fix: add non-vhostable buckets to path when using legacy endpoint res…

…olver (#2417)

.changelog/422df6b2a00a43a6a0eeac3c4f27c1a9.json

@@ -0,0 +1,8 @@
+{
+    "id": "422df6b2-a00a-43a6-a0ee-ac3c4f27c1a9",
+    "type": "bugfix",
+    "description": "Add non-vhostable buckets to request path when using legacy V1 endpoint resolver.",
+    "modules": [
+        "service/s3"
+    ]
+}

service/s3/internal/customizations/update_endpoint_test.go

@@ -55,6 +55,24 @@ func Test_UpdateEndpointBuild(t *testing.T) {
 					{"abc", "k:e,y", "https://abc.s3.mock-region.amazonaws.com/k%3Ae%2Cy?x-id=GetObject", ""},
 				},
 			},
+			"VirtualHostStyleBucketV1EndpointHTTPS": {
+				customEndpoint: &aws.Endpoint{
+					URL: "https://foo.bar",
+				},
+				tests: []s3BucketTest{
+					{"abc", "key", "https://abc.foo.bar/key?x-id=GetObject", ""},
+					{"a.b.c", "key", "https://foo.bar/a.b.c/key?x-id=GetObject", ""},
+				},
+			},
+			"VirtualHostStyleBucketV1EndpointHTTP": {
+				customEndpoint: &aws.Endpoint{
+					URL: "http://foo.bar",
+				},
+				tests: []s3BucketTest{
+					{"abc", "key", "http://abc.foo.bar/key?x-id=GetObject", ""},
+					{"a.b.c", "key", "http://a.b.c.foo.bar/key?x-id=GetObject", ""},
+				},
+			},
 			"Accelerate": {
 				useAccelerate: true,
 				tests: []s3BucketTest{

service/s3/serialize_immutable_hostname_bucket.go

@@ -3,9 +3,10 @@ package s3
 import (
 	"context"
 	"fmt"
-	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
 	"path"
 
+	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
+
 	"github.com/aws/aws-sdk-go-v2/internal/endpoints/awsrulesfn"
 	smithy "github.com/aws/smithy-go"
 	"github.com/aws/smithy-go/encoding/httpbinding"
@@ -38,16 +39,20 @@ func (m *serializeImmutableHostnameBucketMiddleware) HandleSerialize(
 	if !ok {
 		return out, metadata, &smithy.SerializationError{Err: fmt.Errorf("unknown transport type %T", in.Request)}
 	}
-	if !smithyhttp.GetHostnameImmutable(ctx) &&
-		!(awsmiddleware.GetRequiresLegacyEndpoints(ctx) && m.UsePathStyle) {
-		return next.HandleSerialize(ctx, in)
-	}
 
 	bucket, ok := bucketFromInput(in.Parameters)
 	if !ok {
 		return next.HandleSerialize(ctx, in)
 	}
 
+	// a bucket being un-vhostable will also force us to use path style
+	usePathStyle := m.UsePathStyle || !awsrulesfn.IsVirtualHostableS3Bucket(bucket, request.URL.Scheme != "https")
+
+	if !smithyhttp.GetHostnameImmutable(ctx) &&
+		!(awsmiddleware.GetRequiresLegacyEndpoints(ctx) && usePathStyle) {
+		return next.HandleSerialize(ctx, in)
+	}
+
 	parsedBucket := awsrulesfn.ParseARN(bucket)
 
 	// disallow ARN buckets except for MRAP arns