implement dummy /metrics handler

src/exchange/Makefile.am

@@ -97,6 +97,7 @@ taler_exchange_httpd_SOURCES = \
   taler-exchange-httpd_management_wire_disable.c \
   taler-exchange-httpd_management_wire_fees.c \
   taler-exchange-httpd_melt.c taler-exchange-httpd_melt.h \
+  taler-exchange-httpd_metrics.c taler-exchange-httpd_metrics.h \
   taler-exchange-httpd_mhd.c taler-exchange-httpd_mhd.h \
   taler-exchange-httpd_recoup.c taler-exchange-httpd_recoup.h \
   taler-exchange-httpd_refreshes_reveal.c taler-exchange-httpd_refreshes_reveal.h \

src/exchange/taler-exchange-httpd.c

@@ -39,6 +39,7 @@
 #include "taler-exchange-httpd_link.h"
 #include "taler-exchange-httpd_management.h"
 #include "taler-exchange-httpd_melt.h"
+#include "taler-exchange-httpd_metrics.h"
 #include "taler-exchange-httpd_mhd.h"
 #include "taler-exchange-httpd_recoup.h"
 #include "taler-exchange-httpd_refreshes_reveal.h"
@@ -849,6 +850,12 @@ handle_mhd_request (void *cls,
       .method = MHD_HTTP_METHOD_GET,
       .handler.get = &handler_seed
     },
+    /* Performance metrics */
+    {
+      .url = "metrics",
+      .method = MHD_HTTP_METHOD_GET,
+      .handler.get = &TEH_handler_metrics
+    },
     /* Terms of service */
     {
       .url = "terms",

src/exchange/taler-exchange-httpd_metrics.c

@@ -0,0 +1,43 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2015-2021 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU Affero General Public License as published by the Free Software
+  Foundation; either version 3, or (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+  A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_metrics.c
+ * @brief Handle /metrics requests
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_json_lib.h>
+#include "taler_dbevents.h"
+#include "taler-exchange-httpd_responses.h"
+#include "taler-exchange-httpd_keys.h"
+#include "taler-exchange-httpd_metrics.h"
+#include "taler_json_lib.h"
+#include "taler_mhd_lib.h"
+#include <jansson.h>
+
+
+MHD_RESULT
+TEH_handler_metrics (struct TEH_RequestContext *rc,
+                     const char *const args[])
+{
+  (void) args;
+  return TALER_MHD_reply_json (rc->connection,
+                               json_pack ("{}"),
+                               MHD_HTTP_NO_CONTENT);
+}
+
+
+/* end of taler-exchange-httpd_metrics.c */

src/exchange/taler-exchange-httpd_metrics.h

@@ -0,0 +1,41 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014--2021 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU Affero General Public License as published by the Free Software
+  Foundation; either version 3, or (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+  A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_metrics.h
+ * @brief Handle /metrics requests
+ * @author Christian Grothoff
+ */
+#ifndef TALER_EXCHANGE_HTTPD_METRICS_H
+#define TALER_EXCHANGE_HTTPD_METRICS_H
+
+#include <gnunet/gnunet_util_lib.h>
+#include <microhttpd.h>
+#include "taler-exchange-httpd.h"
+
+
+/**
+ * Handle a "/metrics" request.
+ *
+ * @param rc request context
+ * @param args array of additional options (must be empty for this function)
+ * @return MHD result code
+ */
+MHD_RESULT
+TEH_handler_metrics (struct TEH_RequestContext *rc,
+                     const char *const args[]);
+
+
+#endif