feat: Add Caddy placeholders

caddy/module.go

@@ -198,6 +198,12 @@ func (f *FrankenPHPModule) ServeHTTP(w http.ResponseWriter, r *http.Request, _ c
 		return caddyhttp.Error(http.StatusInternalServerError, err)
 	}
 
+	placeholders := fr.Context().Value(frankenphp.PlaceholdersContextKey).(map[string]string)
+
+	for k, v := range placeholders {
+		repl.Set(k, v)
+	}
+
 	return nil
 }
 

context.go

@@ -36,6 +36,9 @@ type frankenPHPContext struct {
 	startedAt time.Time
 }
 
+type placeholdersContextKeyStruct struct{}
+var PlaceholdersContextKey = placeholdersContextKeyStruct{}
+
 // fromContext extracts the frankenPHPContext from a context.
 func fromContext(ctx context.Context) (fctx *frankenPHPContext, ok bool) {
 	fctx, ok = ctx.Value(contextKey).(*frankenPHPContext)
@@ -80,8 +83,11 @@ func NewRequestWithContext(r *http.Request, opts ...RequestOption) (*http.Reques
 	}
 
 	c := context.WithValue(r.Context(), contextKey, fc)
+	c = context.WithValue(c, PlaceholdersContextKey, make(map[string]string))
+	r = r.WithContext(c)
+	fc.request = r
 
-	return r.WithContext(c), nil
+	return r, nil
 }
 
 // newDummyContext creates a fake context from a request path

docs/config.md

@@ -206,6 +206,28 @@ where the FrankenPHP process was started. You can instead also specify one or mo
 
 The file watcher is based on [e-dant/watcher](https://github.com/e-dant/watcher).
 
+### Placeholders
+
+You can set Caddy placeholders from your PHP code using the `frankenphp_set_caddy_placeholder(string $key, string $value)` function.
+These placeholders can then be used in Caddy directives like `log_append`.
+
+Example usage:
+
+```php
+frankenphp_set_caddy_placeholder('frankenphp.custom_placeholder', 'Look at my placeholder!');
+```
+
+```caddyfile
+http:// {
+	log
+	route {
+		# ...
+
+		log_append my_placeholder {frankenphp.custom_placeholder}
+	}
+}
+```
+
 ## Matching the worker to a path
 
 In traditional PHP applications, scripts are always placed in the public directory.

frankenphp.c

@@ -342,6 +342,18 @@ PHP_FUNCTION(frankenphp_getenv) {
   }
 } /* }}} */
 
+/* {{{ Set a placeholder on the current Caddy request */
+PHP_FUNCTION(frankenphp_set_caddy_placeholder) {
+  zend_string *key, *value;
+
+  ZEND_PARSE_PARAMETERS_START(2, 2)
+  Z_PARAM_STR(key)
+  Z_PARAM_STR(value)
+  ZEND_PARSE_PARAMETERS_END();
+
+  go_set_caddy_placeholder(thread_index, ZSTR_VAL(key), ZSTR_VAL(value));
+} /* }}} */
+
 /* {{{ Fetch all HTTP request headers */
 PHP_FUNCTION(frankenphp_request_headers) {
   ZEND_PARSE_PARAMETERS_NONE();

frankenphp.go

@@ -565,6 +565,21 @@ func go_log(message *C.char, level C.int) {
 	}
 }
 
+//export go_set_caddy_placeholder
+func go_set_caddy_placeholder(threadIndex C.uintptr_t, key *C.char, value *C.char) {
+	fc := phpThreads[threadIndex].getRequestContext()
+
+	placeholders, _ := fc.request.Context().Value(PlaceholdersContextKey).(map[string]string)
+
+	if placeholders == nil {
+		logger.LogAttrs(context.Background(), slog.LevelDebug, "frankenphp_set_caddy_placeholder() called in non-HTTP context", slog.String("worker", fc.scriptFilename))
+
+		return
+	}
+
+	placeholders[C.GoString(key)] = C.GoString(value)
+}
+
 //export go_is_context_done
 func go_is_context_done(threadIndex C.uintptr_t) C.bool {
 	return C.bool(phpThreads[threadIndex].getRequestContext().isDone)

frankenphp.h

@@ -56,6 +56,9 @@ int frankenphp_execute_script(char *file_name);
 int frankenphp_execute_script_cli(char *script, int argc, char **argv,
                                   bool eval);
 
+void frankenphp_set_caddy_placeholder(uintptr_t thread_index, zend_string *key,
+                                      zend_string *value);
+
 void frankenphp_register_variables_from_request_info(
     zval *track_vars_array, zend_string *content_type,
     zend_string *path_translated, zend_string *query_string,

frankenphp.stub.php

@@ -32,3 +32,4 @@ function frankenphp_response_headers(): array|bool {}
  */
 function apache_response_headers(): array|bool {}
 
+function frankenphp_set_caddy_placeholder(string $key, string $value): void {}

frankenphp_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 05ebde17137c559e891362fba6524fad1e0a2dfe */
+ * Stub hash: c5318079b1c5629258a1f4b682c7aaf327588b71 */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_frankenphp_handle_request, 0, 1,
                                         _IS_BOOL, 0)
@@ -30,11 +30,18 @@ ZEND_END_ARG_INFO()
 
 #define arginfo_apache_response_headers arginfo_frankenphp_response_headers
 
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(
+    arginfo_frankenphp_set_caddy_placeholder, 0, 2, IS_VOID, 0)
+ZEND_ARG_TYPE_INFO(0, key, IS_STRING, 0)
+ZEND_ARG_TYPE_INFO(0, value, IS_STRING, 0)
+ZEND_END_ARG_INFO()
+
 ZEND_FUNCTION(frankenphp_handle_request);
 ZEND_FUNCTION(headers_send);
 ZEND_FUNCTION(frankenphp_finish_request);
 ZEND_FUNCTION(frankenphp_request_headers);
 ZEND_FUNCTION(frankenphp_response_headers);
+ZEND_FUNCTION(frankenphp_set_caddy_placeholder);
 
 // clang-format off
 static const zend_function_entry ext_functions[] = {
@@ -47,6 +54,7 @@ static const zend_function_entry ext_functions[] = {
   ZEND_FALIAS(getallheaders, frankenphp_request_headers, arginfo_getallheaders)
   ZEND_FE(frankenphp_response_headers, arginfo_frankenphp_response_headers)
   ZEND_FALIAS(apache_response_headers, frankenphp_response_headers, arginfo_apache_response_headers)
+  ZEND_FE(frankenphp_set_caddy_placeholder, arginfo_frankenphp_set_caddy_placeholder)
   ZEND_FE_END
 };
 // clang-format on