Store container metadata in boltdb buckets

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

containers/storage.go

@@ -2,7 +2,6 @@ package containers
 
 import (
 	"context"
-	"encoding/json"
 
 	"github.com/boltdb/bolt"
 	"github.com/pkg/errors"
@@ -25,6 +24,11 @@ func IsExists(err error) bool {
 var (
 	bucketKeyStorageVersion = []byte("v1")
 	bucketKeyContainers     = []byte("containers")
+	bucketKeyLabels         = []byte("labels")
+	bucketKeyImage          = []byte("image")
+	bucketKeyRuntime        = []byte("runtime")
+	bucketKeySpec           = []byte("spec")
+	bucketKeyRootFS         = []byte("rootfs")
 )
 
 type storage struct {
@@ -38,19 +42,14 @@ func NewStore(tx *bolt.Tx) Store {
 }
 
 func (s *storage) Get(ctx context.Context, id string) (Container, error) {
-	bkt := s.bucket()
+	bkt := getContainerBucket(s.tx, id)
 	if bkt == nil {
 		return Container{}, errors.Wrap(ErrNotFound, "bucket does not exist")
 	}
 
-	cb := bkt.Get([]byte(id))
-	if len(cb) == 0 {
-		return Container{}, errors.Wrap(ErrNotFound, "no content for id")
-	}
-
-	var container Container
-	if err := json.Unmarshal(cb, &container); err != nil {
-		return Container{}, errors.Wrap(err, "failed to unmarshal container")
+	container := Container{ID: id}
+	if err := readContainer(&container, bkt); err != nil {
+		return Container{}, errors.Wrap(err, "failed to read container")
 	}
 
 	return container, nil
@@ -58,14 +57,19 @@ func (s *storage) Get(ctx context.Context, id string) (Container, error) {
 
 func (s *storage) List(ctx context.Context, filter string) ([]Container, error) {
 	containers := []Container{}
-	bkt := s.bucket()
+	bkt := getContainersBucket(s.tx)
 	if bkt == nil {
 		return containers, nil
 	}
 	err := bkt.ForEach(func(k, v []byte) error {
+		cbkt := bkt.Bucket(k)
+		if cbkt == nil {
+			return nil
+		}
 		container := Container{ID: string(k)}
-		if err := json.Unmarshal(v, &container); err != nil {
-			return errors.Wrap(err, "failed to unmarshal container")
+
+		if err := readContainer(&container, cbkt); err != nil {
+			return errors.Wrap(err, "failed to read container")
 		}
 		containers = append(containers, container)
 		return nil
@@ -78,69 +82,140 @@ func (s *storage) List(ctx context.Context, filter string) ([]Container, error)
 }
 
 func (s *storage) Create(ctx context.Context, container Container) (Container, error) {
-	bkt, err := s.createBucket()
+	bkt, err := createContainersBucket(s.tx)
 	if err != nil {
 		return Container{}, err
 	}
 
-	b := bkt.Get([]byte(container.ID))
-	if len(b) > 0 {
-		return Container{}, errors.Wrap(ErrExists, "content for id already exists")
-	}
-
-	b, err = json.Marshal(container)
+	cbkt, err := bkt.CreateBucket([]byte(container.ID))
 	if err != nil {
+		if err == bolt.ErrBucketExists {
+			err = errors.Wrap(ErrExists, "content for id already exists")
+		}
 		return Container{}, err
 	}
 
-	return container, bkt.Put([]byte(container.ID), b)
+	if err := writeContainer(&container, cbkt); err != nil {
+		return Container{}, errors.Wrap(err, "failed to write container")
+	}
+
+	return container, nil
 }
 
 func (s *storage) Update(ctx context.Context, container Container) (Container, error) {
-	bkt, err := s.createBucket()
-	if err != nil {
-		return Container{}, err
+	bkt := getContainersBucket(s.tx)
+	if bkt == nil {
+		return Container{}, errors.Wrap(ErrNotFound, "no containers")
 	}
 
-	b := bkt.Get([]byte(container.ID))
-	if len(b) == 0 {
+	cbkt := bkt.Bucket([]byte(container.ID))
+	if cbkt == nil {
 		return Container{}, errors.Wrap(ErrNotFound, "no content for id")
 	}
 
