SYSLOG-NG.CONF(5) The syslog-ng.conf manual page SYSLOG-NG.CONF(5)NAMEsyslog-ng.conf - syslog-ng configuration file
SYNOPSISsyslog-ng.confDESCRIPTION
This manual page is only an abstract; for the complete documentation of
syslog-ng, see The syslog-ng Open Source Edition Administrator Guide[1]
or the official syslog-ng website[2].
The syslog-ng OSE application is a flexible and highly scalable system
logging application. Typically, syslog-ng is used to manage log
messages and implement centralized logging, where the aim is to collect
the log messages of several devices on a single, central log server.
The different devices - called syslog-ng clients - all run syslog-ng,
and collect the log messages from the various applications, files, and
other sources. The clients send all important log messages to the
remote syslog-ng server, where the server sorts and stores them.
The syslog-ng application reads incoming messages and forwards them to
the selected destinations. The syslog-ng application can receive
messages from files, remote hosts, and other sources.
Log messages enter syslog-ng in one of the defined sources, and are
sent to one or more destinations.
Sources and destinations are independent objects; log paths define what
syslog-ng does with a message, connecting the sources to the
destinations. A log path consists of one or more sources and one or
more destinations; messages arriving from a source are sent to every
destination listed in the log path. A log path defined in syslog-ng is
called a log statement.
Optionally, log paths can include filters. Filters are rules that
select only certain messages, for example, selecting only messages sent
by a specific application. If a log path includes filters, syslog-ng
sends only the messages satisfying the filter rules to the destinations
set in the log path.
CONFIGURING SYSLOG-NG
· The main body of the configuration file consists of object
definitions: sources, destinations, logpaths define which log
message are received and where they are sent. All identifiers,
option names and attributes, and any other strings used in the
syslog-ng configuration file are case sensitive. Objects must be
defined before they are referenced in another statement. Object
definitions (also called statements) have the following syntax:
object_type object_id {<options>};
· Type of the object: One of source, destination, log, filter,
parser, rewrite rule, or template.
· Identifier of the object: A unique name identifying the object.
When using a reserved word as an identifier, enclose the
identifier in quotation marks.
Tip
Use identifiers that refer to the type of the object they
identify. For example, prefix source objects with s_,
destinations with d_, and so on.
· Parameters: The parameters of the object, enclosed in braces
{parameters}.
· Semicolon: Object definitions end with a semicolon (;).
For example, the following line defines a source and calls it
s_internal.
source s_internal { internal(); };
The object can be later referenced in other statements using its
ID, for example, the previous source is used as a parameter of the
following log statement:
log { source(s_internal); destination(d_file); };
· The parameters and options within a statement are similar to
function calls of the C programming language: the name of the
option followed by a list of its parameters enclosed within
brackets and terminated with a semicolon.
option(parameter1, parameter2); option2(parameter1, parameter2);
For example, the following source statement has three options; the
first two options (file() and follow_freq()) have a single
parameter, while the third one (flags()) has two parameters:
source s_tail { file("/var/log/apache/access.log"
follow_freq(1) flags(no-parse, validate-utf8)); };
Objects may have required and optional parameters. Required
parameters are positional, meaning that they must be specified in a
defined order. Optional parameters can be specified in any order
using the option(value) format. If a parameter (optional or
required) is not specified, its default value is used. The
parameters and their default values are listed in the reference
section of the particular object.
Example 1. Using required and optional parameters The unix-stream()
source driver has a single required argument: the name of the
socket to listen on. Optional parameters follow the socket name in
any order, so the following source definitions have the same
effect:
source s_demo_stream1 {
unix-stream("/dev/log" max-connections(10)group(log)); };
source s_demo_stream2 {
unix-stream("/dev/log" group(log)max-connections(10)); };
· Some options are global options, or can be set globally, for
example, whether syslog-ng OSE should use DNS resolution to resolve
IP addresses. Global options are detailed in ???.
options { use_dns(no); };
· All identifiers, attributes, and any other strings used in the
syslog-ng configuration file are case sensitive.
· Objects can be used before definition.
· To add comments to the configuration file, start a line with # and
write your comments. These lines are ignored by syslog-ng.
