errdefs: move GetHTTPErrorStatusCode to api/server/httpstatus

This reverts the changes made in 2a9c987e5a72549775ffa4dc31595ceff4f06a78, which
moved the GetHTTPErrorStatusCode() utility to the errdefs package.

While it seemed to make sense at the time to have the errdefs package provide
conversion both from HTTP status codes errdefs and the reverse, a side-effect
of the move was that the errdefs package now had a dependency on various external
modules, to handle conversio of errors coming from those sub-systems, such as;

- github.com/containerd/containerd
- github.com/docker/distribution
- google.golang.org/grpc

This patch moves the conversion from (errdef-) errors to HTTP status-codes to a
 api/server/httpstatus package, which is only used by the API server, and should
not be needed by client-code using the errdefs package.

The MakeErrorHandler() utility was moved to the API server itself, as that's the
only place it's used. While the same applies to the GetHTTPErrorStatusCode func,
I opted for keeping that in its own package for a slightly cleaner interface.

Why not move it into the api/server/httputils package?

The api/server/httputils package is also imported in the client package, which
uses the httputils.ParseForm() and httputils.HijackConnection() functions as
part of the TestTLSCloseWriter() test. While this is only used in tests, I
wanted to avoid introducing the indirect depdencencies outside of the api/server
code.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

api/server/errorhandler.go

@@ -0,0 +1,34 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/docker/docker/api/server/httpstatus"
+	"github.com/docker/docker/api/server/httputils"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/versions"
+	"github.com/gorilla/mux"
+	"google.golang.org/grpc/status"
+)
+
+// makeErrorHandler makes an HTTP handler that decodes a Docker error and
+// returns it in the response.
+func makeErrorHandler(err error) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		statusCode := httpstatus.FromError(err)
+		vars := mux.Vars(r)
+		if apiVersionSupportsJSONErrors(vars["version"]) {
+			response := &types.ErrorResponse{
+				Message: err.Error(),
+			}
+			_ = httputils.WriteJSON(w, statusCode, response)
+		} else {
+			http.Error(w, status.Convert(err).Message(), statusCode)
+		}
+	}
+}
+
+func apiVersionSupportsJSONErrors(version string) bool {
+	const firstAPIVersionWithJSONErrors = "1.23"
+	return version == "" || versions.GreaterThan(version, firstAPIVersionWithJSONErrors)
+}

