core: notify plugins when a log line is emitted.

Currently make a plugin that do reportings of logs on
a services like graphana is not possible. So this commit
include the possibility to write a plugin that do the report
of this analisys.

Changelog-Added: core: notify plugins when a log line is emitted.
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

lightningd/log.c

@@ -540,6 +540,13 @@ static void maybe_print(struct logger *log, const struct log_entry *l)
 			     log->log_book->log_files);
 }
 
+static void maybe_notify_log(struct logger *log,
+			     const struct log_entry *l)
+{
+	if (l->level >= log->print_level)
+		notify_log(log->log_book->ld, l);
+}
+
 void logv(struct logger *log, enum log_level level,
 	  const struct node_id *node_id,
 	  bool call_notifier,
@@ -561,6 +568,7 @@ void logv(struct logger *log, enum log_level level,
 			l->log[i] = '?';
 
 	maybe_print(log, l);
+	maybe_notify_log(log, l);
 
 	add_entry(log, &l);
 

lightningd/notification.c

@@ -3,6 +3,7 @@
 #include <common/type_to_string.h>
 #include <lightningd/channel.h>
 #include <lightningd/coin_mvts.h>
+#include <lightningd/log.h>
 #include <lightningd/notification.h>
 
 static struct notification *find_notification_by_topic(const char* topic)
@@ -122,29 +123,35 @@ void notify_disconnect(struct lightningd *ld, struct node_id *nodeid)
 
 /*'warning' is based on LOG_UNUSUAL/LOG_BROKEN level log
  *(in plugin module, they're 'warn'/'error' level). */
-static void warning_notification_serialize(struct json_stream *stream,
+static void log_notification_serialize(struct json_stream *stream,
 					   struct log_entry *l)
 {
-	json_object_start(stream, "warning");
-	/* Choose "BROKEN"/"UNUSUAL" to keep consistent with the habit
-	 * of plugin. But this may confuses the users who want to 'getlog'
-	 * with the level indicated by notifications. It is the duty of a
-	 * plugin to eliminate this misunderstanding.
-	 */
-	json_add_string(stream, "level",
-			l->level == LOG_BROKEN ? "error"
-			: "warn");
+	if (l->level >= LOG_UNUSUAL)
+		json_object_start(stream, "warning");
+	else
+		json_object_start(stream, NULL);
+	if (l->level >= LOG_UNUSUAL)
+		/* Choose "BROKEN"/"UNUSUAL" to keep consistent with the habit
+		 * of plugin. But this may confuses the users who want to 'getlog'
+		 * with the level indicated by notifications. It is the duty of a
+		 * plugin to eliminate this misunderstanding.
+		 */
+		json_add_string(stream, "level",
+				l->level == LOG_BROKEN ? "error"
+				: "warn");
+	else
+		json_add_string(stream, "level", log_level_name(l->level));
 	/* unsuaul/broken event is rare, plugin pay more attentions on
 	 * the absolute time, like when channels failed. */
 	json_add_timestr(stream, "time", l->time.ts);
 	json_add_timeiso(stream, "timestamp", l->time);
 	json_add_string(stream, "source", l->prefix->prefix);
 	json_add_string(stream, "log", l->log);
-	json_object_end(stream); /* .warning */
+	json_object_end(stream);
 }
 
 REGISTER_NOTIFICATION(warning,
-		      warning_notification_serialize);
+		      log_notification_serialize);
 
 void notify_warning(struct lightningd *ld, struct log_entry *l)
 {
@@ -746,3 +753,17 @@ bool notify_plugin_shutdown(struct lightningd *ld, struct plugin *p)
 	jsonrpc_notification_end(n);
 	return plugin_single_notify(p, take(n));
 }
+
+REGISTER_NOTIFICATION(log, log_notification_serialize);
+
+void notify_log(struct lightningd *ld, const struct log_entry *l)
+{
+	void (*serialize)(struct json_stream *,
+			  const struct log_entry *) = log_notification_gen.serialize;
+
+	struct jsonrpc_notification *n =
+		jsonrpc_notification_start(NULL, log_notification_gen.topic);
+	serialize(n->stream, l);
+	jsonrpc_notification_end(n);
+	plugins_notify(ld->plugins, take(n));
+}

lightningd/notification.h

@@ -1,6 +1,8 @@
 #ifndef LIGHTNING_LIGHTNINGD_NOTIFICATION_H
 #define LIGHTNING_LIGHTNINGD_NOTIFICATION_H
 #include "config.h"
+#include "lightningd/lightningd.h"
+#include "lightningd/log.h"
 #include <common/coin_mvt.h>
 #include <lightningd/chaintopology.h>
 #include <lightningd/pay.h>
@@ -106,4 +108,6 @@ void notify_channel_open_failed(struct lightningd *ld,
 
