feat: introduce new reverse_proxy_cache_control config to allow configuring specific cache control for reverse proxy

Author: 94noni

Resources/doc/reference/configuration/headers.rst

@@ -347,6 +347,39 @@ section:
 
 This example adds the header ``X-Reverse-Proxy-TTL: 3600`` to your responses.
 
+``reverse_proxy_cache_control``
+"""""""""""""""""""""
+
+**type**: ``array``
+
+The map under ``reverse_proxy_cache_control`` goes with ``ttl_header``.
+The names are specified with underscores in yaml, but translated to ``-`` for
+the ``Cache-Control`` header.
+
+You can use the standard cache control directives:
+
+* ``max_age`` time in seconds;
+* ``s_maxage`` time in seconds for proxy caches (also public caches);
+* ``private`` true or false;
+* ``public`` true or false;
+
+.. code-block:: yaml
+
+    # app/config/config.yml
+    fos_http_cache:
+        cache_control:
+            rules:
+                -
+                    headers:
+                        reverse_proxy_cache_control:
+                            max_age: 36000
+                            public: true
+                        cache_control:
+                            no_store: true
+                            private: true
+
+This example adds the header ``X-Reverse-Proxy-TTL: max-age=36000, public`` to your responses.
+
 ``ttl_header``
 --------------
 

src/EventListener/CacheControlListener.php

@@ -116,11 +116,18 @@ public function onKernelResponse(ResponseEvent $event): void
             }
         }
 
-        if (array_key_exists('reverse_proxy_ttl', $options)
-            && null !== $options['reverse_proxy_ttl']
-            && !$response->headers->has($this->ttlHeader)
-        ) {
-            $response->headers->set($this->ttlHeader, $options['reverse_proxy_ttl'], false);
+        if (!$response->headers->has($this->ttlHeader)) {
+            if (!empty($options['reverse_proxy_cache_control'])) {
+                $directives = array_intersect_key($options['reverse_proxy_cache_control'], $this->supportedDirectives);
+                if (!empty($directives)) {
+                    $directives = array_map(function ($key) {return str_replace('_', '-', $key);}, $directives);
+                    $response->headers->set($this->ttlHeader, implode(' ', $directives), false);
+                }
+            }  elseif (array_key_exists('reverse_proxy_ttl', $options)
+                && null !== $options['reverse_proxy_ttl']
+            ) {
+                $response->headers->set($this->ttlHeader, $options['reverse_proxy_ttl'], false);
+            }
         }
 
         if (!empty($options['vary'])) {