Update presign post URL resolution to use the exact result from EndpointResolverV2

.changelog/5702f383099a47a5860f5ab25cda67a1.json

@@ -0,0 +1,8 @@
+{
+    "id": "5702f383-099a-47a5-860f-5ab25cda67a1",
+    "type": "bugfix",
+    "description": "Update presign post URL resolution to use the exact result from EndpointResolverV2",
+    "modules": [
+        "service/s3"
+    ]
+}

codegen/smithy-aws-go-codegen/src/main/java/software/amazon/smithy/aws/go/codegen/customization/s3/StoreResolvedUri.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.aws.go.codegen.customization.s3;
+
+import software.amazon.smithy.aws.go.codegen.AwsGoDependency;
+import software.amazon.smithy.aws.go.codegen.customization.S3ModelUtils;
+import software.amazon.smithy.go.codegen.GoSettings;
+import software.amazon.smithy.go.codegen.GoWriter;
+import software.amazon.smithy.go.codegen.integration.GoIntegration;
+import software.amazon.smithy.model.Model;
+
+import java.util.Map;
+
+/**
+ * Stores the endpoint resolved by EndpointResolverV2
+ */
+public class StoreResolvedUri implements GoIntegration {
+    @Override
+    public void renderPostEndpointResolutionHook(GoSettings settings, GoWriter writer, Model model) {
+        if (!S3ModelUtils.isServiceS3(model, settings.getService(model))) return;
+        writer.writeGoTemplate(
+                """
+                        ctx = $internalContext:L.$setFunc:L(ctx, endpt.URI.String())
+                        """,
+                Map.of(
+                        "internalContext", AwsGoDependency.INTERNAL_CONTEXT.getAlias(),
+                        "setFunc", "SetS3ResolvedURI")
+        );
+    }
+}

codegen/smithy-aws-go-codegen/src/main/resources/META-INF/services/software.amazon.smithy.go.codegen.integration.GoIntegration

@@ -74,6 +74,7 @@ software.amazon.smithy.aws.go.codegen.customization.RemoveDefaults
 software.amazon.smithy.aws.go.codegen.customization.auth.S3ExpressAuthScheme
 software.amazon.smithy.aws.go.codegen.customization.S3BucketContext
 software.amazon.smithy.aws.go.codegen.customization.s3.ExpressDefaultChecksum
+software.amazon.smithy.aws.go.codegen.customization.s3.StoreResolvedUri
 software.amazon.smithy.aws.go.codegen.customization.auth.GlobalAnonymousOption
 software.amazon.smithy.aws.go.codegen.customization.CloudFrontKVSSigV4a
 software.amazon.smithy.aws.go.codegen.customization.BackfillProtocolTestServiceTrait

internal/context/context.go

@@ -10,6 +10,7 @@ import (
 type s3BackendKey struct{}
 type checksumInputAlgorithmKey struct{}
 type clockSkew struct{}
+type s3resolvedURI struct{}
 
 const (
 	// S3BackendS3Express identifies the S3Express backend
@@ -50,3 +51,14 @@ func GetAttemptSkewContext(ctx context.Context) time.Duration {
 	x, _ := middleware.GetStackValue(ctx, clockSkew{}).(time.Duration)
 	return x
 }
+
+// SetS3ResolvedURI sets the URI as resolved by the EndpointResolverV2
+func SetS3ResolvedURI(ctx context.Context, value string) context.Context {
+	return middleware.WithStackValue(ctx, s3resolvedURI{}, value)
+}
+
+// GetS3ResolvedURI gets the URI as resolved by EndpointResolverV2
+func GetS3ResolvedURI(ctx context.Context) string {
+	v, _ := middleware.GetStackValue(ctx, s3resolvedURI{}).(string)
+	return v
+}

service/s3/presign_post.go

@@ -8,7 +8,6 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
-	"net/url"
 	"strings"
 	"time"
 
