man: add description of org.freedesktop.LogControl1

I'm not sure if the LogTarget property is sufficiently general to be made into
a property that can be generally implemented. It is very closely tied to the internal
systemd logic. The other two seem fine thoough.

1 files changed, 106 insertions, 0 deletions

diff --git a/man/org.freedesktop.LogControl1.xml b/man/org.freedesktop.LogControl1.xml
new file mode 100644
index 0000000000..125a008347
--- /dev/null
+++ b/man/org.freedesktop.LogControl1.xml
@@ -0,0 +1,106 @@
+<?xml version='1.0'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" >
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
+
+<refentry id="org.freedesktop.LogControl1"
+    xmlns:xi="http://www.w3.org/2001/XInclude">
+  <refentryinfo>
+    <title>org.freedesktop.LogControl1</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>org.freedesktop.LogControl1</refentrytitle>
+    <manvolnum>5</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>org.freedesktop.LogControl1</refname>
+    <refpurpose>D-Bus interface to query and set logging configuration</refpurpose>
+  </refnamediv>
+
+  <refsect1>
+    <title>Introduction</title>
+
+    <para><interfacename>org.freedesktop.LogControl1</interfacename> is a generic interface that is intended
+    to be used by any daemon which should allow setting the log level and target over D-Bus. It is implemented
+    by various daemons that are part of the
+    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> suite.</para>
+
+    <para>It is assumed that those settings are global for the whole program, so a fixed object path is
+    used. The interface should always be available under the path
+    <filename>/org/freedesktop/LogControl1</filename>.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para>The following interface is exposed:</para>
+
+    <programlisting executable="systemd" node="/org/freedesktop/LogControl1" interface="org.freedesktop.LogControl1">
+node /org/freedesktop/LogControl1 {
+  interface org.freedesktop.LogControl1 {
+    properties:
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      @org.freedesktop.systemd1.Privileged("true")
+      readwrite s LogLevel = '...';
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      @org.freedesktop.systemd1.Privileged("true")
+      readwrite s LogTarget = '...';
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly s SyslogIdentifier = '...';
+  };
+  interface org.freedesktop.DBus.Peer { ... };
+  interface org.freedesktop.DBus.Introspectable { ... };
+  interface org.freedesktop.DBus.Properties { ... };
+};
+    </programlisting>
+
+    <!--Autogenerated cross-references for systemd.directives, do not edit-->
+
+    <variablelist class="dbus-interface" generated="True" extra-ref="org.freedesktop.LogControl1"/>
+
+    <variablelist class="dbus-interface" generated="True" extra-ref="org.freedesktop.LogControl1"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="LogLevel"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="LogTarget"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="SyslogIdentifier"/>
+
+    <!--End of Autogenerated section-->
+
+    <refsect2>
+      <title>Properties</title>
+
+      <para><varname>LogLevel</varname> describes the
+      <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>-style
+      log-level, and should be one of <literal>emerg</literal>, <literal>alert</literal>,
+      <literal>crit</literal>, <literal>err</literal>, <literal>warning</literal>, <literal>notice</literal>,
+      <literal>info</literal>, <literal>debug</literal>, in order of increasing verbosity.</para>
+
+      <para><varname>LogTarget</varname> describes the log target (mechanism). It should be one of
+      <literal>console</literal> (log to the console or standard output),
+      <literal>kmsg</literal> (log to the kernel ring buffer),
+      <literal>journal</literal> (log the the journal natively, see
+      <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>),
+      <literal>syslog</literal> (log using the
+      <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> call).
+      </para>
+
+      <para>Those two properties are writable, so they may be set by sufficiently privileged users.</para>
+
+      <para><varname>SyslogIdentifier</varname> is a read-only property that shows the "syslog identifier".
+      It is a short string that identifies the program that is the source of log messages that is passed to
+      the <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> call.
+      </para>
+
+      <para>Note: <command>journalctl</command> option <option>-p</option>/<option>--priority=</option> may
+      be used to filter log messages by log level, option <option>-t</option>/<option>--identifier=</option>
+      may be used to by the syslog identifier, and filters like <literal>_TRANSPORT=syslog</literal>,
+      <literal>_TRANSPORT=journal</literal>, and <literal>_TRANSPORT=kernel</literal> may be used to filter
+      messages by the mechanism through which they reached <command>systemd-journald</command>.</para>
+    </refsect2>
+  </refsect1>
+</refentry>