1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title>The Rsyslogd Property Replacer</title></head>
<body>
<h1>The Property Replacer</h1>
<p><b>The property replacer is a core component in
rsyslogd's output system.</b> A syslog message has a number of
well-defined properties (see below). Each of this properties can be
accessed <b>and</b> manipulated by the property replacer.
With it, it is easy to use only part of a property value or manipulate
the value, e.g. by converting all characters to lower case.</p>
<h1>Accessing Properties</h1>
<p>Syslog message properties are used inside templates. They are
accessed by putting them between percent signs. Properties can be
modified by the property replacer. The full syntax is as follows:</p>
<blockquote><b><code>%propname:fromChar:toChar:options%</code></b></blockquote>
<h2>Available Properties</h2>
<p><b><code>propname</code></b> is the
name of the property to access. It is case-insensitive (prior to 3.17.0, they were case-senstive).
Currently supported are:</p>
<table>
<tbody>
<tr>
<td><b>msg</b></td>
<td>the MSG part of the message (aka "the message" ;))</td>
</tr>
<tr>
<td><b>rawmsg</b></td>
<td>the message excactly as it was received from the
socket. Should be useful for debugging.</td>
</tr>
<tr>
<td><b>uxtradmsg</b></td>
<td>will disappear soon - do NOT use!</td>
</tr>
<tr>
<td><b>hostname</b></td>
<td>hostname from the message</td>
</tr>
<tr>
<td><b>source</b></td>
<td>alias for HOSTNAME</td>
</tr>
<tr>
<td><b>fromhost</b></td>
<td>hostname of the system the message was received from
(in a relay chain, this is the system immediately in front of us and
not necessarily the original sender). This is a DNS-resolved name, except
if that is not possible or DNS resolution has been disabled.</td>
</tr>
<tr>
<td><b>fromhost-ip</b></td>
<td>The same as fromhost, but alsways as an IP address. Local inputs
(like imklog) use 127.0.0.1 in this property.</td>
</tr>
<tr>
<td><b>syslogtag</b></td>
<td>TAG from the message</td>
</tr>
<tr>
<td><b>programname</b></td>
<td>the "static" part of the tag, as defined by
BSD syslogd. For example, when TAG is "named[12345]", programname is
"named".</td>
</tr>
<tr>
<td><b>pri</b></td>
<td>PRI part of the message - undecoded (single value)</td>
</tr>
<tr>
<td><b>pri-text</b></td>
<td>the PRI part of the message in a textual form (e.g.
"syslog.info")</td>
</tr>
<tr>
<td><span style="font-weight: bold;">iut</span></td>
<td>the monitorware InfoUnitType - used when talking
to a <a href="http://www.monitorware.com">MonitorWare</a>
backend (also for <a href="http://www.phplogcon.org/">phpLogCon</a>)</td>
</tr>
<tr>
<td><b>syslogfacility</b></td>
<td>the facility from the message - in numerical form</td>
</tr>
<tr>
<td><b>syslogfacility-text</b></td>
<td>the facility from the message - in text form</td>
</tr>
<tr>
<td><b>syslogseverity</b></td>
<td>severity from the message - in numerical form</td>
</tr>
<tr>
<td><b>syslogseverity-text</b></td>
<td>severity from the message - in text form</td>
</tr>
<tr>
<td><b>syslogpriority</b></td>
<td>an alias for syslogseverity - included for historical
reasons (be careful: it still is the severity, not PRI!)</td>
</tr>
<tr>
<td><b>syslogpriority-text</b></td>
<td>an alias for syslogseverity-text</td>
</tr>
<tr>
<td><b>timegenerated</b></td>
<td>timestamp when the message was RECEIVED. Always in high
resolution</td>
</tr>
<tr>
<td><b>timereported</b></td>
<td>timestamp from the message. Resolution depends on
what was provided in the message (in most cases,
only seconds)</td>
</tr>
<tr>
<td><b>timestamp</b></td>
