From d2adbc5c0014d2b7de556e837a508ba999b08f51 Mon Sep 17 00:00:00 2001
From: Carlos Alexandro Becker <caarlos0@users.noreply.github.com>
Date: Wed, 21 Aug 2024 02:07:04 -0300
Subject: [PATCH] aws/all: Add a "hostname_immutable" URL parameter for AWS v2
 URLs with endpoints

---
 aws/aws.go      | 31 ++++++++++++++++++++++---------
 aws/aws_test.go | 37 +++++++++++++++++++++++++++++++++----
 2 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/aws/aws.go b/aws/aws.go
index 21d4ec5afa..0f2d9c61ff 100644
--- a/aws/aws.go
+++ b/aws/aws.go
@@ -177,23 +177,24 @@ func NewDefaultV2Config(ctx context.Context) (awsv2.Config, error) {
 //   - region: The AWS region for requests; sets WithRegion.
 //   - profile: The shared config profile to use; sets SharedConfigProfile.
 //   - endpoint: The AWS service endpoint to send HTTP request.
+//   - hostname_immutable: Make the hostname immutable, only works if endpoint is also set.
 func V2ConfigFromURLParams(ctx context.Context, q url.Values) (awsv2.Config, error) {
+	var endpoint string
+	var hostnameImmutable bool
 	var opts []func(*awsv2cfg.LoadOptions) error
 	for param, values := range q {
 		value := values[0]
 		switch param {
+		case "hostname_immutable":
+			var err error
+			hostnameImmutable, err = strconv.ParseBool(value)
+			if err != nil {
+				return awsv2.Config{}, fmt.Errorf("invalid value for hostname_immutable: %w", err)
+			}
 		case "region":
 			opts = append(opts, awsv2cfg.WithRegion(value))
 		case "endpoint":
-			customResolver := awsv2.EndpointResolverWithOptionsFunc(
-				func(service, region string, options ...interface{}) (awsv2.Endpoint, error) {
-					return awsv2.Endpoint{
-						PartitionID:   "aws",
-						URL:           value,
-						SigningRegion: region,
-					}, nil
-				})
-			opts = append(opts, awsv2cfg.WithEndpointResolverWithOptions(customResolver))
+			endpoint = value
 		case "profile":
 			opts = append(opts, awsv2cfg.WithSharedConfigProfile(value))
 		case "awssdk":
@@ -202,5 +203,17 @@ func V2ConfigFromURLParams(ctx context.Context, q url.Values) (awsv2.Config, err
 			return awsv2.Config{}, fmt.Errorf("unknown query parameter %q", param)
 		}
 	}
+	if endpoint != "" {
+		customResolver := awsv2.EndpointResolverWithOptionsFunc(
+			func(service, region string, options ...interface{}) (awsv2.Endpoint, error) {
+				return awsv2.Endpoint{
+					PartitionID:       "aws",
+					URL:               endpoint,
+					SigningRegion:     region,
+					HostnameImmutable: hostnameImmutable,
+				}, nil
+			})
+		opts = append(opts, awsv2cfg.WithEndpointResolverWithOptions(customResolver))
+	}
 	return awsv2cfg.LoadDefaultConfig(ctx, opts...)
 }
diff --git a/aws/aws_test.go b/aws/aws_test.go
index 5d04dae75d..29dbee1ae5 100644
--- a/aws/aws_test.go
+++ b/aws/aws_test.go
@@ -17,8 +17,10 @@ package aws_test
 import (
 	"context"
 	"net/url"
+	"reflect"
 	"testing"
 
+	awsv2 "github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/google/go-cmp/cmp"
 	gcaws "gocloud.dev/aws"
@@ -147,12 +149,16 @@ func TestUseV2(t *testing.T) {
 }
 
 func TestV2ConfigFromURLParams(t *testing.T) {
+	const service = "s3"
+	const region = "us-east-1"
+	const partitionID = "aws"
 	ctx := context.Background()
 	tests := []struct {
-		name       string
-		query      url.Values
-		wantRegion string
-		wantErr    bool
+		name         string
+		query        url.Values
+		wantRegion   string
+		wantErr      bool
+		wantEndpoint *awsv2.Endpoint
 	}{
 		{
 			name:  "No overrides",
@@ -168,6 +174,16 @@ func TestV2ConfigFromURLParams(t *testing.T) {
 			query:      url.Values{"region": {"my_region"}},
 			wantRegion: "my_region",
 		},
+		{
+			name:  "Endpoint and hostname immutable",
+			query: url.Values{"endpoint": {"foo"}, "hostname_immutable": {"true"}},
+			wantEndpoint: &awsv2.Endpoint{
+				PartitionID:       partitionID,
+				SigningRegion:     region,
+				URL:               "foo",
+				HostnameImmutable: true,
+			},
+		},
 		// Can't test "profile", since AWS validates that the profile exists.
 	}
 
@@ -184,6 +200,19 @@ func TestV2ConfigFromURLParams(t *testing.T) {
 			if test.wantRegion != "" && got.Region != test.wantRegion {
 				t.Errorf("got region %q, want %q", got.Region, test.wantRegion)
 			}
+
+			if test.wantEndpoint != nil {
+				if got.EndpointResolverWithOptions == nil {
+					t.Fatalf("expected an EndpointResolverWithOptions, got nil")
+				}
+				gotE, err := got.EndpointResolverWithOptions.ResolveEndpoint(service, region)
+				if err != nil {
+					return
+				}
+				if !reflect.DeepEqual(gotE, *test.wantEndpoint) {
+					t.Errorf("got endpoint %+v, want %+v", gotE, *test.wantEndpoint)
+				}
+			}
 		})
 	}
 }