MINOR: trace/cli: add "show trace" to report trace state and statistics

The new "show trace" CLI command lists available trace sources and
indicates their status, their sink, and number of dropped packets.
When "show trace <source>" is used, the list of known events is
also listed with their status per action (report/start/stop/pause).

diff --git a/src/trace.c b/src/trace.c
index 6d40fec638be26ed0d9bac3178b107b8fd52653c..8691b65f157cd7911ecc0614b2f288b4087253b4 100644 (file)
--- a/src/trace.c
+++ b/src/trace.c
@@ -239,8 +239,63 @@ static int cli_parse_trace(char **args, char *payload, struct appctx *appctx, vo
        return 0;
 }
 
+/* parse the command, returns 1 if a message is returned, otherwise zero */
+static int cli_parse_show_trace(char **args, char *payload, struct appctx *appctx, void *private)
+{
+       struct trace_source *src;
+       const struct sink *sink;
+       int i;
+
+       args++; // make args[1] the 1st arg
+
+       if (!*args[1]) {
+               /* no arg => report the list of supported sources */
+               chunk_printf(&trash,
+                            "Supported trace sources and states (.=stopped, w=waiting, R=running) :\n"
+                            );
+
+               list_for_each_entry(src, &trace_sources, source_link) {
+                       sink = src->sink;
+                       chunk_appendf(&trash, " [%c] %-10s -> %s [drp %u]  [%s]\n",
+                                     trace_state_char(src->state), src->name.ptr,
+                                     sink ? sink->name : "none",
+                                     sink ? sink->ctx.dropped : 0,
+                                     src->desc);
+               }
+
+               trash.area[trash.data] = 0;
+               return cli_msg(appctx, LOG_INFO, trash.area);
+       }
+
+       if (!cli_has_level(appctx, ACCESS_LVL_OPER))
+               return 1;
+
+       src = trace_find_source(args[1]);
+       if (!src)
+               return cli_err(appctx, "No such trace source");
+
+       sink = src->sink;
+       chunk_printf(&trash, "Trace status for %s:\n", src->name.ptr);
+       chunk_appendf(&trash, "  - sink: %s [%u dropped]\n",
+                     sink ? sink->name : "none", sink ? sink->ctx.dropped : 0);
+
+       chunk_appendf(&trash, "  - event name :     report    start    stop    pause\n");
+       for (i = 0; src->known_events && src->known_events[i].mask; i++) {
+               chunk_appendf(&trash, "    %-10s :        %c        %c        %c       %c\n",
+                             src->known_events[i].name,
+                             trace_event_char(src->report_events, src->known_events[i].mask),
+                             trace_event_char(src->start_events, src->known_events[i].mask),
+                             trace_event_char(src->stop_events, src->known_events[i].mask),
+                             trace_event_char(src->pause_events, src->known_events[i].mask));
+       }
+
+       trash.area[trash.data] = 0;
+       return cli_msg(appctx, LOG_WARNING, trash.area);
+}
+
 static struct cli_kw_list cli_kws = {{ },{
        { { "trace", NULL }, "trace <module> [cmd [args...]] : manage live tracing", cli_parse_trace, NULL, NULL },
+       { { "show", "trace", NULL }, "show trace [<module>] : show live tracing state", cli_parse_show_trace, NULL, NULL },
        {{},}
 }};