docs/manual/mod/mod_journald.xml

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<modulesynopsis metafile="mod_journald.xml.meta">

<name>mod_journald</name>
<description>Provides "journald" ErrorLog provider</description>
<status>Extension</status>
<sourcefile>mod_journald.c</sourcefile>
<identifier>journald_module</identifier>

<summary>
    <p>This module provides "journald" ErrorLog provider. It allows logging
    error messages and CustomLog/TransferLog via systemd-journald(8).</p>
</summary>

<section id="structured">
    <title>Structured logging</title>
    <p>Systemd-journald allows structured logging and therefore it is
    possible to filter logged messages according to various variables.
    Currently supported variables are:
    </p>
    <dl>
      <dt><code>LOG</code></dt>
      <dd>The name of the log. For ErrorLog, the value is "error_log".
          For CustomLog or TransferLog, the value is the first argument of
          these directives.</dd>
      <dt><code>REQUEST_HOSTNAME</code></dt>
      <dd>Host, as set by full URI or Host: header in the request.</dd>
      <dt><code>REQUEST_USER</code></dt>
      <dd>If an authentication check was made, this gets set to the user
          name.</dd>
      <dt><code>REQUEST_USERAGENT_IP</code></dt>
      <dd>The address that originated the request.</dd>
      <dt><code>REQUEST_URI</code></dt>
      <dd>The path portion of the URI, or "/" if no path provided.</dd>
      <dt><code>SERVER_HOSTNAME</code></dt>
      <dd>The hostname of server for which the log message has been
          generated.</dd>
    </dl>

    <p>These variables can be for example used to show only log messages
    for particular URI using <code>journalctl</code>:
    </p>

    <highlight>journalctl REQUEST_URI=/index.html -a</highlight>

    <p>For more examples, see systemd-journalctl documentation.</p>
</section>

<section id="examples">
    <title>Examples</title>

    <p>Using <code>journald</code> in ErrorLog directive (see <module>core</module>)
    instead of a filename enables logging via systemd-journald(8)
    if the system supports it.
    </p>

    <highlight language="config">
ErrorLog journald
    </highlight>

    <p>Using <code>journald</code> as an error log provider in CustomLog
    directive (see <module>mod_log_config</module>) enables
    logging via systemd-journald(8) if the system supports it.
    </p>

    <highlight language="config">
CustomLog "journald" "%h %l %u %t \"%r\" %>s %b"
    </highlight>

    <note type="warning"><title>Performance warning</title><p>
    Currently, systemd-journald is not designed for high-throughput logging
    and logging access_log to systemd-journald could decrease the performance
    a lot.
    </p></note>

</section>

</modulesynopsis>