Golang Graph.EdgeBetween方法代码示例

// addImageStreamsToGraph adds all the streams to the graph. The most recent n
// image revisions for a tag will be preserved, where n is specified by the
// algorithm's tagRevisionsToKeep. Image revisions older than n are candidates
// for pruning.  if the image stream's age is at least as old as the minimum
// threshold in algorithm.  Otherwise, if the image stream is younger than the
// threshold, all image revisions for that stream are ineligible for pruning.
//
// addImageStreamsToGraph also adds references from each stream to all the
// layers it references (via each image a stream references).
func addImageStreamsToGraph(g graph.Graph, streams *imageapi.ImageStreamList, algorithm pruneAlgorithm) {
	for i := range streams.Items {
		stream := &streams.Items[i]

		glog.V(4).Infof("Examining ImageStream %s/%s", stream.Namespace, stream.Name)

		// use a weak reference for old image revisions by default
		oldImageRevisionReferenceKind := graph.WeakReferencedImageGraphEdgeKind

		age := util.Now().Sub(stream.CreationTimestamp.Time)
		if age < algorithm.keepYoungerThan {
			// stream's age is below threshold - use a strong reference for old image revisions instead
			glog.V(4).Infof("Stream %s/%s is below age threshold - none of its images are eligible for pruning", stream.Namespace, stream.Name)
			oldImageRevisionReferenceKind = graph.ReferencedImageGraphEdgeKind
		}

		glog.V(4).Infof("Adding ImageStream %s/%s to graph", stream.Namespace, stream.Name)
		isNode := graph.ImageStream(g, stream)
		imageStreamNode := isNode.(*graph.ImageStreamNode)

		for tag, history := range stream.Status.Tags {
			for i := range history.Items {
				n := graph.FindImage(g, history.Items[i].Image)
				if n == nil {
					glog.V(1).Infof("Unable to find image %q in graph (from tag=%q, revision=%d, dockerImageReference=%s)", history.Items[i].Image, tag, i, history.Items[i].DockerImageReference)
					continue
				}
				imageNode := n.(*graph.ImageNode)

				var kind int
				switch {
				case i < algorithm.tagRevisionsToKeep:
					kind = graph.ReferencedImageGraphEdgeKind
				default:
					kind = oldImageRevisionReferenceKind
				}

				glog.V(4).Infof("Checking for existing strong reference from stream %s/%s to image %s", stream.Namespace, stream.Name, imageNode.Image.Name)
				if edge := g.EdgeBetween(imageStreamNode, imageNode); edge != nil && g.EdgeKind(edge) == graph.ReferencedImageGraphEdgeKind {
					glog.V(4).Infof("Strong reference found")
					continue
				}

				glog.V(4).Infof("Adding edge (kind=%d) from %q to %q", kind, imageStreamNode.UniqueName.UniqueName(), imageNode.UniqueName.UniqueName())
				g.AddEdge(imageStreamNode, imageNode, kind)

				glog.V(4).Infof("Adding stream->layer references")
				// add stream -> layer references so we can prune them later
				for _, s := range g.Successors(imageNode) {
					if g.Kind(s) != graph.ImageLayerGraphKind {
						continue
					}
					glog.V(4).Infof("Adding reference from stream %q to layer %q", stream.Name, s.(*graph.ImageLayerNode).Layer)
					g.AddEdge(imageStreamNode, s, graph.ReferencedImageLayerGraphEdgeKind)
				}
			}
		}
	}
}

func findBuildInputs(g osgraph.Graph, n graph.Node, covered osgraph.NodeSet) (base ImageTagLocation, source SourceLocation, err error) {
	// find inputs to the build
	for _, input := range g.Neighbors(n) {
		switch g.EdgeKind(g.EdgeBetween(n, input)) {
		case buildedges.BuildInputEdgeKind:
			if source != nil {
				// report this as an error (unexpected duplicate source)
			}
			covered.Add(input.ID())
			source = input.(SourceLocation)
		case buildedges.BuildInputImageEdgeKind:
			if base != nil {
				// report this as an error (unexpected duplicate input build)
			}
			covered.Add(input.ID())
			base = input.(ImageTagLocation)
		}
	}
	return
}

