v0.0.3 (#3)

* Add `--depth` parameter

Makefile

@@ -1,7 +1,8 @@
-VERSION := 0.0.2
+APP_NAME := docker-tree
+VERSION := 0.0.3
 
 build: test
-	go build -ldflags="-X 'main.version=$(VERSION)'" -o docker-tree ./cmd/
+	go build -ldflags="-X 'main.version=${VERSION}'" -o ${APP_NAME} ./cmd/
 
 test:
 	go vet ./...

README.md

@@ -21,11 +21,7 @@ mv ./docker-tree ~/.docker/cli-plugins/docker-tree
 ```shell
 # Absent image will be pulled automatically
 ➜ docker tree alpine:3.20 /etc/ssl
-3.20: Pulling from library/alpine
-a258b2a6b59a: Pull complete
-Digest: sha256:b89d9c93e9ed3597455c90a0b88a8bbb5cb7188438f70953fede212a0c4394e0
-Status: Downloaded newer image for alpine:3.20
-docker.io/library/alpine:3.20
+processing image: alpine:3.20
 ssl/
 ├── cert.pem
 ├── certs/
@@ -35,17 +31,4 @@ ssl/
 ├── openssl.cnf
 ├── openssl.cnf.dist
 └── private/
-
-# Show file tree with symlinks
-➜ docker tree -l alpine:3.20 | head
-precessing image: alpine:3.20
-/
-├── bin/
-│   ├── arch -> /bin/busybox
-│   ├── ash -> /bin/busybox
-│   ├── base64 -> /bin/busybox
-│   ├── bbconfig -> /bin/busybox
-│   ├── busybox
-│   ├── cat -> /bin/busybox
-│   ├── chattr -> /bin/busybox
 ```

cmd/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"math"
 	"os"
 
 	"github.com/skondrashov/docker-tree/internal/docker"
@@ -22,6 +23,7 @@ func main() {
 			var (
 				quiet     bool
 				showLinks bool
+				depth     int
 			)
 
 			cmd := &cobra.Command{
@@ -47,11 +49,17 @@ You can also specify a directory to see the file tree relative to this directory
 						treeRoot = args[1]
 					}
 
+					depth++ // to display not only "/" with --depth == 1
+					if depth <= 1 {
+						depth = math.MaxInt
+					}
+
 					treeStrings, err := docker.GetImageTree(docker.GetTreeOpts{
 						Cli:       dockerCli,
 						ImageID:   imageID,
 						Quiet:     quiet,
 						ShowLinks: showLinks,
+						Depth:     depth,
 						TreeRoot:  treeRoot,
 					})
 					if err != nil {
@@ -64,6 +72,7 @@ You can also specify a directory to see the file tree relative to this directory
 			}
 
 			flags := cmd.Flags()
+			flags.IntVarP(&depth, "depth", "d", 0, "Show maximum depth of hierarchical trees, 0 - unlimited")
 			flags.BoolVarP(&quiet, "quiet", "q", false, "Suppress verbose output")
 			flags.BoolVarP(&showLinks, "links", "l", false, "Show symlinks destination")
 

internal/docker/layers.go

@@ -118,7 +118,10 @@ func getFileTreeFromLayer(layerReader *tar.Reader) (*fileTreeNode, error) {
 		if err != nil {
 			return nil, errNotATar
 		}
-		fileTree.addChild(header)
+
+		if !strings.HasSuffix(header.Name, whiteoutDirPrefix) {
+			fileTree.addChild(header)
+		}
 	}
 	return fileTree, nil
 }

internal/docker/main.go

@@ -13,6 +13,7 @@ type GetTreeOpts struct {
 	ImageID   string
 	Quiet     bool
 	ShowLinks bool
+	Depth     int
 	TreeRoot  string
 }
 
@@ -36,7 +37,7 @@ func GetImageTree(opts GetTreeOpts) (string, error) {
 	}
 
 	if !opts.Quiet {
-		fmt.Fprintf(opts.Cli.Out(), "precessing image: %s\n", opts.ImageID)
+		fmt.Fprintf(opts.Cli.Out(), "processing image: %s\n", opts.ImageID)
 	}
 
 	imageReader, err := opts.Cli.Client().ImageSave(ctx, []string{opts.ImageID})
@@ -64,5 +65,10 @@ func GetImageTree(opts GetTreeOpts) (string, error) {
 		return "", fmt.Errorf("there is no such path in the image: %s", opts.TreeRoot)
 	}
 
-	return node.getString("", opts.ShowLinks, true, true), nil
+	printOptions := getStringOpts{
+		showLinks: opts.ShowLinks,
+		depth:     opts.Depth,
+	}
+
+	return node.getString("", printOptions, true, true), nil
 }

internal/docker/tree.go

@@ -15,7 +15,8 @@ const (
 	last   = "└── "
 	link   = " -> "
 