# Comment: This is a stream source
source s_demo_stream {
unix-stream("/dev/log" max-connections(10)group(log)); };
The syntax of log statements is as follows:
log {
source(s1); source(s2); ...
optional_element(filter1|parser1|rewrite1); optional_element(filter2|parser2|rewrite2);...
destination(d1); destination(d2); ...
flags(flag1[, flag2...]);
};
The following log statement sends all messages arriving to the
localhost to a remote server.
source s_localhost { tcp(ip(127.0.0.1) port(1999) ); };
destination d_tcp { tcp("10.1.2.3" port(1999); localport(999)); };
log { source(s_localhost); destination(d_tcp); };
The syslog-ng application has a number of global options governing DNS
usage, the timestamp format used, and other general points. Each option
may have parameters, similarly to driver specifications. To set global
options, add an option statement to the syslog-ng configuration file
using the following syntax:
options { option1(params); option2(params); ... };
The sources, destinations, and filters available in syslog-ng are
listed below. For details, see The syslog-ng Administrator Guide[1].
- .sp
Table 1. Source drivers available in syslog-ng
┌───────────────────┬────────────────────────────┐
│Name │ Description │
├───────────────────┼────────────────────────────┤
│internal() │ Messages generated │
│ │ internally in syslog-ng. │
├───────────────────┼────────────────────────────┤
│file() │ Opens the specified file │
│ │ and reads messages. │
├───────────────────┼────────────────────────────┤
│pipe(), fifo │ Opens the specified named │
│ │ pipe and reads messages. │
├───────────────────┼────────────────────────────┤
│pacct() │ Reads messages from the │
│ │ process accounting logs on │
│ │ Linux. │
├───────────────────┼────────────────────────────┤
│program() │ Opens the specified │
│ │ application and reads │
│ │ messages from its standard │
│ │ output. │
├───────────────────┼────────────────────────────┤
│sun-stream(), sun- │ Opens the specified │
│streams() │ STREAMS device on Solaris │
│ │ systems and reads incoming │
│ │ messages. │
├───────────────────┼────────────────────────────┤
│syslog() │ Listens for incoming │
│ │ messages using the new │
│ │ IETF-standard syslog │
│ │ protocol. │
├───────────────────┼────────────────────────────┤
│system() │ Automatically detects │
│ │ which platform syslog-ng │
│ │ OSE is running on, and │
│ │ collects the native log │
│ │ messages of that platform. │
├───────────────────┼────────────────────────────┤
│tcp(), tcp6() │ Listens on the specified │
│ │ TCP port for incoming │
│ │ messages using the BSD- │
│ │ syslog protocol over IPv4 │
│ │ and IPv6 networks, │
│ │ respectively. │
├───────────────────┼────────────────────────────┤
│udp(), udp6() │ Listens on the specified │
│ │ UDP port for incoming │
│ │ messages using the BSD- │
│ │ syslog protocol over IPv4 │
│ │ and IPv6 networks, │
│ │ respectively. │
├───────────────────┼────────────────────────────┤
│unix-dgram() │ Opens the specified unix │
│ │ socket in SOCK_DGRAM mode │
│ │ and listens for incoming │
│ │ messages. │
├───────────────────┼────────────────────────────┤
│unix-stream() │ Opens the specified unix │
│ │ socket in SOCK_STREAM mode │
│ │ and listens for incoming │
│ │ messages. │
└───────────────────┴────────────────────────────┘
Table 2. Destination drivers available in syslog-ng
┌─────────────────┬────────────────────────────┐
│Name │ Description │
├─────────────────┼────────────────────────────┤
│file() │ Writes messages to the │
│ │ specified file. │
├─────────────────┼────────────────────────────┤
│fifo(), pipe() │ Writes messages to the │
│ │ specified named pipe. │
├─────────────────┼────────────────────────────┤
│program() │ Forks and launches the │
│ │ specified program, and │
│ │ sends messages to its │
│ │ standard input. │
├─────────────────┼────────────────────────────┤
│sql() │ Sends messages into an SQL │
│ │ database. In addition to │
│ │ the standard syslog-ng │
