Add Evaluate(Ref) Gateway API

client/build.go

@@ -113,6 +113,19 @@ func (g *gatewayClientForBuild) StatFile(ctx context.Context, in *gatewayapi.Sta
  return g.gateway.StatFile(ctx, in, opts...)
 }
 
+func (g *gatewayClientForBuild) Evaluate(ctx context.Context, in *gatewayapi.EvaluateRequest, opts ...grpc.CallOption) (*gatewayapi.EvaluateResponse, error) {
+ if err := g.caps.Supports(gatewayapi.CapGatewayEvaluate); err != nil {
+ if err2 := g.caps.Supports(gatewayapi.CapStatFile); err2 != nil {
+ return nil, err
+ }
+ ctx = buildid.AppendToOutgoingContext(ctx, g.buildID)
+ _, err := g.gateway.StatFile(ctx, &gatewayapi.StatFileRequest{Ref: in.Ref, Path: "."}, opts...)
+ return &gatewayapi.EvaluateResponse{}, err
+ }
+ ctx = buildid.AppendToOutgoingContext(ctx, g.buildID)
+ return g.gateway.Evaluate(ctx, in, opts...)
+}
+
 func (g *gatewayClientForBuild) Ping(ctx context.Context, in *gatewayapi.PingRequest, opts ...grpc.CallOption) (*gatewayapi.PongResponse, error) {
  ctx = buildid.AppendToOutgoingContext(ctx, g.buildID)
  return g.gateway.Ping(ctx, in, opts...)

control/gateway/gateway.go

@@ -111,6 +111,14 @@ func (gwf *GatewayForwarder) ReadFile(ctx context.Context, req *gwapi.ReadFileRe
  return fwd.ReadFile(ctx, req)
 }
 
+func (gwf *GatewayForwarder) Evaluate(ctx context.Context, req *gwapi.EvaluateRequest) (*gwapi.EvaluateResponse, error) {
+ fwd, err := gwf.lookupForwarder(ctx)
+ if err != nil {
+ return nil, errors.Wrap(err, "forwarding Evaluate")
+ }
+ return fwd.Evaluate(ctx, req)
+}
+
 func (gwf *GatewayForwarder) Ping(ctx context.Context, req *gwapi.PingRequest) (*gwapi.PongResponse, error) {
  fwd, err := gwf.lookupForwarder(ctx)
  if err != nil {

frontend/frontend_test.go

@@ -31,6 +31,7 @@ func TestFrontendIntegration(t *testing.T) {
  testRefReadFile,
  testRefReadDir,
  testRefStatFile,
+ testRefEvaluate,
  testReturnNil,
  ))
 }
@@ -291,6 +292,55 @@ func testRefStatFile(t *testing.T, sb integration.Sandbox) {
  require.NoError(t, err)
 }
 
+func testRefEvaluate(t *testing.T, sb integration.Sandbox) {
+ ctx := sb.Context()
+
+ c, err := client.New(ctx, sb.Address())
+ require.NoError(t, err)
+ defer c.Close()
+
+ frontend := func(ctx context.Context, c gateway.Client) (*gateway.Result, error) {
+ st := llb.Scratch().File(llb.Mkfile("/test", 0666, []byte{}))
+ def, err := st.Marshal(ctx)
+ if err != nil {
+ return nil, err
+ }
+ res, err := c.Solve(ctx, gateway.SolveRequest{
+ Definition: def.ToPB(),
+ })
+ if err != nil {
+ return nil, err
+ }
+ ref, err := res.SingleRef()
+ if err != nil {
+ return nil, err
+ }
+
+ st = llb.Scratch().File(llb.Mkfile("/test/dir-does-not-exist", 0666, []byte{}))
+ def, err = st.Marshal(ctx)
+ if err != nil {
+ return nil, err
+ }
+ res, err = c.Solve(ctx, gateway.SolveRequest{
+ Definition: def.ToPB(),
+ })
+ if err != nil {
+ return nil, err
+ }
+ ref2, err := res.SingleRef()
+ if err != nil {
+ return nil, err
+ }
+
+ require.NoError(t, ref.Evaluate(ctx))
+ require.Error(t, ref2.Evaluate(ctx))
+ return gateway.NewResult(), nil
+ }
+
+ _, err = c.Build(ctx, client.SolveOpt{}, "", frontend, nil)
+ require.NoError(t, err)
+}
+
 func tmpdir(t *testing.T, appliers ...fstest.Applier) (string, error) {
  tmpdir := t.TempDir()
  if err := fstest.Apply(appliers...).Apply(tmpdir); err != nil {