api/server/httpstatus/status.go

@@ -0,0 +1,150 @@
+package httpstatus // import "github.com/docker/docker/api/server/httpstatus"
+
+import (
+	"fmt"
+	"net/http"
+
+	containerderrors "github.com/containerd/containerd/errdefs"
+	"github.com/docker/distribution/registry/api/errcode"
+	"github.com/docker/docker/errdefs"
+	"github.com/sirupsen/logrus"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+type causer interface {
+	Cause() error
+}
+
+// FromError retrieves status code from error message.
+func FromError(err error) int {
+	if err == nil {
+		logrus.WithFields(logrus.Fields{"error": err}).Error("unexpected HTTP error handling")
+		return http.StatusInternalServerError
+	}
+
+	var statusCode int
+
+	// Stop right there
+	// Are you sure you should be adding a new error class here? Do one of the existing ones work?
+
+	// Note that the below functions are already checking the error causal chain for matches.
+	switch {
+	case errdefs.IsNotFound(err):
+		statusCode = http.StatusNotFound
+	case errdefs.IsInvalidParameter(err):
+		statusCode = http.StatusBadRequest
+	case errdefs.IsConflict(err):
+		statusCode = http.StatusConflict
+	case errdefs.IsUnauthorized(err):
+		statusCode = http.StatusUnauthorized
+	case errdefs.IsUnavailable(err):
+		statusCode = http.StatusServiceUnavailable
+	case errdefs.IsForbidden(err):
+		statusCode = http.StatusForbidden
+	case errdefs.IsNotModified(err):
+		statusCode = http.StatusNotModified
+	case errdefs.IsNotImplemented(err):
+		statusCode = http.StatusNotImplemented
+	case errdefs.IsSystem(err) || errdefs.IsUnknown(err) || errdefs.IsDataLoss(err) || errdefs.IsDeadline(err) || errdefs.IsCancelled(err):
+		statusCode = http.StatusInternalServerError
+	default:
+		statusCode = statusCodeFromGRPCError(err)
+		if statusCode != http.StatusInternalServerError {
+			return statusCode
+		}
+		statusCode = statusCodeFromContainerdError(err)
+		if statusCode != http.StatusInternalServerError {
+			return statusCode
+		}
+		statusCode = statusCodeFromDistributionError(err)
+		if statusCode != http.StatusInternalServerError {
+			return statusCode
+		}
+		if e, ok := err.(causer); ok {
+			return FromError(e.Cause())
+		}
+
+		logrus.WithFields(logrus.Fields{
+			"module":     "api",
+			"error_type": fmt.Sprintf("%T", err),
+		}).Debugf("FIXME: Got an API for which error does not match any expected type!!!: %+v", err)
+	}
+
+	if statusCode == 0 {
+		statusCode = http.StatusInternalServerError
+	}
+
+	return statusCode
+}
+
+// statusCodeFromGRPCError returns status code according to gRPC error
+func statusCodeFromGRPCError(err error) int {
+	switch status.Code(err) {
+	case codes.InvalidArgument: // code 3
+		return http.StatusBadRequest
+	case codes.NotFound: // code 5
+		return http.StatusNotFound
+	case codes.AlreadyExists: // code 6
+		return http.StatusConflict
+	case codes.PermissionDenied: // code 7
+		return http.StatusForbidden
+	case codes.FailedPrecondition: // code 9
+		return http.StatusBadRequest
+	case codes.Unauthenticated: // code 16
+		return http.StatusUnauthorized
+	case codes.OutOfRange: // code 11
+		return http.StatusBadRequest
+	case codes.Unimplemented: // code 12
+		return http.StatusNotImplemented
+	case codes.Unavailable: // code 14
+		return http.StatusServiceUnavailable
+	default:
+		// codes.Canceled(1)
+		// codes.Unknown(2)
+		// codes.DeadlineExceeded(4)
+		// codes.ResourceExhausted(8)
+		// codes.Aborted(10)
+		// codes.Internal(13)
+		// codes.DataLoss(15)
+		return http.StatusInternalServerError
+	}
+}
+
+// statusCodeFromDistributionError returns status code according to registry errcode
+// code is loosely based on errcode.ServeJSON() in docker/distribution
+func statusCodeFromDistributionError(err error) int {
+	switch errs := err.(type) {
+	case errcode.Errors:
+		if len(errs) < 1 {
+			return http.StatusInternalServerError
+		}
+		if _, ok := errs[0].(errcode.ErrorCoder); ok {
+			return statusCodeFromDistributionError(errs[0])
+		}
+	case errcode.ErrorCoder:
+		return errs.ErrorCode().Descriptor().HTTPStatusCode
+	}
+	return http.StatusInternalServerError
+}
+
+// statusCodeFromContainerdError returns status code for containerd errors when
+// consumed directly (not through gRPC)
+func statusCodeFromContainerdError(err error) int {
+	switch {
+	case containerderrors.IsInvalidArgument(err):
+		return http.StatusBadRequest
+	case containerderrors.IsNotFound(err):
+		return http.StatusNotFound
+	case containerderrors.IsAlreadyExists(err):
+		return http.StatusConflict
+	case containerderrors.IsFailedPrecondition(err):
+		return http.StatusPreconditionFailed
+	case containerderrors.IsUnavailable(err):
+		return http.StatusServiceUnavailable
+	case containerderrors.IsNotImplemented(err):
+		return http.StatusNotImplemented
+	default:
+		return http.StatusInternalServerError
+	}
+}

api/server/httputils/errors_deprecated.go

@@ -1,9 +0,0 @@
-package httputils // import "github.com/docker/docker/api/server/httputils"
-import "github.com/docker/docker/errdefs"
-
-// GetHTTPErrorStatusCode retrieves status code from error message.
-//
-// Deprecated: use errdefs.GetHTTPErrorStatusCode
-func GetHTTPErrorStatusCode(err error) int {
-	return errdefs.GetHTTPErrorStatusCode(err)
-}

api/server/httputils/httputils.go

@@ -7,13 +7,9 @@ import (
 	"net/http"
 	"strings"
 
-	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/docker/errdefs"
-	"github.com/gorilla/mux"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
-	"google.golang.org/grpc/status"
 )
 
 // APIVersionKey is the client's requested API version.
@@ -92,28 +88,6 @@ func VersionFromContext(ctx context.Context) string {
 	return ""
 }
 
