From a4b3b9ffbb9bf4cac1863ac8c3b5dbf7748f9fdd Mon Sep 17 00:00:00 2001 From: Kunal Kushwaha Date: Mon, 15 Oct 2018 10:40:30 +0900 Subject: Tree implementation for podman images Signed-off-by: Kunal Kushwaha --- cmd/podman/cliconfig/config.go | 5 ++ cmd/podman/image.go | 1 + cmd/podman/tree.go | 190 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 196 insertions(+) create mode 100644 cmd/podman/tree.go (limited to 'cmd') diff --git a/cmd/podman/cliconfig/config.go b/cmd/podman/cliconfig/config.go index ec08eedb5..cb9d9a338 100644 --- a/cmd/podman/cliconfig/config.go +++ b/cmd/podman/cliconfig/config.go @@ -66,6 +66,11 @@ type TagValues struct { PodmanCommand } +type TreeValues struct { + PodmanCommand + WhatRequires bool +} + type WaitValues struct { PodmanCommand Interval uint diff --git a/cmd/podman/image.go b/cmd/podman/image.go index 52bac6ecb..fb295b8a1 100644 --- a/cmd/podman/image.go +++ b/cmd/podman/image.go @@ -60,6 +60,7 @@ var imageSubCommands = []*cobra.Command{ _rmSubCommand, _saveCommand, _tagCommand, + _treeCommand, } func init() { diff --git a/cmd/podman/tree.go b/cmd/podman/tree.go new file mode 100644 index 000000000..ebda18cdb --- /dev/null +++ b/cmd/podman/tree.go @@ -0,0 +1,190 @@ +package main + +import ( + "context" + "fmt" + + "github.com/containers/libpod/cmd/podman/cliconfig" + "github.com/containers/libpod/cmd/podman/libpodruntime" + "github.com/containers/libpod/libpod/image" + units "github.com/docker/go-units" + "github.com/pkg/errors" + "github.com/spf13/cobra" +) + +const ( + middleItem = "├── " + continueItem = "│ " + lastItem = "└── " +) + +var ( + treeCommand cliconfig.TreeValues + + treeDescription = "Prints layer hierarchy of an image in a tree format" + _treeCommand = &cobra.Command{ + Use: "tree", + Short: treeDescription, + Long: treeDescription, + RunE: func(cmd *cobra.Command, args []string) error { + treeCommand.InputArgs = args + treeCommand.GlobalFlags = MainGlobalOpts + return treeCmd(&treeCommand) + }, + Example: "podman image tree alpine:latest", + } +) + +func init() { + treeCommand.Command = _treeCommand + treeCommand.SetUsageTemplate(UsageTemplate()) + treeCommand.Flags().BoolVar(&treeCommand.WhatRequires, "whatrequires", false, "Show all child images and layers of the specified image") +} + +// infoImage keep information of Image along with all associated layers +type infoImage struct { + // id of image + id string + // tags of image + tags []string + // layers stores all layers of image. + layers []image.LayerInfo +} + +func treeCmd(c *cliconfig.TreeValues) error { + args := c.InputArgs + if len(args) == 0 { + return errors.Errorf("an image name must be specified") + } + if len(args) > 1 { + return errors.Errorf("you must provide at most 1 argument") + } + + runtime, err := libpodruntime.GetRuntime(&c.PodmanCommand) + if err != nil { + return errors.Wrapf(err, "error creating libpod runtime") + } + defer runtime.Shutdown(false) + + img, err := runtime.ImageRuntime().NewFromLocal(args[0]) + if err != nil { + return err + } + + // Fetch map of image-layers, which is used for printing output. + layerInfoMap, err := image.GetLayersMapWithImageInfo(runtime.ImageRuntime()) + if err != nil { + return errors.Wrapf(err, "error while retriving layers of image %q", img.InputName) + } + + // Create an imageInfo and fill the image and layer info + imageInfo := &infoImage{ + id: img.ID(), + tags: img.Names(), + } + + size, err := img.Size(context.Background()) + if err != nil { + return errors.Wrapf(err, "error while