Initial commit

vendor/github.com/hyperhq/hypercli/layer/filestore.go

@@ -0,0 +1,326 @@
+package layer
+
+import (
+	"compress/gzip"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/distribution/digest"
+	"github.com/hyperhq/hypercli/pkg/ioutils"
+)
+
+var (
+	stringIDRegexp      = regexp.MustCompile(`^[a-f0-9]{64}(-init)?$`)
+	supportedAlgorithms = []digest.Algorithm{
+		digest.SHA256,
+		// digest.SHA384, // Currently not used
+		// digest.SHA512, // Currently not used
+	}
+)
+
+type fileMetadataStore struct {
+	root string
+}
+
+type fileMetadataTransaction struct {
+	store *fileMetadataStore
+	root  string
+}
+
+// NewFSMetadataStore returns an instance of a metadata store
+// which is backed by files on disk using the provided root
+// as the root of metadata files.
+func NewFSMetadataStore(root string) (MetadataStore, error) {
+	if err := os.MkdirAll(root, 0700); err != nil {
+		return nil, err
+	}
+	return &fileMetadataStore{
+		root: root,
+	}, nil
+}
+
+func (fms *fileMetadataStore) getLayerDirectory(layer ChainID) string {
+	dgst := digest.Digest(layer)
+	return filepath.Join(fms.root, string(dgst.Algorithm()), dgst.Hex())
+}
+
+func (fms *fileMetadataStore) getLayerFilename(layer ChainID, filename string) string {
+	return filepath.Join(fms.getLayerDirectory(layer), filename)
+}
+
+func (fms *fileMetadataStore) getMountDirectory(mount string) string {
+	return filepath.Join(fms.root, "mounts", mount)
+}
+
+func (fms *fileMetadataStore) getMountFilename(mount, filename string) string {
+	return filepath.Join(fms.getMountDirectory(mount), filename)
+}
+
+func (fms *fileMetadataStore) StartTransaction() (MetadataTransaction, error) {
+	tmpDir := filepath.Join(fms.root, "tmp")
+	if err := os.MkdirAll(tmpDir, 0755); err != nil {
+		return nil, err
+	}
+
+	td, err := ioutil.TempDir(tmpDir, "layer-")
+	if err != nil {
+		return nil, err
+	}
+	// Create a new tempdir
+	return &fileMetadataTransaction{
+		store: fms,
+		root:  td,
+	}, nil
+}
+
+func (fm *fileMetadataTransaction) SetSize(size int64) error {
+	content := fmt.Sprintf("%d", size)
+	return ioutil.WriteFile(filepath.Join(fm.root, "size"), []byte(content), 0644)
+}
+
+func (fm *fileMetadataTransaction) SetParent(parent ChainID) error {
+	return ioutil.WriteFile(filepath.Join(fm.root, "parent"), []byte(digest.Digest(parent).String()), 0644)
+}
+
+func (fm *fileMetadataTransaction) SetDiffID(diff DiffID) error {
+	return ioutil.WriteFile(filepath.Join(fm.root, "diff"), []byte(digest.Digest(diff).String()), 0644)
+}
+
+func (fm *fileMetadataTransaction) SetCacheID(cacheID string) error {
+	return ioutil.WriteFile(filepath.Join(fm.root, "cache-id"), []byte(cacheID), 0644)
+}
+
+func (fm *fileMetadataTransaction) TarSplitWriter(compressInput bool) (io.WriteCloser, error) {
+	f, err := os.OpenFile(filepath.Join(fm.root, "tar-split.json.gz"), os.O_TRUNC|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return nil, err
+	}
+	var wc io.WriteCloser
+	if compressInput {
+		wc = gzip.NewWriter(f)
+	} else {
+		wc = f
+	}
+
+	return ioutils.NewWriteCloserWrapper(wc, func() error {
+		wc.Close()
+		return f.Close()
+	}), nil
+}
+
+func (fm *fileMetadataTransaction) Commit(layer ChainID) error {
+	finalDir := fm.store.getLayerDirectory(layer)
+	if err := os.MkdirAll(filepath.Dir(finalDir), 0755); err != nil {
+		return err
+	}
+	return os.Rename(fm.root, finalDir)
+}
+
+func (fm *fileMetadataTransaction) Cancel() error {
+	return os.RemoveAll(fm.root)
+}
+
+func (fm *fileMetadataTransaction) String() string {
+	return fm.root
+}
+
+func (fms *fileMetadataStore) GetSize(layer ChainID) (int64, error) {
+	content, err := ioutil.ReadFile(fms.getLayerFilename(layer, "size"))
+	if err != nil {
+		return 0, err
+	}
+
+	size, err := strconv.ParseInt(string(content), 10, 64)
+	if err != nil {
+		return 0, err
+	}
+
+	return size, nil
+}
+
+func (fms *fileMetadataStore) GetParent(layer ChainID) (ChainID, error) {
+	content, err := ioutil.ReadFile(fms.getLayerFilename(layer, "parent"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return "", nil
+		}
+		return "", err
+	}
+
+	dgst, err := digest.ParseDigest(strings.TrimSpace(string(content)))
+	if err != nil {
+		return "", err
+	}
+
+	return ChainID(dgst), nil
+}
+
+func (fms *fileMetadataStore) GetDiffID(layer ChainID) (DiffID, error) {