-// MakeErrorHandler makes an HTTP handler that decodes a Docker error and
-// returns it in the response.
-func MakeErrorHandler(err error) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		statusCode := errdefs.GetHTTPErrorStatusCode(err)
-		vars := mux.Vars(r)
-		if apiVersionSupportsJSONErrors(vars["version"]) {
-			response := &types.ErrorResponse{
-				Message: err.Error(),
-			}
-			_ = WriteJSON(w, statusCode, response)
-		} else {
-			http.Error(w, status.Convert(err).Message(), statusCode)
-		}
-	}
-}
-
-func apiVersionSupportsJSONErrors(version string) bool {
-	const firstAPIVersionWithJSONErrors = "1.23"
-	return version == "" || versions.GreaterThan(version, firstAPIVersionWithJSONErrors)
-}
-
 // matchesContentType validates the content type against the expected one
 func matchesContentType(contentType, expectedType string) bool {
 	mimetype, _, err := mime.ParseMediaType(contentType)

api/server/router/container/container_routes.go

@@ -10,6 +10,7 @@ import (
 	"syscall"
 
 	"github.com/containerd/containerd/platforms"
+	"github.com/docker/docker/api/server/httpstatus"
 	"github.com/docker/docker/api/server/httputils"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/backend"
@@ -641,7 +642,7 @@ func (s *containerRouter) postContainersAttach(ctx context.Context, w http.Respo
 		// Remember to close stream if error happens
 		conn, _, errHijack := hijacker.Hijack()
 		if errHijack == nil {
-			statusCode := errdefs.GetHTTPErrorStatusCode(err)
+			statusCode := httpstatus.FromError(err)
 			statusText := http.StatusText(statusCode)
 			fmt.Fprintf(conn, "HTTP/1.1 %d %s\r\nContent-Type: application/vnd.docker.raw-stream\r\n\r\n%s\r\n", statusCode, statusText, err.Error())
 			httputils.CloseStreams(conn)

api/server/server.go

@@ -7,12 +7,12 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/docker/docker/api/server/httpstatus"
 	"github.com/docker/docker/api/server/httputils"
 	"github.com/docker/docker/api/server/middleware"
 	"github.com/docker/docker/api/server/router"
 	"github.com/docker/docker/api/server/router/debug"
 	"github.com/docker/docker/dockerversion"
-	"github.com/docker/docker/errdefs"
 	"github.com/gorilla/mux"
 	"github.com/sirupsen/logrus"
 )
@@ -139,11 +139,11 @@ func (s *Server) makeHTTPHandler(handler httputils.APIFunc) http.HandlerFunc {
 		}
 
 		if err := handlerFunc(ctx, w, r, vars); err != nil {
-			statusCode := errdefs.GetHTTPErrorStatusCode(err)
+			statusCode := httpstatus.FromError(err)
 			if statusCode >= 500 {
 				logrus.Errorf("Handler for %s %s returned error: %v", r.Method, r.URL.Path, err)
 			}
-			httputils.MakeErrorHandler(err)(w, r)
+			makeErrorHandler(err)(w, r)
 		}
 	}
 }
@@ -184,7 +184,7 @@ func (s *Server) createMux() *mux.Router {
 		m.Path("/debug" + r.Path()).Handler(f)
 	}
 
-	notFoundHandler := httputils.MakeErrorHandler(pageNotFoundError{})
+	notFoundHandler := makeErrorHandler(pageNotFoundError{})
 	m.HandleFunc(versionMatcher+"/{path:.*}", notFoundHandler)
 	m.NotFoundHandler = notFoundHandler
 	m.MethodNotAllowedHandler = notFoundHandler

errdefs/http_helpers.go

@@ -1,78 +1,11 @@
 package errdefs // import "github.com/docker/docker/errdefs"
 
 import (
-	"fmt"
 	"net/http"
 
-	containerderrors "github.com/containerd/containerd/errdefs"
-	"github.com/docker/distribution/registry/api/errcode"
 	"github.com/sirupsen/logrus"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
 )
 