retriving image size") + } + fmt.Printf("Image ID: %s\n", imageInfo.id[:12]) + fmt.Printf("Tags:\t %s\n", imageInfo.tags) + fmt.Printf("Size:\t %v\n", units.HumanSizeWithPrecision(float64(*size), 4)) + fmt.Printf(fmt.Sprintf("Image Layers\n")) + + if !c.WhatRequires { + // fill imageInfo with layers associated with image. + // the layers will be filled such that + // (Start)RootLayer->...intermediate Parent Layer(s)-> TopLayer(End) + err := buildImageHierarchyMap(imageInfo, layerInfoMap, img.TopLayer()) + if err != nil { + return err + } + // Build output from imageInfo into buffer + printImageHierarchy(imageInfo) + + } else { + // fill imageInfo with layers associated with image. + // the layers will be filled such that + // (Start)TopLayer->...intermediate Child Layer(s)-> Child TopLayer(End) + // (Forks)... intermediate Child Layer(s) -> Child Top Layer(End) + err := printImageChildren(layerInfoMap, img.TopLayer(), "", true) + if err != nil { + return err + } + } + + return nil +} + +// Stores hierarchy of images such that all parent layers using which image is built are stored in imageInfo +// Layers are added such that (Start)RootLayer->...intermediate Parent Layer(s)-> TopLayer(End) +func buildImageHierarchyMap(imageInfo *infoImage, layerMap map[string]*image.LayerInfo, layerID string) error { + if layerID == "" { + return nil + } + ll, ok := layerMap[layerID] + if !ok { + return fmt.Errorf("lookup error: layerid %s not found", layerID) + } + if err := buildImageHierarchyMap(imageInfo, layerMap, ll.ParentID); err != nil { + return err + } + + imageInfo.layers = append(imageInfo.layers, *ll) + return nil +} + +// Stores all children layers which are created using given Image. +// Layers are stored as follows +// (Start)TopLayer->...intermediate Child Layer(s)-> Child TopLayer(End) +// (Forks)... intermediate Child Layer(s) -> Child Top Layer(End) +func printImageChildren(layerMap map[string]*image.LayerInfo, layerID string, prefix string, last bool) error { + if layerID == "" { + return nil + } + ll, ok := layerMap[layerID] + if !ok { + return fmt.Errorf("lookup error: layerid %s, not found", layerID) + } + fmt.Printf(prefix) + + //initialize intend with middleItem to reduce middleItem checks. + intend := middleItem + if !last { + // add continueItem i.e. '|' for next iteration prefix + prefix = prefix + continueItem + } else if len(ll.ChildID) > 1 || len(ll.ChildID) == 0 { + // The above condition ensure, alignment happens for node, which has more then 1 childern. + // If node is last in printing hierarchy, it should not be printed as middleItem i.e. ├── + intend = lastItem + prefix = prefix + " " + } + + var tags string + if len(ll.RepoTags) > 0 { + tags = fmt.Sprintf(" Top Layer of: %s", ll.RepoTags) + } + fmt.Printf("%sID: %s Size: %7v%s\n", intend, ll.ID[:12], units.HumanSizeWithPrecision(float64(ll.Size), 4), tags) + for count, childID := range ll.ChildID { + if err := printImageChildren(layerMap, childID, prefix, (count == len(ll.ChildID)-1)); err != nil { + return err + } + } + return nil +} + +// prints the layers info of image +func printImageHierarchy(imageInfo *infoImage) { + for count, l := range imageInfo.layers { + var tags string + intend := middleItem + if len(l.RepoTags) > 0 { + tags = fmt.Sprintf(" Top Layer of: %s", l.RepoTags) + } + if count == len(imageInfo.layers)-1 { + intend = lastItem + } + fmt.Printf("%s ID: %s Size: %7v%s\n", intend, l.ID[:12], units.HumanSizeWithPrecision(float64(l.Size), 4), tags) + } +} -- cgit v1.2.3-54-g00ecf