history: add error details to history inspect command

For failed builds, show the source with error location and last
logs for vertex that caused the error. When debug mode is on,
stacktrace is printed.

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

commands/history/inspect.go

@@ -1,6 +1,7 @@
 package history
 
 import (
+	"bytes"
 	"cmp"
 	"context"
 	"encoding/json"
@@ -24,16 +25,24 @@ import (
 	"github.com/docker/buildx/util/confutil"
 	"github.com/docker/buildx/util/desktop"
 	"github.com/docker/cli/cli/command"
+	"github.com/docker/cli/cli/debug"
 	slsa "github.com/in-toto/in-toto-golang/in_toto/slsa_provenance/common"
 	slsa02 "github.com/in-toto/in-toto-golang/in_toto/slsa_provenance/v0.2"
 	controlapi "github.com/moby/buildkit/api/services/control"
+	"github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/solver/errdefs"
 	provenancetypes "github.com/moby/buildkit/solver/llbsolver/provenance/types"
+	"github.com/moby/buildkit/util/grpcerrors"
+	"github.com/moby/buildkit/util/stack"
 	"github.com/opencontainers/go-digest"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"github.com/tonistiigi/go-csvvalue"
+	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	proto "google.golang.org/protobuf/proto"
 )
 
 type inspectOptions struct {
@@ -186,14 +195,14 @@ func runInspect(ctx context.Context, dockerCli command.Cli, opts inspectOptions)
 
 	fmt.Fprintf(tw, "Started:\t%s\n", rec.CreatedAt.AsTime().Format("2006-01-02 15:04:05"))
 	var duration time.Duration
-	var status string
+	var statusStr string
 	if rec.CompletedAt != nil {
 		duration = rec.CompletedAt.AsTime().Sub(rec.CreatedAt.AsTime())
 	} else {
 		duration = rec.currentTimestamp.Sub(rec.CreatedAt.AsTime())
-		status = " (running)"
+		statusStr = " (running)"
 	}
-	fmt.Fprintf(tw, "Duration:\t%s%s\n", formatDuration(duration), status)
+	fmt.Fprintf(tw, "Duration:\t%s%s\n", formatDuration(duration), statusStr)
 	if rec.Error != nil {
 		if codes.Code(rec.Error.Code) == codes.Canceled {
 			fmt.Fprintf(tw, "Status:\tCanceled\n")
@@ -309,6 +318,46 @@ func runInspect(ctx context.Context, dockerCli command.Cli, opts inspectOptions)
 		fmt.Fprintln(dockerCli.Out())
 	}
 
+	if rec.ExternalError != nil {
+		dt, err := content.ReadBlob(ctx, store, ociDesc(rec.ExternalError))
+		if err != nil {
+			return errors.Wrapf(err, "failed to read external error %s", rec.ExternalError.Digest)
+		}
+		var st spb.Status
+		if err := proto.Unmarshal(dt, &st); err != nil {
+			return errors.Wrapf(err, "failed to unmarshal external error %s", rec.ExternalError.Digest)
+		}
+		retErr := grpcerrors.FromGRPC(status.ErrorProto(&st))
+		for _, s := range errdefs.Sources(retErr) {
+			s.Print(dockerCli.Out())
+		}
+
+		var ve *errdefs.VertexError
+		if errors.As(retErr, &ve) {
+			dgst, err := digest.Parse(ve.Vertex.Digest)
+			if err != nil {
+				return errors.Wrapf(err, "failed to parse vertex digest %s", ve.Vertex.Digest)
+			}
+			name, logs, err := loadVertexLogs(ctx, c, rec.Ref, dgst, 16)
+			if err != nil {
+				return errors.Wrapf(err, "failed to load vertex logs %s", dgst)
+			}
+			if len(logs) > 0 {
+				fmt.Fprintf(dockerCli.Out(), "\n => %s:\n", name)
+				for _, l := range logs {
+					fmt.Fprintln(dockerCli.Out(), l)
+				}
+				fmt.Fprintln(dockerCli.Out())
+			}
+		}
+
+		if debug.IsEnabled() {
+			fmt.Fprintf(dockerCli.Out(), "\n%+v\n", stack.Formatter(retErr))
+		} else if len(stack.Traces(retErr)) > 0 {
+			fmt.Fprintf(dockerCli.Out(), "Enable --debug to see stack traces for error\n")
+		}
+	}
+
 	fmt.Fprintf(dockerCli.Out(), "Print build logs: docker buildx history logs %s\n", rec.Ref)
 
 	fmt.Fprintf(dockerCli.Out(), "View build in Docker Desktop: %s\n", desktop.BuildURL(rec.Ref))
@@ -342,6 +391,73 @@ func inspectCmd(dockerCli command.Cli, rootOpts RootOptions) *cobra.Command {
 	return cmd
 }
 
+func loadVertexLogs(ctx context.Context, c *client.Client, ref string, dgst digest.Digest, limit int) (string, []string, error) {
+	st, err := c.ControlClient().Status(ctx, &controlapi.StatusRequest{
+		Ref: ref,
+	})
+	if err != nil {
+		return "", nil, err
+	}
+
+	var name string
+	var logs []string
+	lastState := map[int]int{}
+
+loop0:
+	for {
+		select {
+		case <-ctx.Done():
+			st.CloseSend()
+			return "", nil, context.Cause(ctx)
+		default:
+			ev, err := st.Recv()
+			if err != nil {
+				if errors.Is(err, io.EOF) {
+					break loop0
+				}
+				return "", nil, err
+			}
+			ss := client.NewSolveStatus(ev)
+			for _, v := range ss.Vertexes {
+				if v.Digest == dgst {
+					name = v.Name
+					break
+				}
+			}
+			for _, l := range ss.Logs {
+				if l.Vertex == dgst {
+					parts := bytes.Split(l.Data, []byte("\n"))
+					for i, p := range parts {
+						var wrote bool
+						if i == 0 {
+							idx, ok := lastState[l.Stream]
+							if ok && idx != -1 {
+								logs[idx] = logs[idx] + string(p)
+								wrote = true
+							}
+						}
+						if !wrote {
+							if len(p) > 0 {
+								logs = append(logs, string(p))
+							}
+							lastState[l.Stream] = len(logs) - 1
+						}
+						if i == len(parts)-1 && len(p) == 0 {
+							lastState[l.Stream] = -1
+						}
+					}
+				}
+			}
+		}
+	}
+
+	if limit > 0 && len(logs) > limit {
+		logs = logs[len(logs)-limit:]
+	}
+
+	return name, logs, nil
+}
+
 type attachment struct {
 	platform *ocispecs.Platform
 	descr    ocispecs.Descriptor