Avoid duplicate image configuration parsing logic

Don't bother trying to find and parse the image's configuration blob
after we've already done it; just reuse the value.  This frees us from
making the assumption that the last blob which was committed to local
storage was the image's configuration blob.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

libkpod/image/imageData.go

@@ -1,13 +1,12 @@
 package image
 
 import (
-	"encoding/json"
 	"time"
 
 	"github.com/containers/image/docker/reference"
 	"github.com/containers/storage"
+	"github.com/kubernetes-incubator/cri-o/cmd/kpod/docker"
 	"github.com/kubernetes-incubator/cri-o/libkpod/driver"
-	digest "github.com/opencontainers/go-digest"
 	ociv1 "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 )
@@ -22,7 +21,7 @@ type ImageData struct {
 	Comment         string
 	Created         *time.Time
 	Container       string
-	ContainerConfig containerConfig
+	ContainerConfig docker.Config
 	Author          string
 	Config          ociv1.ImageConfig
 	Architecture    string
@@ -33,27 +32,6 @@ type ImageData struct {
 	RootFS          ociv1.RootFS
 }
 
-type containerConfig struct {
-	Hostname     string
-	Domainname   string
-	User         string
-	AttachStdin  bool
-	AttachStdout bool
-	AttachStderr bool
-	Tty          bool
-	OpenStdin    bool
-	StdinOnce    bool
-	Env          []string
-	Cmd          []string
-	ArgsEscaped  bool
-	Image        digest.Digest
-	Volumes      map[string]interface{}
-	WorkingDir   string
-	Entrypoint   []string
-	Labels       interface{}
-	OnBuild      []string
-}
-
 type rootFS struct {
 	Type   string
 	Layers []string
@@ -96,34 +74,6 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 	if err != nil {
 		return nil, errors.Wrapf(err, "error reading image %q", name)
 	}
-	blobDigests, err := getDigests(*img)
-	if err != nil {
-		return nil, err
-	}
-
-	var bigData interface{}
-	ctrConfig := containerConfig{}
-	container := ""
-	if len(blobDigests) > 0 {
-		bd, err := store.ImageBigData(img.ID, string(blobDigests[len(blobDigests)-1]))
-		if err != nil {
-			return nil, err
-		}
-		err = json.Unmarshal(bd, &bigData)
-		if err != nil {
-			return nil, err
-		}
-
-		container = (bigData.(map[string]interface{})["container"]).(string)
-		cc, err := json.MarshalIndent((bigData.(map[string]interface{})["container_config"]).(map[string]interface{}), "", "    ")
-		if err != nil {
-			return nil, err
-		}
-		err = json.Unmarshal(cc, &ctrConfig)
-		if err != nil {
-			return nil, err
-		}
-	}
 
 	tags, digests, err := ParseImageNames(img.Names)
 	if err != nil {
@@ -166,8 +116,8 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 		Parent:          string(cid.Docker.Parent),
 		Comment:         cid.OCIv1.History[0].Comment,
 		Created:         cid.OCIv1.Created,
-		Container:       container,
+		Container:       cid.Docker.Container,
-		ContainerConfig: ctrConfig,
+		ContainerConfig: cid.Docker.ContainerConfig,
 		Author:          cid.OCIv1.Author,
 		Config:          cid.OCIv1.Config,
 		Architecture:    cid.OCIv1.Architecture,
@@ -181,15 +131,3 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 		RootFS: cid.OCIv1.RootFS,
 	}, nil
 }
-
-func getDigests(img storage.Image) ([]digest.Digest, error) {
-	metadata, err := ParseMetadata(img)
-	if err != nil {
-		return nil, err
-	}
-	digests := []digest.Digest{}
-	for _, blob := range metadata.Blobs {
-		digests = append(digests, blob.Digest)
-	}
-	return digests, nil
-}