-	delFilePrefix = ".wh."
+	whiteoutFilePrefix = ".wh."
+	whiteoutDirPrefix  = ".wh..wh..opq"
 )
 
 type fileTreeNode struct {
@@ -25,7 +26,17 @@ type fileTreeNode struct {
 	Children []*fileTreeNode
 }
 
-func (n *fileTreeNode) getString(prefix string, showLinks, isFirst, isLast bool) string {
+type getStringOpts struct {
+	showLinks bool
+	depth     int
+}
+
+func (n *fileTreeNode) getString(prefix string, opts getStringOpts, isFirst, isLast bool) string {
+	opts.depth--
+	if opts.depth == -1 {
+		return empty
+	}
+
 	passPrefix := prefix
 	currentPrefix := empty
 
@@ -45,12 +56,12 @@ func (n *fileTreeNode) getString(prefix string, showLinks, isFirst, isLast bool)
 	}
 
 	result := fmt.Sprintf("%s%s%s\n", prefix, currentPrefix, name)
-	if showLinks && n.Symlink != "" {
+	if opts.showLinks && n.Symlink != "" {
 		result = fmt.Sprintf("%s%s%s%s%s\n", prefix, currentPrefix, name, link, n.Symlink)
 	}
 
 	for i, child := range n.Children {
-		result += child.getString(passPrefix, showLinks, false, i == len(n.Children)-1)
+		result += child.getString(passPrefix, opts, false, i == len(n.Children)-1)
 	}
 
 	return result
@@ -127,8 +138,8 @@ func mergeFileTrees(original, updated *fileTreeNode) (*fileTreeNode, error) {
 			continue
 		}
 
-		if strings.HasPrefix(updatedChild.Name, delFilePrefix) {
-			updatedChild.Name = strings.TrimPrefix(updatedChild.Name, delFilePrefix)
+		if strings.HasPrefix(updatedChild.Name, whiteoutFilePrefix) {
+			updatedChild.Name = strings.TrimPrefix(updatedChild.Name, whiteoutFilePrefix)
 			if err := original.deleteNode(updatedChild); err != nil {
 				return nil, fmt.Errorf("error deleting file %s: %w", updatedChild.Name, err)
 			}

internal/docker/tree_test.go

@@ -20,28 +20,45 @@ func Test_fileTreeNode_String(t *testing.T) {
 	tests := []struct {
 		name   string
 		fields fields
+		opts   getStringOpts
 		want   string
 	}{
 		{
 			name:   "get string of only root node",
 			fields: fields{"/", true, nil},
+			opts:   getStringOpts{showLinks: false, depth: 99999},
 			want:   "/\n",
 		},
 		{
 			name:   "get string of /etc/file",
 			fields: fields{"/", true, []*fileTreeNode{&etcNode}},
+			opts:   getStringOpts{showLinks: false, depth: 99999},
 			want:   "/\n└── etc/\n    └── file\n",
 		},
 		{
 			name:   "get string of /etc/file + /other_file",
 			fields: fields{"/", true, []*fileTreeNode{&etcNode, &otherFileNode}},
+			opts:   getStringOpts{showLinks: false, depth: 99999},
 			want:   "/\n├── etc/\n│   └── file\n└── other_file\n",
 		},
 		{
 			name:   "get string with symlink",
 			fields: fields{"/", true, []*fileTreeNode{&etcNode, &binNodeWithSymlink}},
+			opts:   getStringOpts{showLinks: true, depth: 99999},
 			want:   "/\n├── etc/\n│   └── file\n└── bin/\n    ├── file\n    └── link -> /tmp/file\n",
 		},
+		{
+			name:   "get string with depth = 1",
+			fields: fields{"/", true, []*fileTreeNode{&etcNode, &binNodeWithSymlink}},
+			opts:   getStringOpts{showLinks: false, depth: 2}, // we use depth == 2 because we want it to handle root + one more level of nesting
+			want:   "/\n├── etc/\n└── bin/\n",
+		},
+		{
+			name:   "get string with depth = 2",
+			fields: fields{"/", true, []*fileTreeNode{&etcNode, &binNodeWithSymlink}},
+			opts:   getStringOpts{showLinks: false, depth: 3},
+			want:   "/\n├── etc/\n│   └── file\n└── bin/\n    ├── file\n    └── link\n",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -50,28 +67,15 @@ func Test_fileTreeNode_String(t *testing.T) {
 				IsDir:    tt.fields.IsDir,
 				Children: tt.fields.Children,
 			}
-			if got := n.getString("", true, true, true); got != tt.want {
+
+			if got := n.getString("", tt.opts, true, true); got != tt.want {
 				t.Errorf("getString() = %v, want %v", got, tt.want)
 			}
 		})
 	}
 }
 
