Refactor image tree for API usage

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

12 files changed, 254 insertions, 171 deletions

diff --git a/API.md b/API.md
index cfbe394de..2460de09f 100644
--- a/API.md
+++ b/API.md
@@ -95,6 +95,8 @@ in the [API.md](https://github.com/containers/libpod/blob/master/API.md) file in
 
 [func ImageSave(options: ImageSaveOptions) MoreResponse](#ImageSave)
 
+[func ImageTree(name: string, whatRequires: bool) string](#ImageTree)
+
 [func ImagesPrune(all: bool, filter: []string) []string](#ImagesPrune)
 
 [func ImportImage(source: string, reference: string, message: string, changes: []string, delete: bool) string](#ImportImage)
@@ -775,6 +777,18 @@ $ varlink call -m unix:/run/podman/io.podman/io.podman.ImageExists '{"name": "im
 
 method ImageSave(options: [ImageSaveOptions](#ImageSaveOptions)) [MoreResponse](#MoreResponse)</div>
 ImageSave allows you to save an image from the local image storage to a tarball
+### <a name="ImageTree"></a>func ImageTree
+<div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
+
+method ImageTree(name: [string](https://godoc.org/builtin#string), whatRequires: [bool](https://godoc.org/builtin#bool)) [string](https://godoc.org/builtin#string)</div>
+ImageTree returns the image tree for the provided image name or ID
+#### Example
+~~~
+$ varlink call -m unix:/run/podman/io.podman/io.podman.ImageTree '{"name": "alpine"}'
+{
+  "tree":  "Image ID: e7d92cdc71fe\nTags:     [docker.io/library/alpine:latest]\nSize:     5.861MB\nImage Layers\n└──  ID: 5216338b40a7 Size: 5.857MB Top Layer of: [docker.io/library/alpine:latest]\n"
+}
+~~~
 ### <a name="ImagesPrune"></a>func ImagesPrune
 <div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
 
diff --git a/cmd/podman/tree.go b/cmd/podman/tree.go
index 69b42639d..28c770f0c 100644
--- a/cmd/podman/tree.go
+++ b/cmd/podman/tree.go
@@ -1,23 +1,14 @@
 package main
 
 import (
-	"context"
 	"fmt"
 
 	"github.com/containers/libpod/cmd/podman/cliconfig"
-	"github.com/containers/libpod/libpod/image"
 	"github.com/containers/libpod/pkg/adapter"
-	"github.com/docker/go-units"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 )
 
-const (
-	middleItem   = "├── "
-	continueItem = "│   "
-	lastItem     = "└── "
-)
-
 var (
 	treeCommand cliconfig.TreeValues
 
@@ -56,95 +47,11 @@ func treeCmd(c *cliconfig.TreeValues) error {
 		return errors.Wrapf(err, "error creating libpod runtime")
 	}
 	defer runtime.DeferredShutdown(false)
-	imageInfo, layerInfoMap, img, err := runtime.Tree(c.InputArgs[0])
-	if err != nil {
-		return err
-	}
-	return printTree(imageInfo, layerInfoMap, img, c.WhatRequires)
-}
 
-func printTree(imageInfo *image.InfoImage, layerInfoMap map[string]*image.LayerInfo, img *adapter.ContainerImage, whatRequires bool) error {
-	size, err := img.Size(context.Background())
+	tree, err := runtime.ImageTree(c.InputArgs[0], c.WhatRequires)
 	if err != nil {
 		return err
 	}
-
-	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))
-	if img.TopLayer() != "" {
-		fmt.Printf("Image Layers\n")
-	} else {
-		fmt.Printf("No Image Layers\n")
-	}
-
-	if !whatRequires {
-		// fill imageInfo with layers associated with image.
-		// the layers will be filled such that
-		// (Start)RootLayer->...intermediate Parent Layer(s)-> TopLayer(End)
-		// 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)
-		return printImageChildren(layerInfoMap, img.TopLayer(), "", true)
-	}
-	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.Print(prefix)
-
-	//initialize intend with middleItem to reduce middleItem checks.
-	intend := middleItem
-	if !last {
-		// add continueItem i.e. '|' for next iteration 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 children.
-		// If node is last in printing hierarchy, it should not be printed as middleItem i.e. ├──
-		intend = lastItem
-		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
-		}
-	}
+	fmt.Print(tree)
 	return nil
 }
-
-// prints the layers info of image
-func printImageHierarchy(imageInfo *image.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)
-	}
-}
diff --git a/cmd/podman/varlink/io.podman.varlink b/cmd/podman/varlink/io.podman.varlink
index a0227c48c..e9792fa8f 100644
--- a/cmd/podman/varlink/io.podman.varlink
+++ b/cmd/podman/varlink/io.podman.varlink
@@ -1188,6 +1188,16 @@ method GetPodsByStatus(statuses: []string) -> (pods: []string)
 # ~~~
 method ImageExists(name: string) -> (exists: int)
 
