Merge pull request #52 from worldia/feat/filter-headers

feat(Common): Sanitize headers before adding them to span attributes

src/Http/TracedResponse.php

@@ -51,6 +51,29 @@ public function getHeaders(bool $throw = true): array
         return $this->response->getHeaders($throw);
     }
 
+    private function toReadableHeaderValue(mixed $value): string
+    {
+        if (null === $value) {
+            return 'null';
+        } elseif (\is_array($value)) {
+            return implode(', ', array_map([$this, __FUNCTION__], $value));
+        } elseif (\is_scalar($value)) {
+            if (\is_bool($value)) {
+                return true === $value ? 'true' : 'false';
+            }
+
+            return (string) $value;
+        } elseif (\is_object($value)) {
+            if (method_exists($value, '__toString')) {
+                return (string) $value;
+            }
+
+            return '(object)#'.$value::class;
+        }
+
+        return \gettype($value);
+    }
+
     public function getContent(bool $throw = true): string
     {
         try {
@@ -150,8 +173,15 @@ protected function endTracing(): void
 
         try {
             if (\in_array('response.headers', $info['user_data']['span_attributes'] ?? [])) {
-                $this->span->setAttribute('response.headers', $this->getHeaders(false));
+                $headers = [];
+                $raw = $this->getHeaders(false);
+                foreach ($raw as $header => $value) {
+                    $headers[$header] = $this->toReadableHeaderValue($value);
+                }
+
+                $this->span->setAttribute('response.headers', $headers);
             }
+
             if (\in_array('response.body', $info['user_data']['span_attributes'] ?? [])) {
                 if (empty($this->content) && \is_resource($this->stream)) {
                     $this->content = stream_get_contents($this->stream) ?: null;