MEDIUM: log: support a new "short" format
This format is meant to be used with local file descriptors. It emits
messages only prefixed with a level, removing all the process name,
system name, date and so on. It is similar to the printk() format used
on Linux. It's suitable to be sent to a local logger compatible with
systemd's output format.
Note that the facility is still required but not used, hence it is
suggested to use "daemon" to remind that it's a local logger.
Example :
log stdout format short daemon # send everything to stdout
log stderr format short daemon notice # send important events to stderr
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 9f4fb59..89fddc1 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -856,7 +856,7 @@
as non-blocking calls will be ignored. Also there will be no way to
purge nor rotate this file without restarting the process. Note that
the configured syslog format is preserved, so the output is suitable
- for use with a TCP syslog server.
+ for use with a TCP syslog server. See also the "short" format below.
- "stdout" / "stderr", which are respectively aliases for "fd@1" and
"fd@2", see above.
@@ -886,11 +886,22 @@
rfc5424 The RFC5424 syslog message format.
(https://tools.ietf.org/html/rfc5424)
+ short A message containing only a level between angle brackets such as
+ '<3>', followed by the text. The PID, date, time, process name
+ and system name are omitted. This is designed to be used with a
+ local log server. This format is compatible with what the systemd
+ logger consumes.
+
<facility> must be one of the 24 standard syslog facilities :
+ kern user mail daemon auth syslog lpr news
+ uucp cron auth2 ftp ntp audit alert cron2
+ local0 local1 local2 local3 local4 local5 local6 local7
+
- kern user mail daemon auth syslog lpr news
- uucp cron auth2 ftp ntp audit alert cron2
- local0 local1 local2 local3 local4 local5 local6 local7
+ Note that the facility is ignored for the "short" format, but
+ still required as a positional field. It is recommended to use
+ "daemon" in this case to make it clear that it's only supposed to
+ be used locally.
An optional level can be specified to filter outgoing messages. By default,
all messages are sent. If a maximum level is specified, only messages with a
@@ -5136,7 +5147,7 @@
ignored. Also there will be no way to purge nor rotate this
file without restarting the process. Note that the configured
syslog format is preserved, so the output is suitable for use
- with a TCP syslog server.
+ with a TCP syslog server. See also the "short" format below.
- "stdout" / "stderr", which are respectively aliases for "fd@1"
and "fd@2", see above.
@@ -5165,11 +5176,22 @@
rfc5424 The RFC5424 syslog message format.
(https://tools.ietf.org/html/rfc5424)
+ short A message containing only a level between angle brackets such as
+ '<3>', followed by the text. The PID, date, time, process name
+ and system name are omitted. This is designed to be used with a
+ local log server. This format is compatible with what the
+ systemd logger consumes.
+
<facility> must be one of the 24 standard syslog facilities :
- kern user mail daemon auth syslog lpr news
- uucp cron auth2 ftp ntp audit alert cron2
- local0 local1 local2 local3 local4 local5 local6 local7
+ kern user mail daemon auth syslog lpr news
+ uucp cron auth2 ftp ntp audit alert cron2
+ local0 local1 local2 local3 local4 local5 local6 local7
+
+ Note that the facility is ignored for the "short" format, but
+ still required as a positional field. It is recommended to use
+ "daemon" in this case to make it clear that it's only supposed
+ to be used locally.
<level> is optional and can be specified to filter outgoing messages. By
default, all messages are sent. If a level is specified, only
@@ -5196,6 +5218,8 @@
Example :
log global
+ log stdout format short daemon # send everything to stdout
+ log stderr format short daemon notice # send important events to stderr
log 127.0.0.1:514 local0 notice # only send important events
log 127.0.0.1:514 local0 notice notice # same but limit output level
log "${LOCAL_SYSLOG}:514" local0 notice # send to local server
diff --git a/include/types/log.h b/include/types/log.h
index c394d77..3813cfb 100644
--- a/include/types/log.h
+++ b/include/types/log.h
@@ -41,6 +41,7 @@
enum {
LOG_FORMAT_RFC3164 = 0,
LOG_FORMAT_RFC5424,
+ LOG_FORMAT_SHORT,
LOG_FORMATS, /* number of supported log formats, must always be last */
};
diff --git a/src/log.c b/src/log.c
index c8ee6a9..2aef552 100644
--- a/src/log.c
+++ b/src/log.c
@@ -67,7 +67,14 @@
.sep1 = { .area = " ", .data = 1 },
.sep2 = { .area = " - ", .data = 3 }
}
- }
+ },
+ [LOG_FORMAT_SHORT] = {
+ .name = "short",
+ .pid = {
+ .sep1 = { .area = "", .data = 0 },
+ .sep2 = { .area = " ", .data = 1 },
+ }
+ },
};
#define FD_SETS_ARE_BITFIELDS
@@ -1329,7 +1336,8 @@
const struct logsrv *logsrv = tmp;
int *plogfd = logsrv->addr.ss_family == AF_UNIX ?
&logfdunix : &logfdinet;
- char *pid_sep1 = NULL, *pid_sep2 = NULL;
+ char *pid_sep1 = "", *pid_sep2 = "";
+ char logheader_short[3];
int sent;
int maxlen;
int hdr_max = 0;
@@ -1383,6 +1391,18 @@
sd_max = sd_size; /* the SD part allowed only in RFC5424 */
break;
+ case LOG_FORMAT_SHORT:
+ /* all fields are known, skip the header generation */
+ hdr = logheader_short;
+ hdr[0] = '<';
+ hdr[1] = '0' + MAX(level, logsrv->minlvl);
+ hdr[2] = '>';
+ hdr_ptr = hdr;
+ hdr_max = 3;
+ maxlen = logsrv->maxlen - hdr_max;
+ max = MIN(size, maxlen) - 1;
+ goto send;
+
default:
continue; /* must never happen */
}