+# ImageTree returns the image tree for the provided image name or ID
+# #### Example
+# ~~~
+# $ varlink call -m unix:/run/podman/io.podman/io.podman.ImageTree '{"name": "alpine"}'
+# {
+#   "tree":  "Image ID: e7d92cdc71fe\nTags:     [docker.io/library/alpine:latest]\nSize:     5.861MB\nImage Layers\n└──  ID: 5216338b40a7 Size: 5.857MB Top Layer of: [docker.io/library/alpine:latest]\n"
+# }
+# ~~~
+method ImageTree(name: string, whatRequires: bool) -> (tree: string)
+
 # ContainerExists takes a full or partial container ID or name and returns an int as to
 # whether the container exists in local storage.  A result of 0 means the container does
 # exists; whereas a result of 1 means it could not be found.
diff --git a/libpod/image/tree.go b/libpod/image/tree.go
new file mode 100644
index 000000000..c7c69462f
--- /dev/null
+++ b/libpod/image/tree.go
@@ -0,0 +1,138 @@
+package image
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/docker/go-units"
+	"github.com/pkg/errors"
+)
+
+const (
+	middleItem   = "├── "
+	continueItem = "│   "
+	lastItem     = "└── "
+)
+
+type tree struct {
+	img       *Image
+	imageInfo *InfoImage
+	layerInfo map[string]*LayerInfo
+	sb        *strings.Builder
+}
+
+// GenerateTree creates an image tree string representation for displaying it
+// to the user.
+func (i *Image) GenerateTree(whatRequires bool) (string, error) {
+	// Fetch map of image-layers, which is used for printing output.
+	layerInfo, err := GetLayersMapWithImageInfo(i.imageruntime)
+	if err != nil {
+		return "", errors.Wrapf(err, "error while retrieving layers of image %q", i.InputName)
+	}
+
+	// Create an imageInfo and fill the image and layer info
+	imageInfo := &InfoImage{
+		ID:   i.ID(),
+		Tags: i.Names(),
+	}
+
+	if err := BuildImageHierarchyMap(imageInfo, layerInfo, i.TopLayer()); err != nil {
+		return "", err
+	}
+	sb := &strings.Builder{}
+	tree := &tree{i, imageInfo, layerInfo, sb}
+	if err := tree.print(whatRequires); err != nil {
+		return "", err
+	}
+	return tree.string(), nil
+}
+
+func (t *tree) string() string {
+	return t.sb.String()
+}
+
+func (t *tree) print(whatRequires bool) error {
+	size, err := t.img.Size(context.Background())
+	if err != nil {
+		return err
+	}
+
+	fmt.Fprintf(t.sb, "Image ID: %s\n", t.imageInfo.ID[:12])
+	fmt.Fprintf(t.sb, "Tags:     %s\n", t.imageInfo.Tags)
+	fmt.Fprintf(t.sb, "Size:     %v\n", units.HumanSizeWithPrecision(float64(*size), 4))
+	if t.img.TopLayer() != "" {
+		fmt.Fprintf(t.sb, "Image Layers\n")
+	} else {
+		fmt.Fprintf(t.sb, "No Image Layers\n")
+	}
+
+	if !whatRequires {
+		// fill imageInfo with layers associated with image.
+		// the layers will be filled such that
