implement --tree

images.go

@@ -21,6 +21,7 @@ type Image struct {
 type ImagesCommand struct {
 	Dot        bool `short:"d" long:"dot" description:"Show image information as Graphviz dot."`
 	Tree       bool `short:"t" long:"tree" description:"Show image information as tree."`
+	NoTruncate bool `short:"n" long:"notrunc" description:"Don't truncate the image IDs."`
 }
 
 var imagesCommand ImagesCommand
@@ -38,12 +39,118 @@ func (x *ImagesCommand) Execute(args []string) error {
 	if imagesCommand.Dot {
 		fmt.Printf(jsonToDot(images))
 	} else if imagesCommand.Tree {
-		fmt.Println("Tree output not implemented yet.")
+
+		var startImageArg = ""
+		if len(args) > 0 {
+			startImageArg = args[0]
+		}
+
+		fmt.Printf(jsonToTree(images, startImageArg, imagesCommand.NoTruncate))
 	}
 
 	return nil
 }
 
+func jsonToTree(images *[]Image, startImageArg string, noTrunc bool) string {
+	var buffer bytes.Buffer
+
+	var startImage Image
+
+	var roots []Image
+	var byParent = make(map[string][]Image)
+	for _, image := range *images {
+		if image.ParentId == "" {
+			roots = append(roots, image)
+		} else {
+			if children, exists := byParent[image.ParentId]; exists {
+				byParent[image.ParentId] = append(children, image)
+			} else {
+				byParent[image.ParentId] = []Image{image}
+			}
+		}
+
+		if startImageArg != "" {
+			if startImageArg == image.Id || startImageArg == truncate(image.Id) {
+				startImage = image
+			}
+
+			for _, repotag := range image.RepoTags {
+				if repotag == startImageArg {
+					startImage = image
+				}
+			}
+		}
+	}
+
+	if startImageArg != "" {
+		WalkTree(&buffer, noTrunc, []Image{startImage}, byParent, "")
+	} else {
+		WalkTree(&buffer, noTrunc, roots, byParent, "")
+	}
+
+	return buffer.String()
+}
+
+func WalkTree(buffer *bytes.Buffer, noTrunc bool, images []Image, byParent map[string][]Image, prefix string) {
+	if len(images) > 1 {
+		length := len(images)
+		for index, image := range images {
+			if index+1 == length {
+				PrintTreeNode(buffer, noTrunc, image, prefix+"└─")
+				if subimages, exists := byParent[image.Id]; exists {
+					WalkTree(buffer, noTrunc, subimages, byParent, prefix+"  ")
+				}
+			} else {
+				PrintTreeNode(buffer, noTrunc, image, prefix+"|─")
+				if subimages, exists := byParent[image.Id]; exists {
+					WalkTree(buffer, noTrunc, subimages, byParent, prefix+"| ")
+				}
+			}
+		}
+	} else {
+		for _, image := range images {
+			PrintTreeNode(buffer, noTrunc, image, prefix+"└─")
+			if subimages, exists := byParent[image.Id]; exists {
+				WalkTree(buffer, noTrunc, subimages, byParent, prefix+"  ")
+			}
+		}
+	}
+}
+
+func PrintTreeNode(buffer *bytes.Buffer, noTrunc bool, image Image, prefix string) {
+	var imageID string
+	if noTrunc {
+		imageID = image.Id
+	} else {
+		imageID = truncate(image.Id)
+	}
+
+	buffer.WriteString(fmt.Sprintf("%s%s Virtual Size: %s", prefix, imageID, humanSize(image.VirtualSize)))
+	if image.RepoTags[0] != "<none>:<none>" {
+		buffer.WriteString(fmt.Sprintf(" Tags: %s\n", strings.Join(image.RepoTags, ", ")))
+	} else {
+		buffer.WriteString(fmt.Sprintf("\n"))
+	}
+}
+
+func humanSize(raw int64) string {
+	sizes := []string{"B", "KB", "MB", "GB", "TB"}
+
+	rawFloat := float64(raw)
+	ind := 0
+
+	for {
+		if rawFloat < 1000 {
+			break
+		} else {
+			rawFloat = rawFloat / 1000
+			ind = ind + 1
+		}
+	}
+
+	return fmt.Sprintf("%.01f %s", rawFloat, sizes[ind])
+}
+
 func truncate(id string) string {
 	return id[0:12]
 }

images_test.go

@@ -5,11 +5,18 @@ import (
 	"testing"
 )
 