<td>alias for timereported</td>
</tr>
<tr>
<td><b>protocol-version</b></td>
<td>The contents of the PROTCOL-VERSION field from IETF
draft draft-ietf-syslog-protcol</td>
</tr>
<tr>
<td><b>structured-data</b></td>
<td>The contents of the STRUCTURED-DATA field from IETF
draft draft-ietf-syslog-protocol</td>
</tr>
<tr>
<td><b>app-name</b></td>
<td>The contents of the APP-NAME field from IETF draft
draft-ietf-syslog-protocol</td>
</tr>
<tr>
<td><b>procid</b></td>
<td>The contents of the PROCID field from IETF draft
draft-ietf-syslog-protocol</td>
</tr>
<tr>
<td height="24"><b>msgid</b></td>
<td height="24">The contents of the MSGID field from
IETF draft draft-ietf-syslog-protocol</td>
</tr>
<tr>
<td><b>$now</b></td>
<td>The current date stamp in the format YYYY-MM-DD</td>
</tr>
<tr>
<td><b>$year</b></td>
<td>The current year (4-digit)</td>
</tr>
<tr>
<td><b>$month</b></td>
<td>The current month (2-digit)</td>
</tr>
<tr>
<td><b>$day</b></td>
<td>The current day of the month (2-digit)</td>
</tr>
<tr>
<td><b>$hour</b></td>
<td>The current hour in military (24 hour) time (2-digit)</td>
</tr>
<tr>
<td><b>$hhour</b></td>
<td>The current half hour we are in. From minute 0 to 29,
this is always 0 while
from 30 to 59 it is always 1.</td>
</tr>
<tr>
<td><b>$qhour</b></td>
<td>The current quarter hour we are in. Much like $HHOUR, but values
range from 0 to 3 (for the four quater hours that are in each hour)</td>
</tr>
<tr>
<td><b>$minute</b></td>
<td>The current minute (2-digit)</td>
</tr>
</tbody>
</table>
<p>Properties starting with a $-sign are so-called system
properties. These do NOT stem from the message but are rather
internally-generated.</p>
<h2>Character Positions</h2>
<p><b><code>FromChar</code></b> and <b><code>toChar</code></b>
are used to build substrings. They specify the offset within the string
that should be copied. Offset counting starts at 1, so if you need to
obtain the first 2 characters of the message text, you can use this
syntax: "%msg:1:2%". If you do not whish to specify from and to, but
you want to specify options, you still need to include the colons. For
example, if you would like to convert the full message text to lower
case, use "%msg:::lowercase%". If you would like to extract from a
position until the end of the string, you can place a dollar-sign ("$")
in toChar (e.g. %msg:10:$%, which will extract from position 10 to the
end of the string).</p>
<p>There is also support for <b>regular expressions</b>.
To use them, you need to place a "R" into FromChar. This tells rsyslog
that a regular expression instead of position-based extraction is
desired. The actual regular expression must then be provided in toChar.
The regular expression <b>must</b> be followed by the
string "--end". It denotes the end of the regular expression and will
not become part of it. If you are using regular expressions, the
property replacer will return the part of the property text that
matches the regular expression. An example for a property replacer
sequence with a regular expression is: "%msg:R:.*Sev:. \(.*\)
\[.*--end%"</p>
<p>It is possible to specify some parametes after the "R". These are
comma-separated. They are:
<p>R,<regexp-type>,<submatch>,<nomatch>
<p>regexp-type is either "BRE" for Posix basic regular expressions or
"ERE" for extended ones. The string must be given in upper case. The
default is "BRE" to be consistent with earlier versions of rsyslog that
did not support ERE. The submatch identifies the submatch to be used
with the result. A single digit is supported. Match 0 is the full match,
while 1 to 9 are the acutal submatches.
