[logger] Support logging with logfmt format

src/conffile.c

@@ -49,6 +49,7 @@ static cfg_opt_t sec_general[] =
     CFG_STR("db_backup_path", NULL, CFGF_NONE),
     CFG_STR("logfile", STATEDIR "/log/" PACKAGE ".log", CFGF_NONE),
     CFG_INT_CB("loglevel", E_LOG, CFGF_NONE, &cb_loglevel),
+    CFG_STR("logformat", "default", CFGF_NONE),
     CFG_STR("admin_password", NULL, CFGF_NONE),
     CFG_INT("websocket_port", 3688, CFGF_NONE),
     CFG_STR("websocket_interface", NULL, CFGF_NONE),

src/logger.c

@@ -60,7 +60,13 @@ static char *logfilename;
 static FILE *logfile;
 static char *labels[] = { "config", "daap", "db", "httpd", "http", "main", "mdns", "misc", "rsp", "scan", "xcode", "event", "remote", "dacp", "ffmpeg", "artwork", "player", "raop", "laudio", "dmap", "dbperf", "spotify", "scrobble", "cache", "mpd", "stream", "cast", "fifo", "lib", "web", "airplay", "rcp" };
 static char *severities[] = { "FATAL", "LOG", "WARN", "INFO", "DEBUG", "SPAM" };
+static char *format_labels[] = { "default", "logfmt" };
 
+enum format {
+  L_FMT_DEFAULT = 0,
+  L_FMT_LOGFMT = 1,
+};
+static enum format format = L_FMT_DEFAULT;
 
 static int
 set_logdomains(char *domains)
@@ -94,6 +100,23 @@ set_logdomains(char *domains)
   return 0;
 }
 
+static int
+format_code_get(const char *label)
+{
+  int i;
+
+  if (!label)
+    return 0;
+
+  for (i = 0; i < ARRAY_SIZE(format_labels); i++)
+    {
+      if (strcmp(label, format_labels[i]) == 0)
+	return i;
+    }
+
+  return 0;
+}
+
 static int
 repeat_count(const char *fmt)
 {
@@ -139,16 +162,34 @@ logger_write_with_label(int severity, int domain, const char *content)
   char thread_nametid[32];
   time_t t;
   struct tm timebuf;
+  char logfmt_msg[1024];
   int ret;
 
   thread_getnametid(thread_nametid, sizeof(thread_nametid));
-
   t = time(NULL);
-  ret = strftime(stamp, sizeof(stamp), "%Y-%m-%d %H:%M:%S", localtime_r(&t, &timebuf));
-  if (ret == 0)
-    stamp[0] = '\0';
 
-  logger_write("[%s] [%5s] [%16s] %8s: %s", stamp, severities[severity], thread_nametid, labels[domain], content);
+  if (format == L_FMT_LOGFMT)
+    {
+      ret = strftime(stamp, sizeof(stamp), "%Y-%m-%dT%H:%M:%S%z", localtime_r(&t, &timebuf));
+      if (ret == 0)
+	stamp[0] = '\0';
+
+      strncpy(logfmt_msg, content, sizeof(logfmt_msg));
+      logfmt_msg[sizeof(logfmt_msg) - 1] = '\0';
+      safe_snreplace(logfmt_msg, sizeof(logfmt_msg), "\n", " ");
+      safe_snreplace(logfmt_msg, sizeof(logfmt_msg), "\"", "\\\"");
+
+      logger_write("time=%s level=%s thread=\"%s\" component=%s msg=\"%s\"\n", stamp, severities[severity], thread_nametid,
+          labels[domain], logfmt_msg);
+    }
+  else
+    {
+      ret = strftime(stamp, sizeof(stamp), "%Y-%m-%d %H:%M:%S", localtime_r(&t, &timebuf));
+      if (ret == 0)
+	stamp[0] = '\0';
+
+      logger_write("[%s] [%5s] [%16s] %8s: %s", stamp, severities[severity], thread_nametid, labels[domain], content);
+    }
 }
 
 static void
@@ -408,7 +449,7 @@ logger_detach(void)
 }
 
 int
-logger_init(char *file, char *domains, int severity)
+logger_init(char *file, char *domains, int severity, char *logformat)
 {
   int ret;
 
