imagetools inspect: add --format flag

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/moby/buildkit/util/resolver/retryhandler/retry.go

@@ -0,0 +1,72 @@
+package retryhandler
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net"
+	"syscall"
+	"time"
+
+	"github.com/containerd/containerd/images"
+	remoteserrors "github.com/containerd/containerd/remotes/errors"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+func New(f images.HandlerFunc, logger func([]byte)) images.HandlerFunc {
+	return func(ctx context.Context, desc ocispecs.Descriptor) ([]ocispecs.Descriptor, error) {
+		backoff := time.Second
+		for {
+			descs, err := f(ctx, desc)
+			if err != nil {
+				select {
+				case <-ctx.Done():
+					return nil, err
+				default:
+					if !retryError(err) {
+						return nil, err
+					}
+				}
+				if logger != nil {
+					logger([]byte(fmt.Sprintf("error: %v\n", err.Error())))
+				}
+			} else {
+				return descs, nil
+			}
+			// backoff logic
+			if backoff >= 8*time.Second {
+				return nil, err
+			}
+			if logger != nil {
+				logger([]byte(fmt.Sprintf("retrying in %v\n", backoff)))
+			}
+			time.Sleep(backoff)
+			backoff *= 2
+		}
+	}
+}
+
+func retryError(err error) bool {
+	// Retry on 5xx errors
+	var errUnexpectedStatus remoteserrors.ErrUnexpectedStatus
+	if errors.As(err, &errUnexpectedStatus) &&
+		errUnexpectedStatus.StatusCode >= 500 &&
+		errUnexpectedStatus.StatusCode <= 599 {
+		return true
+	}
+
+	if errors.Is(err, io.EOF) || errors.Is(err, syscall.ECONNRESET) || errors.Is(err, syscall.EPIPE) || errors.Is(err, net.ErrClosed) {
+		return true
+	}
+	// catches TLS timeout or other network-related temporary errors
+	if ne, ok := errors.Cause(err).(net.Error); ok && ne.Temporary() {
+		return true
+	}
+	// https://github.com/containerd/containerd/pull/4724
+	if errors.Cause(err).Error() == "no response" {
+		return true
+	}
+
+	return false
+}