-	b, err = json.Marshal(container)
-	if err != nil {
-		return Container{}, err
+	if err := writeContainer(&container, cbkt); err != nil {
+		return Container{}, errors.Wrap(err, "failed to write container")
 	}
 
-	return container, bkt.Put([]byte(container.ID), b)
+	return container, nil
 }
 
 func (s *storage) Delete(ctx context.Context, id string) error {
-	bkt, err := s.createBucket()
+	bkt := getContainersBucket(s.tx)
+	if bkt == nil {
+		return errors.Wrap(ErrNotFound, "no containers")
+	}
+
+	err := bkt.DeleteBucket([]byte(id))
+	if err == bolt.ErrBucketNotFound {
+		return errors.Wrap(ErrNotFound, "no content for id")
+	}
+	return err
+}
+
+func readContainer(container *Container, bkt *bolt.Bucket) error {
+	return bkt.ForEach(func(k, v []byte) error {
+		switch string(k) {
+		case string(bucketKeyImage):
+			container.Image = string(v)
+		case string(bucketKeyRuntime):
+			container.Runtime = string(v)
+		case string(bucketKeySpec):
+			container.Spec = v
+		case string(bucketKeyRootFS):
+			container.RootFS = string(v)
+		case string(bucketKeyLabels):
+			lbkt := bkt.Bucket(bucketKeyLabels)
+			if lbkt == nil {
+				return nil
+			}
+			container.Labels = map[string]string{}
+			if err := lbkt.ForEach(func(k, v []byte) error {
+				container.Labels[string(k)] = string(v)
+				return nil
+			}); err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+}
+
+func writeContainer(container *Container, bkt *bolt.Bucket) error {
+	for _, v := range [][2][]byte{
+		{bucketKeyImage, []byte(container.Image)},
+		{bucketKeyRuntime, []byte(container.Runtime)},
+		{bucketKeySpec, container.Spec},
+		{bucketKeyRootFS, []byte(container.RootFS)},
+	} {
+		if err := bkt.Put(v[0], v[1]); err != nil {
+			return err
+		}
+	}
+	// Remove existing labels to keep from merging
+	if lbkt := bkt.Bucket(bucketKeyLabels); lbkt != nil {
+		if err := bkt.DeleteBucket(bucketKeyLabels); err != nil {
+			return err
+		}
+	}
+	lbkt, err := bkt.CreateBucket(bucketKeyLabels)
 	if err != nil {
 		return err
 	}
-
-	b := bkt.Get([]byte(id))
-	if len(b) == 0 {
-		return errors.Wrap(ErrNotFound, "no content for id")
+	for k, v := range container.Labels {
+		if err := lbkt.Put([]byte(k), []byte(v)); err != nil {
+			return err
+		}
 	}
-
-	return bkt.Delete([]byte(id))
+	return nil
 }
 
-func (s *storage) bucket() *bolt.Bucket {
-	bkt := s.tx.Bucket(bucketKeyStorageVersion)
-	if bkt == nil {
-		return nil
-	}
-	return bkt.Bucket(bucketKeyContainers)
-}
-
-func (s *storage) createBucket() (*bolt.Bucket, error) {
-	bkt, err := s.tx.CreateBucketIfNotExists(bucketKeyStorageVersion)
+func createContainersBucket(tx *bolt.Tx) (*bolt.Bucket, error) {
+	bkt, err := tx.CreateBucketIfNotExists(bucketKeyStorageVersion)
 	if err != nil {
 		return nil, err
 	}
 	return bkt.CreateBucketIfNotExists(bucketKeyContainers)
 }
+
+func getContainersBucket(tx *bolt.Tx) *bolt.Bucket {
+	return getBucket(tx, bucketKeyStorageVersion, bucketKeyContainers)
+}
+
+func getContainerBucket(tx *bolt.Tx, id string) *bolt.Bucket {
+	return getBucket(tx, bucketKeyStorageVersion, bucketKeyContainers, []byte(id))
+}
+
+func getBucket(tx *bolt.Tx, keys ...[]byte) *bolt.Bucket {
+	bkt := tx.Bucket(keys[0])
+
+	for _, key := range keys[1:] {
+		if bkt == nil {
+			break
+		}
+		bkt = bkt.Bucket(key)
+	}
+
+	return bkt
+}