@@ -211,10 +210,6 @@ func (s *presignPostRequestMiddleware) HandleFinalize(
 ) (
 	out middleware.FinalizeOutput, metadata middleware.Metadata, err error,
 ) {
-	req, ok := in.Request.(*smithyhttp.Request)
-	if !ok {
-		return out, metadata, fmt.Errorf("unexpected request middleware type %T", in.Request)
-	}
 
 	input := getOperationInput(ctx)
 	asS3Put, ok := input.(*PutObjectInput)
@@ -230,8 +225,7 @@ func (s *presignPostRequestMiddleware) HandleFinalize(
 		return out, metadata, fmt.Errorf("PutObject input does not have a key input")
 	}
 
-	httpReq := req.Build(ctx)
-	u := httpReq.URL.String()
+	uri := internalcontext.GetS3ResolvedURI(ctx)
 
 	signingName := awsmiddleware.GetSigningName(ctx)
 	signingRegion := awsmiddleware.GetSigningRegion(ctx)
@@ -265,22 +259,14 @@ func (s *presignPostRequestMiddleware) HandleFinalize(
 		}
 	}
 
-	// Other middlewares may set default values on the URL on the path or as query params. Remove them
-	baseURL := toBaseURL(u)
-
 	out.Result = &PresignedPostRequest{
-		URL:    baseURL,
+		URL:    uri,
 		Values: fields,
 	}
 
 	return out, metadata, nil
 }
 
-func toBaseURL(fullURL string) string {
-	a, _ := url.Parse(fullURL)
-	return a.Scheme + "://" + a.Host
-}
-
 // Adapted from existing PresignConverter middleware
 func (c presignPostConverter) ConvertToPresignMiddleware(stack *middleware.Stack, options Options) (err error) {
 	stack.Build.Remove("UserAgent")

service/s3/presign_post_test.go

@@ -19,11 +19,13 @@ func TestPresignPutObject(t *testing.T) {
 	defer mockTime(fixedTime)()
 
 	cases := map[string]struct {
-		input           PutObjectInput
-		options         []func(*PresignPostOptions)
-		expectedExpires time.Time
-		expectedURL     string
-		region          string
+		input            PutObjectInput
+		options          []func(*PresignPostOptions)
+		expectedExpires  time.Time
+		expectedURL      string
+		region           string
+		pathStyleEnabled bool
+		BaseEndpoint     string
 	}{
 		"sample": {
 			input: PutObjectInput{
@@ -66,6 +68,23 @@ func TestPresignPutObject(t *testing.T) {
 			},
 			expectedURL: "https://mfzwi23gnjvgw.mrap.accesspoint.s3-global.amazonaws.com",
 		},
+		"use path style bucket hosting pattern": {
+			input: PutObjectInput{
+				Bucket: aws.String("bucket"),
+				Key:    aws.String("key"),
+			},
+			expectedURL:      "https://s3.us-west-2.amazonaws.com/bucket",
+			pathStyleEnabled: true,
+		},
+		"use path style bucket with custom baseEndpoint": {
+			input: PutObjectInput{
+				Bucket: aws.String("bucket"),
+				Key:    aws.String("key"),
+			},
+			expectedURL:      "https://s3.custom-domain.com/bucket",
+			pathStyleEnabled: true,
+			BaseEndpoint:     "https://s3.custom-domain.com",
+		},
 	}
 	for name, tc := range cases {
 		t.Run(name, func(t *testing.T) {
@@ -81,8 +100,12 @@ func TestPresignPutObject(t *testing.T) {
 					return aws.NopRetryer{}
 				},
 			}
-
-			presignClient := NewPresignClient(NewFromConfig(cfg))
+			presignClient := NewPresignClient(NewFromConfig(cfg, func(options *Options) {
+				options.UsePathStyle = tc.pathStyleEnabled
+				if tc.BaseEndpoint != "" {
+					options.BaseEndpoint = aws.String(tc.BaseEndpoint)
+				}
+			}))
 			postObject, err := presignClient.PresignPostObject(ctx, &tc.input, tc.options...)
 			if err != nil {
 				t.Error(err)