MINOR: log: Save alerts and warnings emitted during HAProxy startup

Because we can't always display the standard error messages when HAProxy is
started, all alerts and warnings emitted during the startup will now be saved in
a buffer. It can also be handy to store these messages just in case you
missed something during the startup

To implement this feature, Alert and Warning functions now relies on
display_message. The difference is just on conditions to call this function and
it remains unchanged. In display_message, if MODE_STARTING flag is set, we save
the message.

diff --git a/src/log.c b/src/log.c
index 2af9050a9c0c91f78925ce9343f95b0b4ea09324..ff1ab9a8163e9350304ee222c45a040daf9be3a5 100644 (file)
--- a/src/log.c
+++ b/src/log.c
@@ -225,6 +225,10 @@ char *logline = NULL;
  */
 char *logline_rfc5424 = NULL;
 
+/* A global buffer used to store all startup alerts/warnings. It will then be
+ * retrieve on the CLI. */
+static char *startup_logs = NULL;
+
 struct logformat_var_args {
        char *name;
        int mask;
@@ -664,6 +668,29 @@ int parse_logformat_string(const char *fmt, struct proxy *curproxy, struct list
        return 1;
 }
 
+/* Generic function to display messages prefixed by a label */
+static void print_message(const char *label, const char *fmt, va_list argp)
+{
+       struct tm tm;
+       char *head, *msg;
+
+       head = msg = NULL;
+
+       get_localtime(date.tv_sec, &tm);
+       memprintf(&head, "[%s] %03d/%02d%02d%02d (%d) : ",
+                 label, tm.tm_yday, tm.tm_hour, tm.tm_min, tm.tm_sec, (int)getpid());
+       memvprintf(&msg, fmt, argp);
+
+       if (global.mode & MODE_STARTING)
+               memprintf(&startup_logs, "%s%s%s", (startup_logs ? startup_logs : ""), head, msg);
+
+       fprintf(stderr, "%s%s", head, msg);
+       fflush(stderr);
+
+       free(head);
+       free(msg);
+}
+
 /*
  * Displays the message on stderr with the date and pid. Overrides the quiet
  * mode during startup.
@@ -671,16 +698,10 @@ int parse_logformat_string(const char *fmt, struct proxy *curproxy, struct list
 void Alert(const char *fmt, ...)
 {
        va_list argp;
-       struct tm tm;
 
        if (!(global.mode & MODE_QUIET) || (global.mode & (MODE_VERBOSE | MODE_STARTING))) {
                va_start(argp, fmt);
-
-               get_localtime(date.tv_sec, &tm);
-               fprintf(stderr, "[ALERT] %03d/%02d%02d%02d (%d) : ",
-                       tm.tm_yday, tm.tm_hour, tm.tm_min, tm.tm_sec, (int)getpid());
-               vfprintf(stderr, fmt, argp);
-               fflush(stderr);
+               print_message("ALERT", fmt, argp);
                va_end(argp);
        }
 }
@@ -692,16 +713,10 @@ void Alert(const char *fmt, ...)
 void Warning(const char *fmt, ...)
 {
        va_list argp;
-       struct tm tm;
 
        if (!(global.mode & MODE_QUIET) || (global.mode & MODE_VERBOSE)) {
                va_start(argp, fmt);
-
-               get_localtime(date.tv_sec, &tm);
-               fprintf(stderr, "[WARNING] %03d/%02d%02d%02d (%d) : ",
-                       tm.tm_yday, tm.tm_hour, tm.tm_min, tm.tm_sec, (int)getpid());
-               vfprintf(stderr, fmt, argp);
-               fflush(stderr);
+               print_message("WARNING", fmt, argp);
                va_end(argp);
        }
 }
@@ -1343,10 +1358,12 @@ void deinit_log_buffers()
        free(logheader_rfc5424);
        free(logline);
        free(logline_rfc5424);
+       free(startup_logs);
        logheader         = NULL;
        logheader_rfc5424 = NULL;
        logline           = NULL;
        logline_rfc5424   = NULL;
+       startup_logs      = NULL;
 }
 
 /* Builds a log line in <dst> based on <list_format>, and stops before reaching