Initial QSfera import

Server/vendor/github.com/opensearch-project/opensearch-go/v4/signer/signer.go

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// The OpenSearch Contributors require contributions made to
+// this file be licensed under the Apache-2.0 license or a
+// compatible open source license.
+//
+// Modifications Copyright OpenSearch Contributors. See
+// GitHub history for details.
+
+package signer
+
+import "net/http"
+
+// Signer an interface that will sign http.Request
+type Signer interface {
+	SignRequest(request *http.Request) error
+	OverrideSigningPort(portNumber uint16)
+}