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<article name="Logging to syslog"
         link="/en/docs/syslog.html"
         lang="en"
         rev="6">

<section>

<para>
The
<link doc="ngx_core_module.xml" id="error_log"/>
and
<link doc="http/ngx_http_log_module.xml" id="access_log"/>
directives support logging to syslog.
The following parameters configure logging to syslog:
<list type="tag">

<tag-name><literal>server=</literal><value>address</value></tag-name>
<tag-desc>
Defines the address of a syslog server.
The address can be specified as a domain name or IP address,
with an optional port, or as a UNIX-domain socket path
specified after the “<literal>unix:</literal>” prefix.
If port is not specified, the UDP port 514 is used.
If a domain name resolves to several IP addresses, the first resolved
address is used.
</tag-desc>

<tag-name><literal>facility=</literal><value>string</value></tag-name>
<tag-desc>
Sets facility of syslog messages, as defined in
<link url="https://datatracker.ietf.org/doc/html/rfc3164#section-4.1.1">RFC 3164</link>.
Facility can be one of “<literal>kern</literal>”, “<literal>user</literal>”,
“<literal>mail</literal>”, “<literal>daemon</literal>”,
“<literal>auth</literal>”, “<literal>intern</literal>”,
“<literal>lpr</literal>”, “<literal>news</literal>”, “<literal>uucp</literal>”,
“<literal>clock</literal>”, “<literal>authpriv</literal>”,
“<literal>ftp</literal>”, “<literal>ntp</literal>”, “<literal>audit</literal>”,
“<literal>alert</literal>”, “<literal>cron</literal>”,
“<literal>local0</literal>”..“<literal>local7</literal>”.
Default is “<literal>local7</literal>”.
</tag-desc>

<tag-name><literal>severity=</literal><value>string</value></tag-name>
<tag-desc>
Sets severity of syslog messages for
<link doc="http/ngx_http_log_module.xml" id="access_log"/>,
as defined in
<link url="https://datatracker.ietf.org/doc/html/rfc3164#section-4.1.1">RFC 3164</link>.
Possible values are the same as for the second parameter (level) of the
<link doc="ngx_core_module.xml" id="error_log"/> directive.
Default is “<literal>info</literal>”.
<note>
Severity of error messages is determined by nginx, thus the parameter
is ignored in the <literal>error_log</literal> directive.
</note>
</tag-desc>

<tag-name><literal>tag=</literal><value>string</value></tag-name>
<tag-desc>
Sets the tag of syslog messages.
Default is “<literal>nginx</literal>”.
</tag-desc>

<tag-name><literal>nohostname</literal></tag-name>
<tag-desc>
Disables adding the “hostname” field into the syslog message header (1.9.7).
</tag-desc>

<!--
<tag-name><literal>bare=</literal><literal>on</literal> |
<literal>off</literal></tag-name>
<tag-desc>
If enabled, messages are sent without syslog headers.
Default is <literal>off</literal>.
</tag-desc>
-->

</list>
Example syslog configuration:
<example>
error_log syslog:server=192.168.1.1 debug;

access_log syslog:server=unix:/var/log/nginx.sock,nohostname;
access_log syslog:server=[2001:db8::1]:12345,facility=local7,tag=nginx,severity=info combined;
</example>
</para>

<para>
<note>
Logging to syslog is available since version 1.7.1.
As part of our
<commercial_version>commercial subscription</commercial_version>
logging to syslog is available since version 1.5.3.
</note>
</para>

</section>

</article>