 /* Tell this plugin to shutdown: returns true if it was subscribed. */
 bool notify_plugin_shutdown(struct lightningd *ld, struct plugin *p);
+/* Inform the plugin when a log line is emitted */
+void notify_log(struct lightningd *ld, const struct log_entry *l);
 #endif /* LIGHTNING_LIGHTNINGD_NOTIFICATION_H */

lightningd/test/run-invoice-select-inchan.c

@@ -237,19 +237,10 @@ bool feature_negotiated(const struct feature_set *our_features UNNEEDED,
 /* Generated stub for featurebits_or */
 u8 *featurebits_or(const tal_t *ctx UNNEEDED, const u8 *f1 TAKES UNNEEDED, const u8 *f2 TAKES UNNEEDED)
 { fprintf(stderr, "featurebits_or called!\n"); abort(); }
-/* Generated stub for find_channel_by_alias */
-struct channel *find_channel_by_alias(const struct peer *peer UNNEEDED,
-				      const struct short_channel_id *alias UNNEEDED,
-				      enum side side UNNEEDED)
-{ fprintf(stderr, "find_channel_by_alias called!\n"); abort(); }
 /* Generated stub for find_channel_by_id */
 struct channel *find_channel_by_id(const struct peer *peer UNNEEDED,
 				   const struct channel_id *cid UNNEEDED)
 { fprintf(stderr, "find_channel_by_id called!\n"); abort(); }
-/* Generated stub for find_channel_by_scid */
-struct channel *find_channel_by_scid(const struct peer *peer UNNEEDED,
-				     const struct short_channel_id *scid UNNEEDED)
-{ fprintf(stderr, "find_channel_by_scid called!\n"); abort(); }
 /* Generated stub for find_plugin_for_command */
 struct plugin *find_plugin_for_command(struct lightningd *ld UNNEEDED,
 				       const char *cmd_name UNNEEDED)

lightningd/test/run-log-pruning.c

@@ -84,6 +84,9 @@ bool log_level_parse(const char *levelstr UNNEEDED, size_t len UNNEEDED,
 /* Generated stub for node_id_to_hexstr */
 char *node_id_to_hexstr(const tal_t *ctx UNNEEDED, const struct node_id *id UNNEEDED)
 { fprintf(stderr, "node_id_to_hexstr called!\n"); abort(); }
+/* Generated stub for notify_log */
+void notify_log(struct lightningd *ld UNNEEDED, const struct log_entry *l UNNEEDED)
+{ fprintf(stderr, "notify_log called!\n"); abort(); }
 /* Generated stub for notify_warning */
 void notify_warning(struct lightningd *ld UNNEEDED, struct log_entry *l UNNEEDED)
 { fprintf(stderr, "notify_warning called!\n"); abort(); }

lightningd/test/run-log_filter.c

@@ -78,6 +78,9 @@ void json_stream_log_suppress_for_cmd(struct json_stream *js UNNEEDED,
 /* Generated stub for json_stream_success */
 struct json_stream *json_stream_success(struct command *cmd UNNEEDED)
 { fprintf(stderr, "json_stream_success called!\n"); abort(); }
+/* Generated stub for notify_log */
+void notify_log(struct lightningd *ld UNNEEDED, const struct log_entry *l UNNEEDED)
+{ fprintf(stderr, "notify_log called!\n"); abort(); }
 /* Generated stub for notify_warning */
 void notify_warning(struct lightningd *ld UNNEEDED, struct log_entry *l UNNEEDED)
 { fprintf(stderr, "notify_warning called!\n"); abort(); }