From b380a0df3c0ff59385cf59c6a50de9392bdd8d34 Mon Sep 17 00:00:00 2001
From: Ago Allikmaa <ago@allikmaa.eu>
Date: Wed, 28 Feb 2024 09:13:17 +0200
Subject: [PATCH] Extract response headers for Guzzle, HTTPlug Async (#241)

---
 src/GuzzleInstrumentation.php | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/GuzzleInstrumentation.php b/src/GuzzleInstrumentation.php
index 523f90e..609fb9c 100644
--- a/src/GuzzleInstrumentation.php
+++ b/src/GuzzleInstrumentation.php
@@ -100,6 +100,13 @@ public static function register(): void
                         $span->setAttribute(TraceAttributes::HTTP_RESPONSE_STATUS_CODE, $response->getStatusCode());
                         $span->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $response->getProtocolVersion());
                         $span->setAttribute(TraceAttributes::HTTP_RESPONSE_BODY_SIZE, $response->getHeaderLine('Content-Length'));
+
+                        foreach ((array) (get_cfg_var('otel.instrumentation.http.response_headers') ?: []) as $header) {
+                            if ($response->hasHeader($header)) {
+                                /** @psalm-suppress ArgumentTypeCoercion */
+                                $span->setAttribute(sprintf('http.response.header.%s', strtolower($header)), $response->getHeader($header));
+                            }
+                        }
                         if ($response->getStatusCode() >= 400 && $response->getStatusCode() < 600) {
                             $span->setStatus(StatusCode::STATUS_ERROR);
                         }