]>
Commit | Line | Data |
---|---|---|
c5abba08 LP |
1 | <?xml version='1.0'?> <!--*-nxml-*--> |
2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
c5abba08 LP |
4 | |
5 | <!-- | |
6 | This file is part of systemd. | |
7 | ||
8 | Copyright 2010 Lennart Poettering | |
9 | ||
10 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
11 | under the terms of the GNU Lesser General Public License as published by |
12 | the Free Software Foundation; either version 2.1 of the License, or | |
c5abba08 LP |
13 | (at your option) any later version. |
14 | ||
15 | systemd is distributed in the hope that it will be useful, but | |
16 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 18 | Lesser General Public License for more details. |
c5abba08 | 19 | |
5430f7f2 | 20 | You should have received a copy of the GNU Lesser General Public License |
c5abba08 LP |
21 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
22 | --> | |
23 | ||
dfdebb1b | 24 | <refentry id="systemd-notify" |
798d3a52 ZJS |
25 | xmlns:xi="http://www.w3.org/2001/XInclude"> |
26 | ||
27 | <refentryinfo> | |
28 | <title>systemd-notify</title> | |
29 | <productname>systemd</productname> | |
30 | ||
31 | <authorgroup> | |
32 | <author> | |
33 | <contrib>Developer</contrib> | |
34 | <firstname>Lennart</firstname> | |
35 | <surname>Poettering</surname> | |
36 | <email>lennart@poettering.net</email> | |
37 | </author> | |
38 | </authorgroup> | |
39 | </refentryinfo> | |
40 | ||
41 | <refmeta> | |
42 | <refentrytitle>systemd-notify</refentrytitle> | |
43 | <manvolnum>1</manvolnum> | |
44 | </refmeta> | |
45 | ||
46 | <refnamediv> | |
47 | <refname>systemd-notify</refname> | |
48 | <refpurpose>Notify service manager about start-up completion and other daemon status changes</refpurpose> | |
49 | </refnamediv> | |
50 | ||
51 | <refsynopsisdiv> | |
52 | <cmdsynopsis> | |
53 | <command>systemd-notify <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt" rep="repeat">VARIABLE=VALUE</arg></command> | |
54 | </cmdsynopsis> | |
55 | </refsynopsisdiv> | |
56 | ||
57 | <refsect1> | |
58 | <title>Description</title> | |
59 | ||
60 | <para><command>systemd-notify</command> may be called by daemon | |
61 | scripts to notify the init system about status changes. It can be | |
62 | used to send arbitrary information, encoded in an | |
b938cb90 | 63 | environment-block-like list of strings. Most importantly, it can be |
798d3a52 ZJS |
64 | used for start-up completion notification.</para> |
65 | ||
66 | <para>This is mostly just a wrapper around | |
67 | <function>sd_notify()</function> and makes this functionality | |
68 | available to shell scripts. For details see | |
69 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>. | |
70 | </para> | |
71 | ||
72 | <para>The command line may carry a list of environment variables | |
73 | to send as part of the status update.</para> | |
74 | ||
b3bb6476 LP |
75 | <para>Note that systemd will refuse reception of status updates from this command unless |
76 | <varname>NotifyAccess=</varname> is set for the service unit this command is called from.</para> | |
77 | ||
78 | <para>Note that <function>sd_notify()</function> notifications may be attributed to units correctly only if either | |
79 | the sending process is still around at the time PID 1 processes the message, or if the sending process is | |
80 | explicitly runtime-tracked by the service manager. The latter is the case if the service manager originally forked | |
81 | off the process, i.e. on all processes that match <varname>NotifyAccess=</varname><option>main</option> or | |
82 | <varname>NotifyAccess=</varname><option>exec</option>. Conversely, if an auxiliary process of the unit sends an | |
83 | <function>sd_notify()</function> message and immediately exits, the service manager might not be able to properly | |
84 | attribute the message to the unit, and thus will ignore it, even if | |
85 | <varname>NotifyAccess=</varname><option>all</option> is set for it.</para> | |
aa203945 LP |
86 | |
87 | <para><command>systemd-notify</command> will first attempt to invoke <function>sd_notify()</function> pretending to | |
88 | have the PID of the invoking process. This will only succeed when invoked with sufficient privileges. On failure, | |
89 | it will then fall back to invoking it under its own PID. This behaviour is useful in order that when the tool is | |
90 | invoked from a shell script the shell process — and not the <command>systemd-notify</command> process — appears as | |
