Move "image_export" to graph/export.go

Signed-off-by: Solomon Hykes <solomon@docker.com>
Upstream-commit: 6e28d11d1fde757cf5b9418a2e752717d854f3f3
Component: engine

components/engine/graph/export.go

@@ -0,0 +1,147 @@
+package graph
+
+import (
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/docker/docker/archive"
+	"github.com/docker/docker/engine"
+	"github.com/docker/docker/pkg/parsers"
+	"github.com/docker/docker/utils"
+)
+
+// CmdImageExport exports all images with the given tag. All versions
+// containing the same tag are exported. The resulting output is an
+// uncompressed tar ball.
+// name is the set of tags to export.
+// out is the writer where the images are written to.
+func (s *TagStore) CmdImageExport(job *engine.Job) engine.Status {
+	if len(job.Args) != 1 {
+		return job.Errorf("Usage: %s IMAGE\n", job.Name)
+	}
+	name := job.Args[0]
+	// get image json
+	tempdir, err := ioutil.TempDir("", "docker-export-")
+	if err != nil {
+		return job.Error(err)
+	}
+	defer os.RemoveAll(tempdir)
+
+	utils.Debugf("Serializing %s", name)
+
+	rootRepoMap := map[string]Repository{}
+	rootRepo, err := s.Get(name)
+	if err != nil {
+		return job.Error(err)
+	}
+	if rootRepo != nil {
+		// this is a base repo name, like 'busybox'
+
+		for _, id := range rootRepo {
+			if err := s.exportImage(job.Eng, id, tempdir); err != nil {
+				return job.Error(err)
+			}
+		}
+		rootRepoMap[name] = rootRepo
+	} else {
+		img, err := s.LookupImage(name)
+		if err != nil {
+			return job.Error(err)
+		}
+		if img != nil {
+			// This is a named image like 'busybox:latest'
+			repoName, repoTag := parsers.ParseRepositoryTag(name)
+			if err := s.exportImage(job.Eng, img.ID, tempdir); err != nil {
+				return job.Error(err)
+			}
+			// check this length, because a lookup of a truncated has will not have a tag
+			// and will not need to be added to this map
+			if len(repoTag) > 0 {
+				rootRepoMap[repoName] = Repository{repoTag: img.ID}
+			}
+		} else {
+			// this must be an ID that didn't get looked up just right?
+			if err := s.exportImage(job.Eng, name, tempdir); err != nil {
+				return job.Error(err)
+			}
+		}
+	}
+	// write repositories, if there is something to write
+	if len(rootRepoMap) > 0 {
+		rootRepoJson, _ := json.Marshal(rootRepoMap)
+
+		if err := ioutil.WriteFile(path.Join(tempdir, "repositories"), rootRepoJson, os.FileMode(0644)); err != nil {
+			return job.Error(err)
+		}
+	} else {
+		utils.Debugf("There were no repositories to write")
+	}
+
+	fs, err := archive.Tar(tempdir, archive.Uncompressed)
+	if err != nil {
+		return job.Error(err)
+	}
+	defer fs.Close()
+
+	if _, err := io.Copy(job.Stdout, fs); err != nil {
+		return job.Error(err)
+	}
+	utils.Debugf("End Serializing %s", name)
+	return engine.StatusOK
+}
+
+// FIXME: this should be a top-level function, not a class method
+func (s *TagStore) exportImage(eng *engine.Engine, name, tempdir string) error {
+	for n := name; n != ""; {
+		// temporary directory
+		tmpImageDir := path.Join(tempdir, n)
+		if err := os.Mkdir(tmpImageDir, os.FileMode(0755)); err != nil {
+			if os.IsExist(err) {
+				return nil
+			}
+			return err
+		}
+
+		var version = "1.0"
+		var versionBuf = []byte(version)
+
+		if err := ioutil.WriteFile(path.Join(tmpImageDir, "VERSION"), versionBuf, os.FileMode(0644)); err != nil {
+			return err
+		}
+
+		// serialize json
+		json, err := os.Create(path.Join(tmpImageDir, "json"))
+		if err != nil {
+			return err
+		}
+		job := eng.Job("image_inspect", n)
+		job.SetenvBool("raw", true)
+		job.Stdout.Add(json)
+		if err := job.Run(); err != nil {
+			return err
+		}
+
+		// serialize filesystem
+		fsTar, err := os.Create(path.Join(tmpImageDir, "layer.tar"))
+		if err != nil {
+			return err
+		}
+		job = eng.Job("image_tarlayer", n)
+		job.Stdout.Add(fsTar)
+		if err := job.Run(); err != nil {
+			return err
+		}
+
+		// find parent
+		job = eng.Job("image_get", n)
+		info, _ := job.Stdout.AddEnv()
+		if err := job.Run(); err != nil {
+			return err
+		}
+		n = info.Get("Parent")
+	}
+	return nil
+}