[Backport 9.3] fix(esapi): document Response.Body must be closed; fix leaks in examples

_examples/encoding/jsonreader.go

@@ -58,8 +58,8 @@ func main() {
 	if err != nil {
 		log.Fatalf("Error getting response: %s", err)
 	}
-
 	log.Println(res)
+	res.Body.Close()
 
 	query := map[string]interface{}{
 		"query": map[string]interface{}{
@@ -77,6 +77,7 @@ func main() {
 	if err != nil {
 		log.Fatalf("Error getting response: %s", err)
 	}
+	defer res.Body.Close()
 
 	log.Println(res)
 }

_examples/extension/main.go

@@ -96,7 +96,12 @@ func main() {
 
 	// --> Call a custom API
 	//
-	es.Custom.Example()
+	res, err := es.Custom.Example()
+	if err != nil {
+		log.Fatalf("Error calling custom API: %s", err)
+	}
+	defer res.Body.Close()
+	log.Println(res.Status())
 }
 
 func startServer(started chan<- bool) {

_examples/fasthttp/cmd/main.go

@@ -79,6 +79,7 @@ func main() {
 		if err != nil {
 			log.Fatalf("Error getting response: %s", err)
 		}
+		defer res.Body.Close()
 		if res.IsError() {
 			log.Fatalf("Error response: %s", res)
 		}

_examples/security/tls_configure_ca.go

@@ -92,6 +92,7 @@ func main() {
 	if err != nil {
 		log.Fatalf("ERROR: Unable to get response: %s", err)
 	}
+	defer res.Body.Close()
 
 	log.Println(res)
 }

_examples/security/tls_with_ca.go

@@ -75,6 +75,7 @@ func main() {
 	if err != nil {
 		log.Fatalf("ERROR: Unable to get response: %s", err)
 	}
+	defer res.Body.Close()
 
 	log.Println(res)
 }

esapi/esapi.response.go

@@ -31,7 +31,14 @@ import (
 type Response struct {
 	StatusCode int
 	Header     http.Header
-	Body       io.ReadCloser
+	// Body is the response body. Callers must close Body when finished with
+	// it to release the underlying connection back to the pool. Failure to do
+	// so causes connection leaks. The idiomatic pattern is:
+	//
+	//	res, err := es.Info()
+	//	if err != nil { /* handle */ }
+	//	defer res.Body.Close()
+	Body io.ReadCloser
 }
 
 // String returns the response as a string.