<p>nomatch is either "DFLT", "BLANK" or "FIELD" (all upper case!). It tells
what to use if no match is found. With "DFLT", the strig "**NO MATCH**" is
used. This was the only supported value up to rsyslog 3.19.5. With "BLANK"
a blank text is used (""). Finally, "FIELD" uses the full property text
instead of the expression. Some folks have requested that, so it seems
to be useful.
<p>The following is a sample of an ERE expression that takes the first
submatch from the message string and replaces the expression with
the full field if no match is found:
<p>%msg:R,ERE,1,FIELD:for (vlan[0-9]*):--end%
<p><b>Also, extraction can be done based on so-called
"fields"</b>. To do so, place a "F" into FromChar. A field in its
current definition is anything that is delimited by a delimiter
character. The delimiter by default is TAB (US-ASCII value 9). However,
if can be changed to any other US-ASCII character by specifying a comma
and the <b>decimal</b> US-ASCII value of the delimiter
immediately after the "F". For example, to use comma (",") as a
delimiter, use this field specifier: "F,44". If your syslog
data is delimited, this is a quicker way to extract than via regular
expressions (actually, a *much* quicker way). Field counting starts at
1. Field zero is accepted, but will always lead to a "field not found"
error. The same happens if a field number higher than the number of
fields in the property is requested. The field number must be placed in
the "ToChar" parameter. An example where the 3rd field (delimited by
TAB) from the msg property is extracted is as follows: "%msg:F:3%". The
same example with semicolon as delimiter is "%msg:F,59:3%".</p>
<p>Please note that the special characters "F" and "R" are
case-sensitive. Only upper case works, lower case will return an error.
There are no white spaces permitted inside the sequence (that will lead
to error messages and will NOT provide the intended result).<br>
</p>
<h2>Property Options</h2>
<b><code>property options</code></b> are
case-insensitive. Currently, the following options are defined:
<p></p>
<table>
<tbody>
<tr>
<td><b>uppercase</b></td>
<td>convert property to lowercase only</td>
</tr>
<tr>
<td><b>lowercase</b></td>
<td>convert property text to uppercase only</td>
</tr>
<tr>
<td><b>drop-last-lf</b></td>
<td>The last LF in the message (if any), is dropped.
Especially useful for PIX.</td>
</tr>
<tr>
<td><b>date-mysql</b></td>
<td>format as mysql date</td>
</tr>
<tr>
<td><b>date-rfc3164</b></td>
<td>format as RFC 3164 date</td>
</tr>
<tr>
<td><b>date-rfc3339</b></td>
<td>format as RFC 3339 date</td>
</tr>
<tr>
<td><b>escape-cc</b></td>
<td>replace control characters (ASCII value 127 and values
less then 32) with an escape sequence. The sequnce is
"#<charval>" where charval is the 3-digit decimal value
of the control character. For example, a tabulator would be replaced by
"#009".<br>
Note: using this option requires that <a href="rsconf1_escapecontrolcharactersonreceive.html">$EscapeControlCharactersOnReceive</a>
is set to off.</td>
</tr>
<tr>
<td><b>space-cc</b></td>
<td>replace control characters by spaces<br>
Note: using this option requires that <a href="rsconf1_escapecontrolcharactersonreceive.html">$EscapeControlCharactersOnReceive</a>
is set to off.</td>
</tr>
<tr>
<td><b>drop-cc</b></td>
<td>drop control characters - the resulting string will
neither contain control characters, escape sequences nor any other
replacement character like space.<br>
Note: using this option requires that <a href="rsconf1_escapecontrolcharactersonreceive.html">$EscapeControlCharactersOnReceive</a>
is set to off.</td>
</tr>
</tbody>
</table>
<h2>Further Links</h2>
<ul>
<li>Article on "<a href="rsyslog_recording_pri.html">Recording
the Priority of Syslog Messages</a>" (describes use of templates
to record severity and facility of a message)</li>
<li><a href="rsyslog_conf.html">Configuration file
syntax</a>, this is where you actually use the property replacer.</li>
</ul>
</body></html>
|