frontend/gateway/client/client.go

@@ -91,6 +91,7 @@ type ContainerProcess interface {
 
 type Reference interface {
  ToState() (llb.State, error)
+ Evaluate(ctx context.Context) error
  ReadFile(ctx context.Context, req ReadRequest) ([]byte, error)
  StatFile(ctx context.Context, req StatRequest) (*fstypes.Stat, error)
  ReadDir(ctx context.Context, req ReadDirRequest) ([]*fstypes.Stat, error)

frontend/gateway/forwarder/forward.go

@@ -318,6 +318,14 @@ func (r *ref) ToState() (st llb.State, err error) {
  return llb.NewState(defop), nil
 }
 
+func (r *ref) Evaluate(ctx context.Context) error {
+ _, err := r.resultProxy.Result(ctx)
+ if err != nil {
+ return r.c.wrapSolveError(err)
+ }
+ return nil
+}
+
 func (r *ref) ReadFile(ctx context.Context, req client.ReadRequest) ([]byte, error) {
  m, err := r.getMountable(ctx)
  if err != nil {

frontend/gateway/gateway.go

@@ -754,15 +754,15 @@ func (lbf *llbBridgeForwarder) Solve(ctx context.Context, req *pb.SolveRequest)
  return resp, nil
 }
 
-func (lbf *llbBridgeForwarder) getImmutableRef(ctx context.Context, id, path string) (cache.ImmutableRef, error) {
+func (lbf *llbBridgeForwarder) getImmutableRef(ctx context.Context, id string) (cache.ImmutableRef, error) {
  lbf.mu.Lock()
  ref, ok := lbf.refs[id]
  lbf.mu.Unlock()
  if !ok {
- return nil, errors.Errorf("no such ref: %v", id)
+ return nil, errors.Errorf("no such ref: %s", id)
  }
  if ref == nil {
- return nil, errors.Wrap(os.ErrNotExist, path)
+ return nil, errors.Errorf("empty ref: %s", id)
  }
 
  r, err := ref.Result(ctx)
@@ -781,7 +781,7 @@ func (lbf *llbBridgeForwarder) getImmutableRef(ctx context.Context, id, path str
 func (lbf *llbBridgeForwarder) ReadFile(ctx context.Context, req *pb.ReadFileRequest) (*pb.ReadFileResponse, error) {
  ctx = tracing.ContextWithSpanFromContext(ctx, lbf.callCtx)
 
- ref, err := lbf.getImmutableRef(ctx, req.Ref, req.FilePath)
+ ref, err := lbf.getImmutableRef(ctx, req.Ref)
  if err != nil {
  return nil, err
  }
@@ -812,7 +812,7 @@ func (lbf *llbBridgeForwarder) ReadFile(ctx context.Context, req *pb.ReadFileReq
 func (lbf *llbBridgeForwarder) ReadDir(ctx context.Context, req *pb.ReadDirRequest) (*pb.ReadDirResponse, error) {
  ctx = tracing.ContextWithSpanFromContext(ctx, lbf.callCtx)
 
- ref, err := lbf.getImmutableRef(ctx, req.Ref, req.DirPath)
+ ref, err := lbf.getImmutableRef(ctx, req.Ref)
  if err != nil {
  return nil, err
  }
@@ -836,7 +836,7 @@ func (lbf *llbBridgeForwarder) ReadDir(ctx context.Context, req *pb.ReadDirReque
 func (lbf *llbBridgeForwarder) StatFile(ctx context.Context, req *pb.StatFileRequest) (*pb.StatFileResponse, error) {
  ctx = tracing.ContextWithSpanFromContext(ctx, lbf.callCtx)
 
