Fix race condition in endpoint discovery

CHANGELOG_PENDING.md

@@ -3,3 +3,4 @@
 ### SDK Enhancements
 
 ### SDK Bugs
+* `aws/crr`: Fixed a race condition that caused concurrent calls relying on endpoint discovery to share the same `url.URL` reference in their operation's `http.Request`.

aws/crr/endpoint.go

@@ -60,6 +60,8 @@ func (e *Endpoint) GetValidAddress() (WeightedAddress, bool) {
 			continue
 		}
 
+		we.URL = cloneURL(we.URL)
+
 		return we, true
 	}
 
@@ -97,3 +99,16 @@ func BuildEndpointKey(params map[string]*string) string {
 
 	return strings.Join(values, ".")
 }
+
+func cloneURL(u *url.URL) (clone *url.URL) {
+	clone = &url.URL{}
+
+	*clone = *u
+
+	if u.User != nil {
+		user := *u.User
+		clone.User = &user
+	}
+
+	return clone
+}

aws/crr/endpoint_test.go

@@ -0,0 +1,87 @@
+//go:build go1.16
+// +build go1.16
+
+package crr
+
+import (
+	"net/url"
+	"reflect"
+	"strconv"
+	"testing"
+)
+
+func Test_cloneURL(t *testing.T) {
+	tests := []struct {
+		value     *url.URL
+		wantClone *url.URL
+	}{
+		{
+			value: &url.URL{
+				Scheme:      "https",
+				Opaque:      "foo",
+				User:        nil,
+				Host:        "amazonaws.com",
+				Path:        "/",
+				RawPath:     "/",
+				ForceQuery:  true,
+				RawQuery:    "thing=value",
+				Fragment:    "1234",
+				RawFragment: "1234",
+			},
+			wantClone: &url.URL{
+				Scheme:      "https",
+				Opaque:      "foo",
+				User:        nil,
+				Host:        "amazonaws.com",
+				Path:        "/",
+				RawPath:     "/",
+				ForceQuery:  true,
+				RawQuery:    "thing=value",
+				Fragment:    "1234",
+				RawFragment: "1234",
+			},
+		},
+		{
+			value: &url.URL{
+				Scheme:      "https",
+				Opaque:      "foo",
+				User:        url.UserPassword("NOT", "VALID"),
+				Host:        "amazonaws.com",
+				Path:        "/",
+				RawPath:     "/",
+				ForceQuery:  true,
+				RawQuery:    "thing=value",
+				Fragment:    "1234",
+				RawFragment: "1234",
+			},
+			wantClone: &url.URL{
+				Scheme:      "https",
+				Opaque:      "foo",
+				User:        url.UserPassword("NOT", "VALID"),
+				Host:        "amazonaws.com",
+				Path:        "/",
+				RawPath:     "/",
+				ForceQuery:  true,
+				RawQuery:    "thing=value",
+				Fragment:    "1234",
+				RawFragment: "1234",
+			},
+		},
+	}
+	for i, tt := range tests {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			gotClone := cloneURL(tt.value)
+			if gotClone == tt.value {
+				t.Errorf("expct clone URL to not be same pointer address")
+			}
+			if tt.value.User != nil {
+				if tt.value.User == gotClone.User {
+					t.Errorf("expct cloned Userinfo to not be same pointer address")
+				}
+			}
+			if !reflect.DeepEqual(gotClone, tt.wantClone) {
+				t.Errorf("cloneURL() = %v, want %v", gotClone, tt.wantClone)
+			}
+		})
+	}
+}