+		// (Start)RootLayer->...intermediate Parent Layer(s)-> TopLayer(End)
+		// Build output from imageInfo into buffer
+		t.printImageHierarchy(t.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)
+		return t.printImageChildren(t.layerInfo, t.img.TopLayer(), "", true)
+	}
+	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 (t *tree) printImageChildren(layerMap map[string]*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.Fprint(t.sb, prefix)
+
+	//initialize intend with middleItem to reduce middleItem checks.
+	intend := middleItem
+	if !last {
+		// add continueItem i.e. '|' for next iteration 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 children.
+		// If node is last in printing hierarchy, it should not be printed as middleItem i.e. ├──
+		intend = lastItem
+		prefix += " "
+	}
+
+	var tags string
+	if len(ll.RepoTags) > 0 {
+		tags = fmt.Sprintf(" Top Layer of: %s", ll.RepoTags)
+	}
+	fmt.Fprintf(t.sb, "%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 := t.printImageChildren(layerMap, childID, prefix, count == len(ll.ChildID)-1); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// prints the layers info of image
+func (t *tree) 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.Fprintf(t.sb, "%s ID: %s Size: %7v%s\n", intend, l.ID[:12], units.HumanSizeWithPrecision(float64(l.Size), 4), tags)
+	}
+}
diff --git a/pkg/adapter/images.go b/pkg/adapter/images.go
deleted file mode 100644
index 762f1a656..000000000
--- a/pkg/adapter/images.go
+++ /dev/null
@@ -1,33 +0,0 @@
-// +build !remoteclient
-
-package adapter
-
-import (
-	"github.com/containers/libpod/libpod/image"
-	"github.com/pkg/errors"
-)
-
-// Tree ...
-func (r *LocalRuntime) Tree(imageOrID string) (*image.InfoImage, map[string]*image.LayerInfo, *ContainerImage, error) {
-	img, err := r.NewImageFromLocal(imageOrID)
-	if err != nil {
-		return nil, nil, nil, err
-	}
-
-	// Fetch map of image-layers, which is used for printing output.
-	layerInfoMap, err := image.GetLayersMapWithImageInfo(r.Runtime.ImageRuntime())
-	if err != nil {
-		return nil, nil, nil, errors.Wrapf(err, "error while retrieving layers of image %q", img.InputName)
-	}
-
-	// Create an imageInfo and fill the image and layer info
-	imageInfo := &image.InfoImage{
-		ID:   img.ID(),
-		Tags: img.Names(),
-	}
-
-	if err := image.BuildImageHierarchyMap(imageInfo, layerInfoMap, img.TopLayer()); err != nil {
-		return nil, nil, nil, err
-	}
-	return imageInfo, layerInfoMap, img, nil
-}
diff --git a/pkg/adapter/images_remote.go b/pkg/adapter/images_remote.go
index 1d4997d9a..e7b38dccc 100644
--- a/pkg/adapter/images_remote.go
+++ b/pkg/adapter/images_remote.go
@@ -7,9 +7,7 @@ import (
 	"encoding/json"
 
