Respond with 404 when the source image can not be found in OpenStack Swift (#903)

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 ### Fix
 - Fix trimming of CMYK images.
+- Respond with 404 when the source image can not be found in OpenStack Object Storage.
 
 ## [3.6.0] - 2022-06-13
 ### Add

transport/swift/swift.go

@@ -2,7 +2,9 @@ package swift
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -46,11 +48,24 @@ func (t transport) RoundTrip(req *http.Request) (resp *http.Response, err error)
 
 	object, objectHeaders, err := t.con.ObjectOpen(req.Context(), container, objectName, false, make(swift.Headers))
 
+	header := make(http.Header)
+
 	if err != nil {
-		return nil, fmt.Errorf("error opening object: %v", err)
+		if errors.Is(err, swift.ObjectNotFound) || errors.Is(err, swift.ContainerNotFound) {
+			return &http.Response{
+				StatusCode: http.StatusNotFound,
+				Proto:      "HTTP/1.0",
+				ProtoMajor: 1,
+				ProtoMinor: 0,
+				Header:     header,
+				Body:       io.NopCloser(strings.NewReader(err.Error())),
+				Close:      false,
+				Request:    req,
+			}, nil
 		}
 
-	header := make(http.Header)
+		return nil, fmt.Errorf("error opening object: %v", err)
+	}
 
 	if config.ETagEnabled {
 		if etag, ok := objectHeaders["Etag"]; ok {

transport/swift/swift_test.go

@@ -90,6 +90,24 @@ func (s *SwiftTestSuite) TestRoundTripWithETagDisabledReturns200() {
 	require.Equal(s.T(), 200, response.StatusCode)
 }
 
+func (s *SwiftTestSuite) TestRoundTripReturns404WhenObjectNotFound() {
+	config.ETagEnabled = true
+	request, _ := http.NewRequest("GET", "swift://test/foo/not-here.png", nil)
+
+	response, err := s.transport.RoundTrip(request)
+	require.Nil(s.T(), err)
+	require.Equal(s.T(), 404, response.StatusCode)
+}
+
+func (s *SwiftTestSuite) TestRoundTripReturns404WhenContainerNotFound() {
+	config.ETagEnabled = true
+	request, _ := http.NewRequest("GET", "swift://invalid/foo/test.png", nil)
+
+	response, err := s.transport.RoundTrip(request)
+	require.Nil(s.T(), err)
+	require.Equal(s.T(), 404, response.StatusCode)
+}
+
 func (s *SwiftTestSuite) TestRoundTripWithETagEnabled() {
 	config.ETagEnabled = true
 	request, _ := http.NewRequest("GET", "swift://test/foo/test.png", nil)