│ │ packages, the sql() │
│ │ destination requires │
│ │ database-specific packages │
│ │ to be installed. Refer to │
│ │ the section appropriate │
│ │ for your platform in ???. │
├─────────────────┼────────────────────────────┤
│syslog() │ Sends messages to the │
│ │ specified remote host │
│ │ using the IETF-syslog │
│ │ protocol. The IETF │
│ │ standard supports message │
│ │ transport using the UDP, │
│ │ TCP, and TLS networking │
│ │ protocols. │
├─────────────────┼────────────────────────────┤
│tcp() and tcp6() │ Sends messages to the │
│ │ specified TCP port of a │
│ │ remote host using the BSD- │
│ │ syslog protocol over IPv4 │
│ │ and IPv6, respectively. │
├─────────────────┼────────────────────────────┤
│udp() and udp6() │ Sends messages to the │
│ │ specified UDP port of a │
│ │ remote host using the BSD- │
│ │ syslog protocol over IPv4 │
│ │ and IPv6, respectively. │
├─────────────────┼────────────────────────────┤
│unix-dgram() │ Sends messages to the │
│ │ specified unix socket in │
│ │ SOCK_DGRAM style (BSD). │
├─────────────────┼────────────────────────────┤
│unix-stream() │ Sends messages to the │
│ │ specified unix socket in │
│ │ SOCK_STREAM style (Linux). │
├─────────────────┼────────────────────────────┤
│usertty() │ Sends messages to the │
│ │ terminal of the specified │
│ │ user, if the user is │
│ │ logged in. │
└─────────────────┴────────────────────────────┘
Table 3. Filter functions available in syslog-ng OSE
┌──────────────────────┬────────────────────────────┐
│Name │ Description │
├──────────────────────┼────────────────────────────┤
│facility() │ Filter messages based on │
│ │ the sending facility. │
├──────────────────────┼────────────────────────────┤
│filter() │ Call another filter │
│ │ function. │
├──────────────────────┼────────────────────────────┤
│host() │ Filter messages based on │
│ │ the sending host. │
├──────────────────────┼────────────────────────────┤
│level() or priority() │ Filter messages based on │
│ │ their priority. │
├──────────────────────┼────────────────────────────┤
│match() │ Use a regular expression │
│ │ to filter messages based │
│ │ on a specified header or │
│ │ content field. │
├──────────────────────┼────────────────────────────┤
│message() │ Use a regular expression │
│ │ to filter messages based │
│ │ their content. │
├──────────────────────┼────────────────────────────┤
│netmask() │ Filter messages based on │
│ │ the IP address of the │
│ │ sending host. │
├──────────────────────┼────────────────────────────┤
│program() │ Filter messages based on │
│ │ the sending application. │
├──────────────────────┼────────────────────────────┤
│source() │ Select messages of the │
│ │ specified syslog-ng OSE │
│ │ source statement. │
├──────────────────────┼────────────────────────────┤
│tags() │ Select messages having the │
│ │ specified tag. │
└──────────────────────┴────────────────────────────┘
FILES
/usr/local/
/usr/local/etc/syslog-ng.conf
SEE ALSOsyslog-ng(8)
The syslog-ng OSE 3.3 Administrator Guide[1]
If you experience any problems or need help with syslog-ng, visit visit
the syslog-ng wiki[3] or the syslog-ng mailing list[4].
For news and notifications about of syslog-ng, visit the syslog-ng
Insider Blog[5].
AUTHOR
This manual page was written by the BalaBit Documentation Team
<documentation@balabit.com>.
COPYRIGHT
The authors grant permission to copy, distribute and/or modify this
manual page under the terms of the GNU General Public License Version 2
or newer (GPL v2+).
NOTES
1. The syslog-ng Open Source Edition Administrator Guide
http://www.balabit.com/support/documentation/
2. the official syslog-ng website
http://www.balabit.com/network-security/syslog-ng/
3. visit the syslog-ng wiki
http://www.balabit.com/wiki/syslog-ng-faq
4. syslog-ng mailing list
https://lists.balabit.hu/mailman/listinfo/syslog-ng
5. syslog-ng Insider Blog
http://insider.blogs.balabit.com
syslog-ng Open Source Edition 10/27/2015 SYSLOG-NG.CONF(5)