// DescendentNodesByNodeKind starts at the root navigates down the root.  Every edge is checked against the edgeChecker
// to determine whether or not to follow it.  The nodes at the tail end of every chased edge are then checked against the
// the targetNodeKind.  Matches are added to the return and every checked node then has its edges checked: lather, rinse, repeat
func DescendentNodesByNodeKind(g osgraph.Graph, visitedNodes graphview.IntSet, node graph.Node, targetNodeKind string, edgeChecker osgraph.EdgeFunc) []graph.Node {
	if visitedNodes.Has(node.ID()) {
		return []graph.Node{}
	}
	visitedNodes.Insert(node.ID())

	ret := []graph.Node{}
	for _, successor := range g.Successors(node) {
		edge := g.EdgeBetween(node, successor)

		if edgeChecker(osgraph.New(), node, successor, g.EdgeKinds(edge)) {
			if g.Kind(successor) == targetNodeKind {
				ret = append(ret, successor)
			}

			ret = append(ret, DescendentNodesByNodeKind(g, visitedNodes, successor, targetNodeKind, edgeChecker)...)
		}
	}

	return ret
}

// ImagePipelineFromNode attempts to locate a build flow from the provided node. If no such
// build flow can be located, false is returned.
func ImagePipelineFromNode(g osgraph.Graph, n graph.Node, covered osgraph.NodeSet) (ImagePipeline, bool) {
	flow := ImagePipeline{}
	switch node := n.(type) {

	case *buildgraph.BuildConfigNode:
		covered.Add(n.ID())
		base, src, _ := findBuildInputs(g, n, covered)
		flow.Build = node
		flow.BaseImage = base
		flow.Source = src
		return flow, true

	case ImageTagLocation:
		covered.Add(n.ID())
		flow.Image = node
		for _, input := range g.Neighbors(n) {
			switch g.EdgeKind(g.EdgeBetween(n, input)) {
			case buildedges.BuildOutputEdgeKind:
				covered.Add(input.ID())
				build := input.(*buildgraph.BuildConfigNode)
				if flow.Build != nil {
					// report this as an error (unexpected duplicate input build)
				}
				if build.BuildConfig == nil {
					// report this as as a missing build / broken link
					break
				}
				base, src, _ := findBuildInputs(g, input, covered)
				flow.Build = build
				flow.BaseImage = base
				flow.Source = src
			}
		}
		return flow, true

	default:
		return flow, false
	}
}

// DeploymentPipelines returns a map of DeploymentConfigs to the deployment flows that create them,
// extracted from the provided Graph.
func DeploymentPipelines(g osgraph.Graph) (DeploymentPipelineMap, osgraph.NodeSet) {
	covered := make(osgraph.NodeSet)
	g = g.EdgeSubgraph(osgraph.ReverseGraphEdge)
	flows := make(DeploymentPipelineMap)
	for _, node := range g.NodeList() {
		switch t := node.(type) {
		case *deploygraph.DeploymentConfigNode:
			covered.Add(t.ID())
			images := []ImagePipeline{}
			for _, n := range g.Neighbors(node) {
				// find incoming image edges only
				switch g.EdgeKind(g.EdgeBetween(node, n)) {
				case deployedges.TriggersDeploymentEdgeKind, deployedges.UsedInDeploymentEdgeKind:
					if flow, ok := ImagePipelineFromNode(g, n, covered); ok {
						images = append(images, flow)
					}
				}
			}

			output := []ImagePipeline{}

			// ensure the list of images is ordered the same as what is in the template
			if template := t.DeploymentConfig.Template.ControllerTemplate.Template; template != nil {
				deployedges.EachTemplateImage(
					&template.Spec,
					deployedges.DeploymentConfigHasTrigger(t.DeploymentConfig),
					func(image deployedges.TemplateImage, err error) {
						if err != nil {
							return
						}
						for i := range images {
							switch t := images[i].Image.(type) {
							case *imagegraph.ImageStreamTagNode:
								if image.Ref != nil {
									continue
								}
								from := image.From
								if t.ImageStream.Name != from.Name || t.ImageStream.Namespace != from.Namespace {
									continue
								}
								output = append(output, images[i])
								return
							case *imagegraph.DockerImageRepositoryNode:
								if image.From != nil {
									continue
								}
								ref1, ref2 := t.Ref.Minimal(), image.Ref.DockerClientDefaults().Minimal()
								if ref1 != ref2 {
									continue
								}
								output = append(output, images[i])
								return
							}
						}
					},
				)
			}
			flows[t] = output
		}
	}
	return flows, covered
}