@@ -421,6 +462,7 @@ logger_init(char *file, char *domains, int severity)
 
   console = 1;
   threshold = severity;
+  format = format_code_get(logformat);
 
   if (domains)
     {

src/logger.h

@@ -84,7 +84,7 @@ void
 logger_detach(void);
 
 int
-logger_init(char *file, char *domains, int severity);
+logger_init(char *file, char *domains, int severity, char *logformat);
 
 void
 logger_deinit(void);

src/main.c

@@ -495,6 +495,7 @@ main(int argc, char **argv)
   int loglevel = -1;
   char *logdomains = NULL;
   char *logfile = NULL;
+  char *logformat = NULL;
   char *ffid = NULL;
   char *pidfile = PIDFILE;
   char *webroot = WEB_ROOT;
@@ -510,26 +511,26 @@ main(int argc, char **argv)
   int i;
   int ret;
 
-  struct option option_map[] =
+  struct option option_map[] = {
-    {
+    { "ffid",          1, NULL, 'b' },
-      { "ffid",         1, NULL, 'b' },
+    { "debug",         1, NULL, 'd' },
-      { "debug",        1, NULL, 'd' },
+    { "logdomains",    1, NULL, 'D' },
-      { "logdomains",   1, NULL, 'D' },
+    { "foreground",    0, NULL, 'f' },
-      { "foreground",   0, NULL, 'f' },
+    { "config",        1, NULL, 'c' },
-      { "config",       1, NULL, 'c' },
+    { "pidfile",       1, NULL, 'P' },
-      { "pidfile",      1, NULL, 'P' },
+    { "version",       0, NULL, 'v' },
-      { "version",      0, NULL, 'v' },
+    { "webroot",       1, NULL, 'w' },
-      { "webroot",      1, NULL, 'w' },
+    { "sqliteext",     1, NULL, 's' },
-      { "sqliteext",    1, NULL, 's' },
+    { "testrun",       0, NULL, 't' }, // Used for CI, not documented to user
-      { "testrun",      0, NULL, 't' }, // Used for CI, not documented to user
 
-      { "mdns-no-rsp",  0, NULL, 512 },
+    { "mdns-no-rsp",   0, NULL, 512 },
-      { "mdns-no-daap", 0, NULL, 513 },
+    { "mdns-no-daap",  0, NULL, 513 },
-      { "mdns-no-cname",0, NULL, 514 },
+    { "mdns-no-cname", 0, NULL, 514 },
-      { "mdns-no-web",  0, NULL, 515 },
+    { "mdns-no-web",   0, NULL, 515 },
+    { "logformat",     1, NULL, 516 },
 
-      { NULL,           0, NULL, 0 }
+    { NULL,            0, NULL, 0   }
-    };
+  };
 
   while ((option = getopt_long(argc, argv, "D:d:c:P:ftb:vw:s:", option_map, NULL)) != -1)
     {
@@ -551,6 +552,10 @@ main(int argc, char **argv)
 	    mdns_no_web = true;
 	    break;
 
+	  case 516:
+	    logformat = optarg;
+	    break;
+
 	  case 't':
 	    testrun = true;
 	    break;
@@ -603,7 +608,7 @@ main(int argc, char **argv)
 	}
     }
 
-  ret = logger_init(NULL, NULL, (loglevel < 0) ? E_LOG : loglevel);
+  ret = logger_init(NULL, NULL, (loglevel < 0) ? E_LOG : loglevel, NULL);
   if (ret != 0)
     {
       fprintf(stderr, "Could not initialize log facility\n");
@@ -625,10 +630,11 @@ main(int argc, char **argv)
   /* Reinit log facility with configfile values */
   if (loglevel < 0)
     loglevel = cfg_getint(cfg_getsec(cfg, "general"), "loglevel");
-
+  if (!logformat)
+    logformat = cfg_getstr(cfg_getsec(cfg, "general"), "logformat");
   logfile = cfg_getstr(cfg_getsec(cfg, "general"), "logfile");
 
-  ret = logger_init(logfile, logdomains, loglevel);
+  ret = logger_init(logfile, logdomains, loglevel, logformat);
   if (ret != 0)
     {
       fprintf(stderr, "Could not reinitialize log facility with config file settings\n");