update

extractor/docker.go

@@ -2,14 +2,66 @@ package extractor
 
 import (
 	"archive/tar"
+	"encoding/json"
 	"io"
 	"io/ioutil"
 	"path"
+	"path/filepath"
+	"strings"
 )
 
+type manifest struct {
+	Config   string   `json:"Config"`
+	RepoTags []string `json:"RepoTags"`
+	Layers   []string `json:"Layers"`
+}
+
 type DockerExtractor struct{}
 
-func (d DockerExtractor) ExtractFiles(layer io.ReadCloser, filenames []string) (FilesMap, error) {
+func (d DockerExtractor) Extract(r io.ReadCloser, filenames []string) (FilesMap, error) {
+	manifests := make([]manifest, 0)
+	filesInLayers := make(map[string]FilesMap)
+	tr := tar.NewReader(r)
+	for {
+		header, err := tr.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, ErrCouldNotExtract
+		}
+		switch {
+		case header.Name == "manifest.json":
+			if err := json.NewDecoder(tr).Decode(&manifests); err != nil {
+				return nil, err
+			}
+		case strings.HasSuffix(header.Name, ".tar"):
+			layerID := filepath.Base(filepath.Dir(header.Name))
+			files, err := d.ExtractFiles(tr, filenames)
+			if err != nil {
+				return nil, err
+			}
+			filesInLayers[layerID] = files
+		//case strings.HasSuffix(header.Name, ".json"):
+		//	if err := json.NewDecoder(tr).Decode(&imageMeta); err != nil {
+		//		return nil, err
+		//	}
+		//	imageMetas[header.Name] = imageMeta
+		default:
+		}
+	}
+	filesMap := map[string][]byte{}
+	for _, layerID := range manifests[0].Layers {
+		layerID := strings.Split(layerID, "/")[0]
+		for k, v := range filesInLayers[layerID] {
+			filesMap[k] = v
+		}
+	}
+
+	return filesMap, nil
+
+}
+func (d DockerExtractor) ExtractFiles(layer io.Reader, filenames []string) (FilesMap, error) {
 	data := make(map[string][]byte)
 
 	tr := tar.NewReader(layer)