// ServiceAndDeploymentGroups breaks the provided graph of API relationships into ServiceGroup objects,
// ordered consistently. Groups are organized so that overlapping Services and DeploymentConfigs are
// part of the same group, Deployment Configs are each in their own group, and then BuildConfigs are
// part of the last service group.
func ServiceAndDeploymentGroups(g osgraph.Graph) []ServiceGroup {
	deploys, covered := DeploymentPipelines(g)
	other := g.Subgraph(UncoveredDeploymentFlowNodes(covered), UncoveredDeploymentFlowEdges(covered))
	components := search.Tarjan(other)

	serviceGroups := []ServiceGroup{}
	for _, c := range components {
		group := ServiceGroup{}

		matches := osgraph.NodesByKind(other, c, kubegraph.ServiceNodeKind, deploygraph.DeploymentConfigNodeKind)
		svcs, dcs, _ := matches[0], matches[1], matches[2]

		for _, n := range svcs {
			coveredDCs := []*deploygraph.DeploymentConfigNode{}
			coveredRCs := []*kubegraph.ReplicationControllerNode{}
			coveredPods := []*kubegraph.PodNode{}
			for _, neighbor := range other.Neighbors(n) {
				switch other.EdgeKind(g.EdgeBetween(neighbor, n)) {
				case kubeedges.ExposedThroughServiceEdgeKind:
					containerNode := osgraph.GetTopLevelContainerNode(g, neighbor)
					switch castCoveredNode := containerNode.(type) {
					case *deploygraph.DeploymentConfigNode:
						coveredDCs = append(coveredDCs, castCoveredNode)
					case *kubegraph.ReplicationControllerNode:
						coveredRCs = append(coveredRCs, castCoveredNode)
					case *kubegraph.PodNode:
						coveredPods = append(coveredPods, castCoveredNode)
					}
				}
			}
			group.Services = append(group.Services, ServiceReference{
				Service:     n.(*kubegraph.ServiceNode),
				CoveredDCs:  coveredDCs,
				CoveredRCs:  coveredRCs,
				CoveredPods: coveredPods,
			})
		}
		sort.Sort(SortedServiceReferences(group.Services))

		for _, n := range dcs {
			d := n.(*deploygraph.DeploymentConfigNode)
			group.Deployments = append(group.Deployments, DeploymentFlow{
				Deployment: d,
				Images:     deploys[d],
			})
		}
		sort.Sort(SortedDeploymentPipelines(group.Deployments))

		if len(dcs) == 0 || len(svcs) == 0 {
			unknown := g.SubgraphWithNodes(c, osgraph.ExistingDirectEdge)
			for _, n := range unknown.NodeList() {
				g.PredecessorEdges(n, osgraph.AddGraphEdgesTo(unknown), buildedges.BuildOutputEdgeKind)
			}
			unknown = unknown.EdgeSubgraph(osgraph.ReverseGraphEdge)
			for _, n := range unknown.RootNodes() {
				if flow, ok := ImagePipelineFromNode(unknown, n, make(osgraph.NodeSet)); ok {
					group.Builds = append(group.Builds, flow)
				}
			}
		}
		sort.Sort(SortedImagePipelines(group.Builds))

		serviceGroups = append(serviceGroups, group)
	}
	sort.Sort(SortedServiceGroups(serviceGroups))
	return serviceGroups
}

// edgeKind returns true if the edge from "from" to "to" is of the desired kind.
func edgeKind(g graph.Graph, from, to gonum.Node, desiredKind int) bool {
	edge := g.EdgeBetween(from, to)
	kind := g.EdgeKind(edge)
	return kind == desiredKind
}