91 | sender of the message, which in turn is helpful if the shell process is the main process of a service, due to the | |
92 | limitations of <varname>NotifyAccess=</varname><option>all</option> described above.</para> | |
798d3a52 ZJS |
93 | </refsect1> |
94 | ||
95 | <refsect1> | |
96 | <title>Options</title> | |
97 | ||
98 | <para>The following options are understood:</para> | |
99 | ||
100 | <variablelist> | |
101 | <varlistentry> | |
102 | <term><option>--ready</option></term> | |
103 | ||
104 | <listitem><para>Inform the init system about service start-up | |
105 | completion. This is equivalent to <command>systemd-notify | |
106 | READY=1</command>. For details about the semantics of this | |
107 | option see | |
108 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> | |
109 | </varlistentry> | |
110 | ||
111 | <varlistentry> | |
112 | <term><option>--pid=</option></term> | |
113 | ||
114 | <listitem><para>Inform the init system about the main PID of | |
115 | the daemon. Takes a PID as argument. If the argument is | |
116 | omitted, the PID of the process that invoked | |
117 | <command>systemd-notify</command> is used. This is equivalent | |
118 | to <command>systemd-notify MAINPID=$PID</command>. For details | |
119 | about the semantics of this option see | |
120 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> | |
121 | </varlistentry> | |
122 | ||
123 | <varlistentry> | |
124 | <term><option>--status=</option></term> | |
125 | ||
126 | <listitem><para>Send a free-form status string for the daemon | |
127 | to the init systemd. This option takes the status string as | |
128 | argument. This is equivalent to <command>systemd-notify | |
1eecafb8 | 129 | STATUS=…</command>. For details about the semantics of this |
798d3a52 ZJS |
130 | option see |
131 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> | |
132 | </varlistentry> | |
133 | ||
134 | <varlistentry> | |
135 | <term><option>--booted</option></term> | |
136 | ||
137 | <listitem><para>Returns 0 if the system was booted up with | |
138 | systemd, non-zero otherwise. If this option is passed, no | |
139 | message is sent. This option is hence unrelated to the other | |
140 | options. For details about the semantics of this option, see | |
94f099d8 | 141 | <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>. An |
a8eaaee7 | 142 | alternate way to check for this state is to call |
94f099d8 LP |
143 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> |
144 | with the <command>is-system-running</command> command. It will | |
145 | return <literal>offline</literal> if the system was not booted | |
146 | with systemd. </para></listitem> | |
798d3a52 ZJS |
147 | </varlistentry> |
148 | ||
149 | <xi:include href="standard-options.xml" xpointer="help" /> | |
150 | <xi:include href="standard-options.xml" xpointer="version" /> | |
151 | </variablelist> | |
152 | ||
153 | </refsect1> | |
154 | ||
155 | <refsect1> | |
156 | <title>Exit status</title> | |
157 | ||
158 | <para>On success, 0 is returned, a non-zero failure code | |
159 | otherwise.</para> | |
160 | </refsect1> | |
161 | ||
162 | <refsect1> | |
163 | <title>Example</title> | |
164 | ||
165 | <example> | |
166 | <title>Start-up Notification and Status Updates</title> | |
167 | ||
168 | <para>A simple shell daemon that sends start-up notifications | |
169 | after having set up its communication channel. During runtime it | |
170 | sends further status updates to the init system:</para> | |
171 | ||
172 | <programlisting>#!/bin/bash | |
c61fbdfc LP |
173 | |
174 | mkfifo /tmp/waldo | |
1eecafb8 | 175 | systemd-notify --ready --status="Waiting for data…" |
c61fbdfc LP |
176 | |
177 | while : ; do | |
0521e286 LP |
178 | read a < /tmp/waldo |
179 | systemd-notify --status="Processing $a" | |
c61fbdfc | 180 | |
1eecafb8 | 181 | # Do something with $a … |
c61fbdfc | 182 | |
1eecafb8 | 183 | systemd-notify --status="Waiting for data…" |
c61fbdfc | 184 | done</programlisting> |
798d3a52 ZJS |
185 | </example> |
186 | </refsect1> | |
187 | ||
188 | <refsect1> | |
189 | <title>See Also</title> | |
190 | <para> | |
191 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
192 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
193 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
194 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
195 | <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
196 | </para> | |
197 | </refsect1> | |
c5abba08 LP |
198 | |
199 | </refentry> |