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
This commit is contained in:
Willy Tarreau 2018-11-12 08:45:00 +01:00
parent 5a32ecc6cf
commit e8746a08b2
3 changed files with 55 additions and 10 deletions

View File

@ -856,7 +856,7 @@ log <address> [len <length>] [format <format>] <facility> [max level [min level]
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 @@ log <address> [len <length>] [format <format>] <facility> [max level [min level]
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 @@ no log
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 @@ no log
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 @@ no log
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

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@ -41,6 +41,7 @@ extern const char *log_levels[];
enum {
LOG_FORMAT_RFC3164 = 0,
LOG_FORMAT_RFC5424,
LOG_FORMAT_SHORT,
LOG_FORMATS, /* number of supported log formats, must always be last */
};

View File

@ -67,7 +67,14 @@ static const struct log_fmt log_formats[LOG_FORMATS] = {
.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 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
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 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
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 */
}