.V(4).Infof("Ignoring added ImageStream %s that is already present in the graph", getName(is))
+			return
+		}
+		glog.V(4).Infof("Adding ImageStream %s to the graph", getName(is))
+		p.addImageStreamsToGraph(&imageapi.ImageStreamList{Items: []imageapi.ImageStream{*is}}, p.imageStreamLimits)
+
+	case watch.Modified:
+		is, isNode := getIsNode()
+		if is == nil {
+			return
+		}
+
+		if isNode != nil {
+			glog.V(4).Infof("Removing updated ImageStream %s from the graph", getName(is))
+			// first remove the current node if present
+			p.g.RemoveNode(imagegraph.EnsureImageStreamNode(p.g, is))
+		}
+
+		glog.V(4).Infof("Adding updated ImageStream %s back to the graph", getName(is))
+		p.addImageStreamsToGraph(&imageapi.ImageStreamList{Items: []imageapi.ImageStream{*is}}, p.imageStreamLimits)
+	}
+}
+
 // getImageNodes returns only nodes of type ImageNode.
 func getImageNodes(nodes []gonum.Node) map[string]*imagegraph.ImageNode {
 	ret := make(map[string]*imagegraph.ImageNode)
@@ -1112,7 +1172,7 @@ func (p *pruner) Prune(
 
 	defer close(jobChan)
 
-	for i := 0; i < pruneImageWorkerCount; i++ {
+	for i := 0; i < p.numWorkers; i++ {
 		worker, err := NewWorker(
 			p.algorithm,
 			p.registryClientFactory,
@@ -1145,9 +1205,10 @@ func (p *pruner) runLoop(
 	jobChan chan<- *Job,
 	resultChan <-chan JobResult,
 ) (deletions []Deletion, failures []Failure) {
+	isUpdateChan := p.imageStreamWatcher.ResultChan()
 	for {
 		// make workers busy
-		for len(p.processedImages) < pruneImageWorkerCount {
+		for len(p.processedImages) < p.numWorkers {
 			job, blocked := p.getNextJob()
 			if blocked {
 				break
@@ -1172,7 +1233,8 @@ func (p *pruner) runLoop(
 				failures = append(failures, failure)
 			}
 			delete(p.processedImages, res.Job.Image)
-			// TODO: handle image stream updates
+		case event := <-isUpdateChan:
+			p.handleImageStreamEvent(event)
 			// TODO: handle new images - do not add them to the queue though
 		}
 	}
@@ -1220,13 +1282,8 @@ func (p *pruner) getNextJob() (job *Job, blocked bool) {
 	blocked = job == nil
 
 	// remove no longer prunable images from the queue
-	for i, n := range toRemove {
-		if i < len(toRemove)-1 {
-			p.queue = append(p.queue[:n-i], p.queue[n+1-i:toRemove[i+1]-i]...)
-		} else {
-			p.queue = append(p.queue[:n-i], p.queue[n+1-i:]...)
-		}
-	}
+	// TODO: highly ineffective for a long queue O(N*M), consider the use of doubly linked list
+	p.queue = removeImageNodesAtIndexes(p.queue, toRemove...)
 
 	return
 }