[Fix] Use base name for OpenMetrics counter TYPE declarations

OpenMetrics specification requires counter metrics to have _total suffix
on the metric value, but HELP and TYPE declarations must use the base
name without the suffix.

Before: # TYPE rspamd_scanned_total counter
After:  # TYPE rspamd_scanned counter

This fixes parser rejections due to name clashes when metrics scrapers
see _total in the TYPE line and append another _total.

diff --git a/src/libserver/worker_util.h b/src/libserver/worker_util.h
index 09d8018dbeeecbc9bed1203ca61eb0402056418e..de80b6a37bf3ada7d3da7f46811a0bba160558c9 100644 (file)
--- a/src/libserver/worker_util.h
+++ b/src/libserver/worker_util.h
@@ -336,8 +336,29 @@ rspamd_metrics_add_integer(rspamd_fstring_t **output,
                                                   const char *description,
                                                   const char *ucl_key)
 {
-       rspamd_printf_fstring(output, "# HELP %s %s\n", name, description);
-       rspamd_printf_fstring(output, "# TYPE %s %s\n", name, type);
+       /*
+        * OpenMetrics requires counters to have _total suffix on the metric value,
+        * but the TYPE declaration uses the base name (without _total).
+        * E.g.: # TYPE rspamd_scanned counter
+        *       rspamd_scanned_total 123
+        */
+       size_t name_len = strlen(name);
+       const char *total_suffix = "_total";
+       size_t suffix_len = 6;
+       gboolean is_counter_with_total = (strcmp(type, "counter") == 0 &&
+                                                                         name_len > suffix_len &&
+                                                                         strcmp(name + name_len - suffix_len, total_suffix) == 0);
+
+       if (is_counter_with_total) {
+               /* Strip _total for HELP and TYPE lines */
+               size_t base_len = name_len - suffix_len;
+               rspamd_printf_fstring(output, "# HELP %.*s %s\n", (int) base_len, name, description);
+               rspamd_printf_fstring(output, "# TYPE %.*s %s\n", (int) base_len, name, type);
+       }
+       else {
+               rspamd_printf_fstring(output, "# HELP %s %s\n", name, description);
+               rspamd_printf_fstring(output, "# TYPE %s %s\n", name, type);
+       }
        rspamd_printf_fstring(output, "%s %L\n", name,
                                                  ucl_object_toint(ucl_object_lookup(top, ucl_key)));
 }