 	iopodman "github.com/containers/libpod/cmd/podman/varlink"
-	"github.com/containers/libpod/libpod/image"
 	"github.com/containers/libpod/pkg/inspect"
-	"github.com/pkg/errors"
 )
 
 // Inspect returns returns an ImageData struct from over a varlink connection
@@ -24,32 +22,3 @@ func (i *ContainerImage) Inspect(ctx context.Context) (*inspect.ImageData, error
 	}
 	return &data, nil
 }
-
-// Tree ...
-func (r *LocalRuntime) Tree(imageOrID string) (*image.InfoImage, map[string]*image.LayerInfo, *ContainerImage, error) {
-	layerInfoMap := make(map[string]*image.LayerInfo)
-	imageInfo := &image.InfoImage{}
-
-	img, err := r.NewImageFromLocal(imageOrID)
-	if err != nil {
-		return nil, nil, nil, err
-	}
-
-	reply, err := iopodman.GetLayersMapWithImageInfo().Call(r.Conn)
-	if err != nil {
-		return nil, nil, nil, errors.Wrap(err, "failed to obtain image layers")
-	}
-	if err := json.Unmarshal([]byte(reply), &layerInfoMap); err != nil {
-		return nil, nil, nil, errors.Wrap(err, "failed to unmarshal image layers")
-	}
-
-	reply, err = iopodman.BuildImageHierarchyMap().Call(r.Conn, imageOrID)
-	if err != nil {
-		return nil, nil, nil, errors.Wrap(err, "failed to get build image map")
-	}
-	if err := json.Unmarshal([]byte(reply), imageInfo); err != nil {
-		return nil, nil, nil, errors.Wrap(err, "failed to unmarshal build image map")
-	}
-
-	return imageInfo, layerInfoMap, img, nil
-}
diff --git a/pkg/adapter/runtime.go b/pkg/adapter/runtime.go
index 40089797d..dfe6b7f07 100644
--- a/pkg/adapter/runtime.go
+++ b/pkg/adapter/runtime.go
@@ -133,6 +133,15 @@ func (r *LocalRuntime) NewImageFromLocal(name string) (*ContainerImage, error) {
 	return &ContainerImage{img}, nil
 }
 
+// ImageTree reutnrs an new image.Tree for the provided `imageOrID` and `whatrequires` flag
+func (r *LocalRuntime) ImageTree(imageOrID string, whatRequires bool) (string, error) {
+	img, err := r.Runtime.ImageRuntime().NewFromLocal(imageOrID)
+	if err != nil {
+		return "", err
+	}
+	return img.GenerateTree(whatRequires)
+}
+
 // LoadFromArchiveReference calls into local storage to load an image from an archive
 func (r *LocalRuntime) LoadFromArchiveReference(ctx context.Context, srcRef types.ImageReference, signaturePolicyPath string, writer io.Writer) ([]*ContainerImage, error) {
 	var containerImages []*ContainerImage
diff --git a/pkg/adapter/runtime_remote.go b/pkg/adapter/runtime_remote.go
index c908358ff..220d4cf75 100644
--- a/pkg/adapter/runtime_remote.go
+++ b/pkg/adapter/runtime_remote.go
@@ -344,6 +344,10 @@ func (r *LocalRuntime) New(ctx context.Context, name, signaturePolicyPath, authf
 	return newImage, nil
 }
 
+func (r *LocalRuntime) ImageTree(imageOrID string, whatRequires bool) (string, error) {
+	return iopodman.ImageTree().Call(r.Conn, imageOrID, whatRequires)
+}
+
 // IsParent goes through the layers in the store and checks if i.TopLayer is
 // the parent of any other layer in store. Double check that image with that
 // layer exists as well.
diff --git a/pkg/api/handlers/libpod/images.go b/pkg/api/handlers/libpod/images.go
index bcbe4977e..eac0e4dad 100644
--- a/pkg/api/handlers/libpod/images.go
+++ b/pkg/api/handlers/libpod/images.go
@@ -46,17 +46,34 @@ func ImageExists(w http.ResponseWriter, r *http.Request) {
 }
 
 func ImageTree(w http.ResponseWriter, r *http.Request) {
-	// tree is a bit of a mess ... logic is in adapter and therefore not callable from here. needs rework
-
-	// name := utils.GetName(r)
-	// _, layerInfoMap, _, err := s.Runtime.Tree(name)
-	// if err != nil {
-	//	Error(w, "Something went wrong.", http.StatusInternalServerError, errors.Wrapf(err, "Failed to find image information for %q", name))
-	//	return
-	// }
-	//	it is not clear to me how to deal with this given all the processing of the image
-	// is in main.  we need to discuss how that really should be and return something useful.
-	handlers.UnsupportedHandler(w, r)
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	name := utils.GetName(r)
+
+	img, err := runtime.ImageRuntime().NewFromLocal(name)
+	if err != nil {
+		utils.Error(w, "Something went wrong.", http.StatusNotFound, errors.Wrapf(err, "Failed to find image %s", name))
+		return
+	}
+
+	decoder := r.Context().Value("decoder").(*schema.Decoder)
+	query := struct {
+		WhatRequires bool `schema:"whatrequires"`
+	}{
+		WhatRequires: false,
+	}
+	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
+			errors.Wrapf(err, "failed to parse parameters for %s", r.URL.String()))
+		return
+	}
+
+	tree, err := img.GenerateTree(query.WhatRequires)
+	if err != nil {
+		utils.Error(w, "Server error", http.StatusInternalServerError, errors.Wrapf(err, "failed to generate image tree for %s", name))
+		return
+	}
+
+	utils.WriteResponse(w, http.StatusOK, tree)
 }
 