+	content, err := ioutil.ReadFile(fms.getLayerFilename(layer, "diff"))
+	if err != nil {
+		return "", err
+	}
+
+	dgst, err := digest.ParseDigest(strings.TrimSpace(string(content)))
+	if err != nil {
+		return "", err
+	}
+
+	return DiffID(dgst), nil
+}
+
+func (fms *fileMetadataStore) GetCacheID(layer ChainID) (string, error) {
+	contentBytes, err := ioutil.ReadFile(fms.getLayerFilename(layer, "cache-id"))
+	if err != nil {
+		return "", err
+	}
+	content := strings.TrimSpace(string(contentBytes))
+
+	if !stringIDRegexp.MatchString(content) {
+		return "", errors.New("invalid cache id value")
+	}
+
+	return content, nil
+}
+
+func (fms *fileMetadataStore) TarSplitReader(layer ChainID) (io.ReadCloser, error) {
+	fz, err := os.Open(fms.getLayerFilename(layer, "tar-split.json.gz"))
+	if err != nil {
+		return nil, err
+	}
+	f, err := gzip.NewReader(fz)
+	if err != nil {
+		return nil, err
+	}
+
+	return ioutils.NewReadCloserWrapper(f, func() error {
+		f.Close()
+		return fz.Close()
+	}), nil
+}
+
+func (fms *fileMetadataStore) SetMountID(mount string, mountID string) error {
+	if err := os.MkdirAll(fms.getMountDirectory(mount), 0755); err != nil {
+		return err
+	}
+	return ioutil.WriteFile(fms.getMountFilename(mount, "mount-id"), []byte(mountID), 0644)
+}
+
+func (fms *fileMetadataStore) SetInitID(mount string, init string) error {
+	if err := os.MkdirAll(fms.getMountDirectory(mount), 0755); err != nil {
+		return err
+	}
+	return ioutil.WriteFile(fms.getMountFilename(mount, "init-id"), []byte(init), 0644)
+}
+
+func (fms *fileMetadataStore) SetMountParent(mount string, parent ChainID) error {
+	if err := os.MkdirAll(fms.getMountDirectory(mount), 0755); err != nil {
+		return err
+	}
+	return ioutil.WriteFile(fms.getMountFilename(mount, "parent"), []byte(digest.Digest(parent).String()), 0644)
+}
+
+func (fms *fileMetadataStore) GetMountID(mount string) (string, error) {
+	contentBytes, err := ioutil.ReadFile(fms.getMountFilename(mount, "mount-id"))
+	if err != nil {
+		return "", err
+	}
+	content := strings.TrimSpace(string(contentBytes))
+
+	if !stringIDRegexp.MatchString(content) {
+		return "", errors.New("invalid mount id value")
+	}
+
+	return content, nil
+}
+
+func (fms *fileMetadataStore) GetInitID(mount string) (string, error) {
+	contentBytes, err := ioutil.ReadFile(fms.getMountFilename(mount, "init-id"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return "", nil
+		}
+		return "", err
+	}
+	content := strings.TrimSpace(string(contentBytes))
+
+	if !stringIDRegexp.MatchString(content) {
+		return "", errors.New("invalid init id value")
+	}
+
+	return content, nil
+}
+
+func (fms *fileMetadataStore) GetMountParent(mount string) (ChainID, error) {
+	content, err := ioutil.ReadFile(fms.getMountFilename(mount, "parent"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return "", nil
+		}
+		return "", err
+	}
+
+	dgst, err := digest.ParseDigest(strings.TrimSpace(string(content)))
+	if err != nil {
+		return "", err
+	}
+
+	return ChainID(dgst), nil
+}
+
+func (fms *fileMetadataStore) List() ([]ChainID, []string, error) {
+	var ids []ChainID
+	for _, algorithm := range supportedAlgorithms {
+		fileInfos, err := ioutil.ReadDir(filepath.Join(fms.root, string(algorithm)))
+		if err != nil {
+			if os.IsNotExist(err) {
+				continue
+			}
+			return nil, nil, err
+		}
+
+		for _, fi := range fileInfos {
+			if fi.IsDir() && fi.Name() != "mounts" {
+				dgst := digest.NewDigestFromHex(string(algorithm), fi.Name())
+				if err := dgst.Validate(); err != nil {
+					logrus.Debugf("Ignoring invalid digest %s:%s", algorithm, fi.Name())
+				} else {
+					ids = append(ids, ChainID(dgst))
+				}
+			}
+		}
+	}
+
+	fileInfos, err := ioutil.ReadDir(filepath.Join(fms.root, "mounts"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return ids, []string{}, nil
+		}
+		return nil, nil, err
+	}
+
+	var mounts []string
+	for _, fi := range fileInfos {
+		if fi.IsDir() {
+			mounts = append(mounts, fi.Name())
+		}
+	}
+
+	return ids, mounts, nil
+}
+
+func (fms *fileMetadataStore) Remove(layer ChainID) error {
+	return os.RemoveAll(fms.getLayerDirectory(layer))
+}
+
+func (fms *fileMetadataStore) RemoveMount(mount string) error {
+	return os.RemoveAll(fms.getMountDirectory(mount))
+}