dockerfile: add cache-from support

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

frontend/dockerfile/builder/build.go

@@ -20,6 +20,7 @@ const (
 	LocalNameDockerfile   = "dockerfile"
 	keyTarget             = "target"
 	keyFilename           = "filename"
+	keyCacheFrom          = "cache-from"
 	exporterImageConfig   = "containerimage.config"
 	defaultDockerfileName = "Dockerfile"
 	dockerignoreFilename  = ".dockerignore"
@@ -57,7 +58,7 @@ func Build(ctx context.Context, c client.Client) error {
 	eg, ctx2 := errgroup.WithContext(ctx)
 	var dtDockerfile []byte
 	eg.Go(func() error {
-		ref, err := c.Solve(ctx2, def.ToPB(), "", "", nil, false)
+		ref, err := c.Solve(ctx2, def.ToPB(), "", nil, nil, false)
 		if err != nil {
 			return err
 		}
@@ -83,7 +84,7 @@ func Build(ctx context.Context, c client.Client) error {
 		if err != nil {
 			return err
 		}
-		ref, err := c.Solve(ctx2, def.ToPB(), "", "", nil, false)
+		ref, err := c.Solve(ctx2, def.ToPB(), "", nil, nil, false)
 		if err != nil {
 			return err
 		}
@@ -125,7 +126,12 @@ func Build(ctx context.Context, c client.Client) error {
 		return err
 	}
 
-	_, err = c.Solve(ctx, def.ToPB(), "", opts["cache-from"], map[string][]byte{
+	var cacheFrom []string
+	if cacheFromStr := opts[keyCacheFrom]; cacheFromStr != "" {
+		cacheFrom = strings.Split(cacheFromStr, ",")
+	}
+
+	_, err = c.Solve(ctx, def.ToPB(), "", cacheFrom, map[string][]byte{
 		exporterImageConfig: config,
 	}, true)
 	if err != nil {

frontend/dockerfile/forward.go

@@ -26,11 +26,11 @@ type bridgeClient struct {
 	refs         []*ref
 }
 
-func (c *bridgeClient) Solve(ctx context.Context, def *pb.Definition, f string, importRef string, exporterAttr map[string][]byte, final bool) (client.Reference, error) {
+func (c *bridgeClient) Solve(ctx context.Context, def *pb.Definition, f string, cacheImportRefs []string, exporterAttr map[string][]byte, final bool) (client.Reference, error) {
 	r, exporterAttrRes, err := c.FrontendLLBBridge.Solve(ctx, frontend.SolveRequest{
-		Definition:     def,
-		Frontend:       f,
-		ImportCacheRef: importRef,
+		Definition:      def,
+		Frontend:        f,
+		ImportCacheRefs: cacheImportRefs,
 	})
 	if err != nil {
 		return nil, err

frontend/gateway/client/client.go

@@ -9,7 +9,7 @@ import (
 
 // TODO: make this take same options as LLBBridge. Add Return()
 type Client interface {
-	Solve(ctx context.Context, def *pb.Definition, frontend string, importRef string, exporterAttr map[string][]byte, final bool) (Reference, error)
+	Solve(ctx context.Context, def *pb.Definition, frontend string, cacheImportRefs []string, exporterAttr map[string][]byte, final bool) (Reference, error)
 	ResolveImageConfig(ctx context.Context, ref string) (digest.Digest, []byte, error)
 	Opts() map[string]string
 	SessionID() string

solver-next/llbsolver/bridge.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/docker/distribution/reference"
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/cache/cacheimport"
 	"github.com/moby/buildkit/executor"
@@ -32,16 +33,23 @@ func (b *llbBridge) Solve(ctx context.Context, req frontend.SolveRequest) (res s
 		b.cmsMu.Lock()
 		var cm solver.CacheManager
 		if prevCm, ok := b.cms[ref]; !ok {
-			cm = newLazyCacheManager(ref, func() (solver.CacheManager, error) {
-				var cmNew solver.CacheManager
-				if err := b.builder.Call(ctx, "importing cache manifest from "+ref, func(ctx context.Context) error {
-					cmNew, err = b.ci.Resolve(ctx, ref)
-					return err
-				}); err != nil {
-					return nil, err
-				}
-				return cmNew, nil
-			})
+			r, err := reference.ParseNormalizedNamed(ref)
+			if err != nil {
+				return nil, nil, err
+			}
+			ref = reference.TagNameOnly(r).String()
+			func(ref string) {
+				cm = newLazyCacheManager(ref, func() (solver.CacheManager, error) {
+					var cmNew solver.CacheManager
+					if err := b.builder.Call(ctx, "importing cache manifest from "+ref, func(ctx context.Context) error {
+						cmNew, err = b.ci.Resolve(ctx, ref)
+						return err
+					}); err != nil {
+						return nil, err
+					}
+					return cmNew, nil
+				})
+			}(ref)
 			b.cms[ref] = cm
 		} else {
 			cm = prevCm