add short summary for docker images

README.md

@@ -5,7 +5,7 @@ Visualizing Docker Data
 This command takes the raw Docker JSON and visualizes it in various ways.
 
 For image information, output can be formatted as
-[Graphviz](http://www.graphviz.org) or as a tree in the terminal.
+[Graphviz](http://www.graphviz.org), as a tree in the terminal, or in a short summary.
 
 For container information, only Graphviz output has been implemented.
 
@@ -23,6 +23,14 @@ Image info is visualized with lines indicating parent images:
 
 ![](sample/images.png "Image")
 
+Or in short form:
+
+```
+nate/mongodb: latest
+redis: latest
+ubuntu: 12.04, precise, 12.10, quantal, 13.04, raring
+```
+
 Or as a tree in the terminal:
 
 ```

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."`
+	Short      bool `short:"s" long:"short" description:"Show short summary of images (repo name and list of tags)."`
 	NoTruncate bool `short:"n" long:"no-trunc" description:"Don't truncate the image IDs."`
 }
 
@@ -49,8 +50,10 @@ func (x *ImagesCommand) Execute(args []string) error {
 		}
 
 		fmt.Printf(jsonToTree(images, startImageArg, imagesCommand.NoTruncate))
+	} else if imagesCommand.Short {
+		fmt.Printf(jsonToShort(images))
 	} else {
-		return fmt.Errorf("Please specify either --dot or --tree")
+		return fmt.Errorf("Please specify either --dot, --tree, or --short")
 	}
 
 	return nil
@@ -193,6 +196,37 @@ func jsonToDot(images *[]Image) string {
 	return buffer.String()
 }
 
+func jsonToShort(images *[]Image) string {
+	var buffer bytes.Buffer
+
+	var byRepo = make(map[string][]string)
+
+	for _, image := range *images {
+		for _, repotag := range image.RepoTags {
+			if repotag != "<none>:<none>" {
+
+				// parse the repo name and tag name out
+				// tag is after the last colon
+				lastColonIndex := strings.LastIndex(repotag, ":")
+				tagname := repotag[lastColonIndex+1:]
+				reponame := repotag[0:lastColonIndex]
+
+				if tags, exists := byRepo[reponame]; exists {
+					byRepo[reponame] = append(tags, tagname)
+				} else {
+					byRepo[reponame] = []string{tagname}
+				}
+			}
+		}
+	}
+
+	for repo, tags := range byRepo {
+		buffer.WriteString(fmt.Sprintf("%s: %s\n", repo, strings.Join(tags, ", ")))
+	}
+
+	return buffer.String()
+}
+
 func init() {
 	parser.AddCommand("images",
 		"Visualize docker images.",

images_test.go

@@ -10,6 +10,11 @@ type DotTest struct {
 	regexps []string
 }
 
+type ShortTest struct {
+	json    string
+	regexps []string
+}
+
 type TreeTest struct {
 	json       string
 	startImage string
@@ -114,6 +119,31 @@ func Test_Tree(t *testing.T) {
 	}
 }
 
+func Test_Short(t *testing.T) {
+	shortJSON := `[ { "VirtualSize": 662553464, "Size": 0, "RepoTags": [ "foo:latest" ], "ParentId": "735f5db5626147582d2ae3f2c87be8e5e697c088574c5faaf8d4d1bccab99470", "Id": "c87be8e5e697c735f5db5626147582d2ae3f2088574c5faaf8d4d1bccab99470", "Created": 1386142123 }, { "VirtualSize": 682553464, "Size": 0, "RepoTags": [ "foo:1.0" ], "ParentId": "4c1208b690c68af3476b437e7bc2bcc460f062bda2094d2d8f21a7e70368d358", "Id": "626147582d2ae3735f5db5f2c87be8e5e697c088574c5faaf8d4d1bccab99470", "Created": 1386142123 }, { "VirtualSize": 712553464, "Size": 0, "RepoTags": [ "foo:2.0" ], "ParentId": "626147582d2ae3735f5db5f2c87be8e5e697c088574c5faaf8d4d1bccab99470", "Id": "574c5faaf8d4d1bccab994626147582d2ae3735f5db5f2c87be8e5e697c08870", "Created": 1386142123 }, { "VirtualSize": 752553464, "Size": 0, "RepoTags": [ "private.repo.com:5000:latest" ], "ParentId": "574c5faaf8d4d1bccab994626147582d2ae3735f5db5f2c87be8e5e697c08870", "Id": "aaf8d4d1bccab994574c5f626147582d2ae3735f5db5f2c87be8e5e697c08870", "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 } ]`
+
+	shortTests := []ShortTest{
+		ShortTest{
+			json: shortJSON,
+			regexps: []string{
+				`(?m)foo: latest, 1.0, 2.0`,
+				`(?m)private.repo.com:5000: latest`,
+			},
+		},
+	}
+
+	for _, shortTest := range shortTests {
+		im, _ := parseImagesJSON([]byte(shortTest.json))
+		result := jsonToShort(im)
+
+		for _, regexp := range compileRegexps(t, shortTest.regexps) {
+			if !regexp.MatchString(result) {
+				t.Fatalf("images short content '%s' did not match regexp '%s'", result, regexp)
+			}
+		}
+	}
+}
+
 func compileRegexps(t *testing.T, regexpStrings []string) []*regexp.Regexp {
 
 	compiledRegexps := []*regexp.Regexp{}