 func Test_mergeFileTrees(t *testing.T) {
-	singleFileTree := &fileTreeNode{"file", "", false, nil}
-
-	etcWithFile := &fileTreeNode{"etc", "", true, []*fileTreeNode{singleFileTree}}
-	rootWithEtcTreeNode := &fileTreeNode{"/", "", true, []*fileTreeNode{etcWithFile}}
-
-	varWithFile := &fileTreeNode{"var", "", true, []*fileTreeNode{singleFileTree}}
-	rootWithVarTreeNode := &fileTreeNode{"/", "", true, []*fileTreeNode{varWithFile}}
-
-	deleteSingleFileTree := &fileTreeNode{".wh.file", "", false, nil}
-	etcWithDeleteFile := &fileTreeNode{"etc", "", true, []*fileTreeNode{deleteSingleFileTree}}
-	rootWithEtcWithDeleteFileTreeNode := &fileTreeNode{"/", "", true, []*fileTreeNode{etcWithDeleteFile}}
-
-	rootWithEtcWithDeleteFileAndAddVarFileTreeNode := &fileTreeNode{"/", "", true, []*fileTreeNode{etcWithDeleteFile, varWithFile}}
-
 	type args struct {
 		original *fileTreeNode
 		updated  *fileTreeNode
@@ -86,40 +90,83 @@ func Test_mergeFileTrees(t *testing.T) {
 			name: "original is nil",
 			args: args{
 				original: nil,
-				updated:  singleFileTree,
+				updated:  &fileTreeNode{"file", "", false, nil},
 			},
-			want:    singleFileTree,
+			want:    &fileTreeNode{"file", "", false, nil},
 			wantErr: false,
 		},
 		{
 			name: "add /var/file to /etc/file",
 			args: args{
-				original: rootWithEtcTreeNode,
-				updated:  rootWithVarTreeNode,
+				original: &fileTreeNode{"/", "", true, []*fileTreeNode{
+					{"etc", "", true, []*fileTreeNode{
+						{"file", "", false, nil},
+					}},
+				}},
+				updated: &fileTreeNode{"/", "", true, []*fileTreeNode{
+					{"var", "", true, []*fileTreeNode{
+						{"file", "", false, nil},
+					}},
+				}},
 			},
-			want:    &fileTreeNode{"/", "", true, []*fileTreeNode{etcWithFile, varWithFile}},
+			want: &fileTreeNode{"/", "", true, []*fileTreeNode{
+				{"etc", "", true, []*fileTreeNode{
+					{"file", "", false, nil}},
+				},
+				{"var", "", true, []*fileTreeNode{
+					{"file", "", false, nil}},
+				},
+			}},
+
 			wantErr: false,
 		},
 		{
 			name: "delete /etc/file",
 			args: args{
-				original: rootWithEtcTreeNode,
-				updated:  rootWithEtcWithDeleteFileTreeNode,
+				original: &fileTreeNode{"/", "", true, []*fileTreeNode{
+					{"etc", "", true, []*fileTreeNode{
+						{"file", "", false, nil},
+					}},
+				}},
+				updated: &fileTreeNode{"/", "", true, []*fileTreeNode{
+					{"etc", "", true, []*fileTreeNode{
+						{".wh.file", "", false, nil},
+					}},
+				}},
 			},
-			want:    &fileTreeNode{"/", "", true, []*fileTreeNode{{"etc", "", true, []*fileTreeNode{}}}},
+			want: &fileTreeNode{"/", "", true, []*fileTreeNode{
+				{"etc", "", true, []*fileTreeNode{}},
+			}},
 			wantErr: false,
 		},
 		{
 			name: "delete /etc/file and add /var/file",
 			args: args{
-				original: rootWithEtcTreeNode,
-				updated:  rootWithEtcWithDeleteFileAndAddVarFileTreeNode,
+				original: &fileTreeNode{"/", "", true, []*fileTreeNode{
+					{"etc", "", true, []*fileTreeNode{
+						{"file", "", false, nil},
+					}},
+				}},
+				updated: &fileTreeNode{"/", "", true, []*fileTreeNode{
+					{"etc", "", true, []*fileTreeNode{
+						{".wh.file", "", false, nil},
+					}},
+					{"var", "", false, []*fileTreeNode{
+						{"file", "", false, nil},
+					}},
+				}},
 			},
-			want:    &fileTreeNode{"/", "", true, []*fileTreeNode{{"etc", "", true, []*fileTreeNode{}}, varWithFile}},
+			want: &fileTreeNode{"/", "", true, []*fileTreeNode{
+				{"etc", "", true, []*fileTreeNode{}},
+				{"var", "", false, []*fileTreeNode{
+					{"file", "", false, nil},
+				}},
+			}},
 			wantErr: false,
 		},
 	}
 
+	defaultOpts := getStringOpts{showLinks: true, depth: 99999}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			got, err := mergeFileTrees(tt.args.original, tt.args.updated)
@@ -128,7 +175,9 @@ func Test_mergeFileTrees(t *testing.T) {
 				return
 			}
 			if !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("mergeFileTrees() got:\n%v, want:\n%v", got, tt.want)
+				t.Errorf("mergeFileTrees() got:\n%v, want:\n%v",
+					got.getString("", defaultOpts, true, false),
+					tt.want.getString("", defaultOpts, true, false))
 			}
 		})
 	}