- ref, err := lbf.getImmutableRef(ctx, req.Ref, req.Path)
+ ref, err := lbf.getImmutableRef(ctx, req.Ref)
  if err != nil {
  return nil, err
  }
@@ -852,6 +852,16 @@ func (lbf *llbBridgeForwarder) StatFile(ctx context.Context, req *pb.StatFileReq
  return &pb.StatFileResponse{Stat: st}, nil
 }
 
+func (lbf *llbBridgeForwarder) Evaluate(ctx context.Context, req *pb.EvaluateRequest) (*pb.EvaluateResponse, error) {
+ ctx = tracing.ContextWithSpanFromContext(ctx, lbf.callCtx)
+
+ _, err := lbf.getImmutableRef(ctx, req.Ref)
+ if err != nil {
+ return nil, err
+ }
+ return &pb.EvaluateResponse{}, nil
+}
+
 func (lbf *llbBridgeForwarder) Ping(context.Context, *pb.PingRequest) (*pb.PongResponse, error) {
  workers := lbf.workers.WorkerInfos()
  pbWorkers := make([]*apitypes.WorkerRecord, 0, len(workers))

frontend/gateway/grpcclient/client.go

@@ -387,30 +387,15 @@ func (c *grpcClient) Solve(ctx context.Context, creq client.SolveRequest) (res *
  if c.caps.Supports(pb.CapGatewayEvaluateSolve) == nil {
  req.Evaluate = creq.Evaluate
  } else {
- // If evaluate is not supported, fallback to running Stat(".") in order to
- // trigger an evaluation of the result.
+ // If evaluate is not supported, fallback to running Stat(".") in
+ // order to trigger an evaluation of the result.
  defer func() {
  if res == nil {
  return
  }
-
- var (
- id string
- ref client.Reference
- )
- ref, err = res.SingleRef()
- if err != nil {
- for refID := range res.Refs {
- id = refID
- break
- }
- } else {
- id = ref.(*reference).id
- }
-
- _, err = c.client.StatFile(ctx, &pb.StatFileRequest{
- Ref: id,
- Path: ".",
+ err = res.EachRef(func(ref client.Reference) error {
+ _, err := ref.StatFile(ctx, client.StatRequest{Path: "."})
+ return err
  })
  }()
  }
@@ -1054,6 +1039,15 @@ func (r *reference) ToState() (st llb.State, err error) {
  return llb.NewState(defop), nil
 }
 
+func (r *reference) Evaluate(ctx context.Context) error {
+ req := &pb.EvaluateRequest{Ref: r.id}
+ _, err := r.c.client.Evaluate(ctx, req)
+ if err != nil {
+ return err
+ }
+ return nil
+}
+
 func (r *reference) ReadFile(ctx context.Context, req client.ReadRequest) ([]byte, error) {
  rfr := &pb.ReadFileRequest{FilePath: req.Filename, Ref: r.id}
  if r := req.Range; r != nil {

frontend/gateway/pb/caps.go

@@ -56,6 +56,8 @@ const (
  // errors.
  CapGatewayEvaluateSolve apicaps.CapID = "gateway.solve.evaluate"
 
+ CapGatewayEvaluate apicaps.CapID = "gateway.evaluate"
+
  // CapGatewayWarnings is the capability to log warnings from frontend
  CapGatewayWarnings apicaps.CapID = "gateway.warnings"
 
@@ -198,6 +200,13 @@ func init() {
  Status: apicaps.CapStatusExperimental,
  })
 
+ Caps.Init(apicaps.Cap{
+ ID: CapGatewayEvaluate,
+ Name: "gateway evaluate",
+ Enabled: true,
+ Status: apicaps.CapStatusExperimental,
+ })
+
  Caps.Init(apicaps.Cap{
  ID: CapGatewayWarnings,
  Name: "logging warnings",