 func GetImage(w http.ResponseWriter, r *http.Request) {
@@ -72,8 +89,8 @@ func GetImage(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	utils.WriteResponse(w, http.StatusOK, inspect)
-
 }
+
 func GetImages(w http.ResponseWriter, r *http.Request) {
 	images, err := utils.GetImages(w, r)
 	if err != nil {
diff --git a/pkg/api/handlers/swagger.go b/pkg/api/handlers/swagger.go
index 10525bfc7..4ba123ba9 100644
--- a/pkg/api/handlers/swagger.go
+++ b/pkg/api/handlers/swagger.go
@@ -136,3 +136,12 @@ type swagInspectVolumeResponse struct {
 		libpod.InspectVolumeData
 	}
 }
+
+// Image tree response
+// swagger:response LibpodImageTreeResponse
+type swagImageTreeResponse struct {
+	// in:body
+	Body struct {
+		ImageTreeResponse
+	}
+}
diff --git a/pkg/api/server/register_images.go b/pkg/api/server/register_images.go
index f082c5fec..4706a7c69 100644
--- a/pkg/api/server/register_images.go
+++ b/pkg/api/server/register_images.go
@@ -578,6 +578,31 @@ func (s *APIServer) registerImagesHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: '#/responses/InternalError'
 	r.Handle(VersionedPath("/libpod/images/{name}/exists"), APIHandler(s.Context, libpod.ImageExists))
+	// swagger:operation POST /libpod/images/{name}/tree libpod libpodImageTree
+	// ---
+	// tags:
+	//  - images
+	// summary: Image tree
+	// description: Retrieve the image tree for the provided image name or ID
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the name or ID of the container
+	//  - in: query
+	//    name: whatrequires
+	//    type: boolean
+	//    description: show all child images and layers of the specified image
+	// produces:
+	// - application/json
+	// responses:
+	//   200:
+	//     $ref: '#/responses/LibpodImageTreeResponse'
+	//   401:
+	//     $ref: '#/responses/NoSuchImage'
+	//   500:
+	//     $ref: '#/responses/InternalError'
 	r.Handle(VersionedPath("/libpod/images/{name}/tree"), APIHandler(s.Context, libpod.ImageTree))
 	// swagger:operation GET /libpod/images/{name}/history libpod libpodImageHistory
 	// ---
diff --git a/pkg/varlinkapi/images.go b/pkg/varlinkapi/images.go
index b144bfa5e..c4809f16b 100644
--- a/pkg/varlinkapi/images.go
+++ b/pkg/varlinkapi/images.go
@@ -1016,3 +1016,17 @@ func (i *LibpodAPI) BuildImageHierarchyMap(call iopodman.VarlinkCall, name strin
 	}
 	return call.ReplyBuildImageHierarchyMap(string(b))
 }
+
+// ImageTree returns the image tree string for the provided image name or ID
+func (i *LibpodAPI) ImageTree(call iopodman.VarlinkCall, nameOrID string, whatRequires bool) error {
+	img, err := i.Runtime.ImageRuntime().NewFromLocal(nameOrID)
+	if err != nil {
+		return call.ReplyErrorOccurred(err.Error())
+	}
+
+	tree, err := img.GenerateTree(whatRequires)
+	if err != nil {
+		return call.ReplyErrorOccurred(err.Error())
+	}
+	return call.ReplyImageTree(tree)
+}