-// GetHTTPErrorStatusCode retrieves status code from error message.
-func GetHTTPErrorStatusCode(err error) int {
-	if err == nil {
-		logrus.WithFields(logrus.Fields{"error": err}).Error("unexpected HTTP error handling")
-		return http.StatusInternalServerError
-	}
-
-	var statusCode int
-
-	// Stop right there
-	// Are you sure you should be adding a new error class here? Do one of the existing ones work?
-
-	// Note that the below functions are already checking the error causal chain for matches.
-	switch {
-	case IsNotFound(err):
-		statusCode = http.StatusNotFound
-	case IsInvalidParameter(err):
-		statusCode = http.StatusBadRequest
-	case IsConflict(err):
-		statusCode = http.StatusConflict
-	case IsUnauthorized(err):
-		statusCode = http.StatusUnauthorized
-	case IsUnavailable(err):
-		statusCode = http.StatusServiceUnavailable
-	case IsForbidden(err):
-		statusCode = http.StatusForbidden
-	case IsNotModified(err):
-		statusCode = http.StatusNotModified
-	case IsNotImplemented(err):
-		statusCode = http.StatusNotImplemented
-	case IsSystem(err) || IsUnknown(err) || IsDataLoss(err) || IsDeadline(err) || IsCancelled(err):
-		statusCode = http.StatusInternalServerError
-	default:
-		statusCode = statusCodeFromGRPCError(err)
-		if statusCode != http.StatusInternalServerError {
-			return statusCode
-		}
-		statusCode = statusCodeFromContainerdError(err)
-		if statusCode != http.StatusInternalServerError {
-			return statusCode
-		}
-		statusCode = statusCodeFromDistributionError(err)
-		if statusCode != http.StatusInternalServerError {
-			return statusCode
-		}
-		if e, ok := err.(causer); ok {
-			return GetHTTPErrorStatusCode(e.Cause())
-		}
-
-		logrus.WithFields(logrus.Fields{
-			"module":     "api",
-			"error_type": fmt.Sprintf("%T", err),
-		}).Debugf("FIXME: Got an API for which error does not match any expected type!!!: %+v", err)
-	}
-
-	if statusCode == 0 {
-		statusCode = http.StatusInternalServerError
-	}
-
-	return statusCode
-}
-
 // FromStatusCode creates an errdef error, based on the provided HTTP status-code
 func FromStatusCode(err error, statusCode int) error {
 	if err == nil {
@@ -118,74 +51,3 @@ func FromStatusCode(err error, statusCode int) error {
 	}
 	return err
 }
-
-// statusCodeFromGRPCError returns status code according to gRPC error
-func statusCodeFromGRPCError(err error) int {
-	switch status.Code(err) {
-	case codes.InvalidArgument: // code 3
-		return http.StatusBadRequest
-	case codes.NotFound: // code 5
-		return http.StatusNotFound
-	case codes.AlreadyExists: // code 6
-		return http.StatusConflict
-	case codes.PermissionDenied: // code 7
-		return http.StatusForbidden
-	case codes.FailedPrecondition: // code 9
-		return http.StatusBadRequest
-	case codes.Unauthenticated: // code 16
-		return http.StatusUnauthorized
-	case codes.OutOfRange: // code 11
-		return http.StatusBadRequest
-	case codes.Unimplemented: // code 12
-		return http.StatusNotImplemented
-	case codes.Unavailable: // code 14
-		return http.StatusServiceUnavailable
-	default:
-		// codes.Canceled(1)
-		// codes.Unknown(2)
-		// codes.DeadlineExceeded(4)
-		// codes.ResourceExhausted(8)
-		// codes.Aborted(10)
-		// codes.Internal(13)
-		// codes.DataLoss(15)
-		return http.StatusInternalServerError
-	}
-}
-
-// statusCodeFromDistributionError returns status code according to registry errcode
-// code is loosely based on errcode.ServeJSON() in docker/distribution
-func statusCodeFromDistributionError(err error) int {
-	switch errs := err.(type) {
-	case errcode.Errors:
-		if len(errs) < 1 {
-			return http.StatusInternalServerError
-		}
-		if _, ok := errs[0].(errcode.ErrorCoder); ok {
-			return statusCodeFromDistributionError(errs[0])
-		}
-	case errcode.ErrorCoder:
-		return errs.ErrorCode().Descriptor().HTTPStatusCode
-	}
-	return http.StatusInternalServerError
-}
-
-// statusCodeFromContainerdError returns status code for containerd errors when
-// consumed directly (not through gRPC)
-func statusCodeFromContainerdError(err error) int {
-	switch {
-	case containerderrors.IsInvalidArgument(err):
-		return http.StatusBadRequest
-	case containerderrors.IsNotFound(err):
-		return http.StatusNotFound
-	case containerderrors.IsAlreadyExists(err):
-		return http.StatusConflict
-	case containerderrors.IsFailedPrecondition(err):
-		return http.StatusPreconditionFailed
-	case containerderrors.IsUnavailable(err):
-		return http.StatusServiceUnavailable
-	case containerderrors.IsNotImplemented(err):
-		return http.StatusNotImplemented
-	default:
-		return http.StatusInternalServerError
-	}
-}