-type RunTest struct {
+type DotTest struct {
 	json    string
 	regexps []string
 }
 
+type TreeTest struct {
+	json       string
+	startImage string
+	noTrunc    bool
+	regexps    []string
+}
+
 func Test_BadJSON(t *testing.T) {
 	_, err := parseJSON([]byte(` "VirtualSize": 662553464, "Size": 662553464, "RepoTags": [ "<none>:<none>" ], "ParentId": "", "Id": "4c1208b690c68af3476b437e7bc2bcc460f062bda2094d2d8f21a7e70368d358", "Created": 1386114144 }]`))
 
@@ -25,14 +32,14 @@ func Test_Dot(t *testing.T) {
 	}
 	allRegex := compileRegexps(t, allMatch)
 
-	dotTests := []RunTest{
+	dotTests := []DotTest{
-		RunTest{
+		DotTest{
 			json: `[{ "VirtualSize": 662553464, "Size": 662553464, "RepoTags": [ "<none>:<none>" ], "ParentId": "", "Id": "4c1208b690c68af3476b437e7bc2bcc460f062bda2094d2d8f21a7e70368d358", "Created": 1386114144 }]`,
 			regexps: []string{
 				`base -> "4c1208b690c6"`,
 			},
 		},
-		RunTest{
+		DotTest{
 			json: `[{ "VirtualSize": 662553464, "Size": 0, "RepoTags": [ "foo:latest" ], "ParentId": "735f5db5626147582d2ae3f2c87be8e5e697c088574c5faaf8d4d1bccab99470", "Id": "c87be8e5e697c735f5db5626147582d2ae3f2088574c5faaf8d4d1bccab99470", "Created": 1386142123 },{ "VirtualSize": 662553464, "Size": 0, "RepoTags": [ "<none>:<none>" ], "ParentId": "4c1208b690c68af3476b437e7bc2bcc460f062bda2094d2d8f21a7e70368d358", "Id": "735f5db5626147582d2ae3f2c87be8e5e697c088574c5faaf8d4d1bccab99470", "Created": 1386142123 },{ "VirtualSize": 662553464, "Size": 662553464, "RepoTags": [ "<none>:<none>" ], "ParentId": "", "Id": "4c1208b690c68af3476b437e7bc2bcc460f062bda2094d2d8f21a7e70368d358", "Created": 1386114144 }]`,
 			regexps: []string{
 				`base -> "4c1208b690c6"`,
@@ -60,6 +67,32 @@ func Test_Dot(t *testing.T) {
 	}
 }
 
+func Test_Tree(t *testing.T) {
+	treeTests := []TreeTest{
+		TreeTest{
+			json:       `[{ "VirtualSize": 662553464, "Size": 0, "RepoTags": [ "foo:latest" ], "ParentId": "735f5db5626147582d2ae3f2c87be8e5e697c088574c5faaf8d4d1bccab99470", "Id": "c87be8e5e697c735f5db5626147582d2ae3f2088574c5faaf8d4d1bccab99470", "Created": 1386142123 },{ "VirtualSize": 662553464, "Size": 0, "RepoTags": [ "<none>:<none>" ], "ParentId": "4c1208b690c68af3476b437e7bc2bcc460f062bda2094d2d8f21a7e70368d358", "Id": "735f5db5626147582d2ae3f2c87be8e5e697c088574c5faaf8d4d1bccab99470", "Created": 1386142123 },{ "VirtualSize": 662553464, "Size": 662553464, "RepoTags": [ "<none>:<none>" ], "ParentId": "", "Id": "4c1208b690c68af3476b437e7bc2bcc460f062bda2094d2d8f21a7e70368d358", "Created": 1386114144 }]`,
+			startImage: "",
+			noTrunc:    false,
+			regexps: []string{
+				`(?m)└─4c1208b690c6`,
+				`(?m)  └─735f5db56261`,
+				`(?m)    └─c87be8e5e697`,
+			},
+		},
+	}
+
+	for _, treeTest := range treeTests {
+		im, _ := parseJSON([]byte(treeTest.json))
+		result := jsonToTree(im, treeTest.startImage, treeTest.noTrunc)
+
+		for _, regexp := range compileRegexps(t, treeTest.regexps) {
+			if !regexp.MatchString(result) {
+				t.Fatalf("images tree content '%s' did not match regexp '%s'", result, regexp)
+			}
+		}
+	}
+}
+
 func compileRegexps(t *testing.T, regexpStrings []string) []*regexp.Regexp {
 
 	compiledRegexps := []*regexp.Regexp{}