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diff --git a/man/sd_notify.xml b/man/sd_notify.xml deleted file mode 100644 index 94542b80b8..0000000000 --- a/man/sd_notify.xml +++ /dev/null @@ -1,405 +0,0 @@ -<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> -<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" - "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> - -<!-- - This file is part of systemd. - - Copyright 2010 Lennart Poettering - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. ---> - -<refentry id="sd_notify" - xmlns:xi="http://www.w3.org/2001/XInclude"> - - <refentryinfo> - <title>sd_notify</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Lennart</firstname> - <surname>Poettering</surname> - <email>lennart@poettering.net</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>sd_notify</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd_notify</refname> - <refname>sd_notifyf</refname> - <refname>sd_pid_notify</refname> - <refname>sd_pid_notifyf</refname> - <refname>sd_pid_notify_with_fds</refname> - <refpurpose>Notify service manager about start-up completion and other service status changes</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-daemon.h></funcsynopsisinfo> - - <funcprototype> - <funcdef>int <function>sd_notify</function></funcdef> - <paramdef>int <parameter>unset_environment</parameter></paramdef> - <paramdef>const char *<parameter>state</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_notifyf</function></funcdef> - <paramdef>int <parameter>unset_environment</parameter></paramdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>...</paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_pid_notify</function></funcdef> - <paramdef>pid_t <parameter>pid</parameter></paramdef> - <paramdef>int <parameter>unset_environment</parameter></paramdef> - <paramdef>const char *<parameter>state</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_pid_notifyf</function></funcdef> - <paramdef>pid_t <parameter>pid</parameter></paramdef> - <paramdef>int <parameter>unset_environment</parameter></paramdef> - <paramdef>const char *<parameter>format</parameter></paramdef> - <paramdef>...</paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_pid_notify_with_fds</function></funcdef> - <paramdef>pid_t <parameter>pid</parameter></paramdef> - <paramdef>int <parameter>unset_environment</parameter></paramdef> - <paramdef>const char *<parameter>state</parameter></paramdef> - <paramdef>const int *<parameter>fds</parameter></paramdef> - <paramdef>unsigned <parameter>n_fds</parameter></paramdef> - </funcprototype> - </funcsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - <para><function>sd_notify()</function> may be called by a service - to notify the service manager about state changes. It can be used - to send arbitrary information, encoded in an - environment-block-like string. Most importantly, it can be used for - start-up completion notification.</para> - - <para>If the <parameter>unset_environment</parameter> parameter is - non-zero, <function>sd_notify()</function> will unset the - <varname>$NOTIFY_SOCKET</varname> environment variable before - returning (regardless of whether the function call itself - succeeded or not). Further calls to - <function>sd_notify()</function> will then fail, but the variable - is no longer inherited by child processes.</para> - - <para>The <parameter>state</parameter> parameter should contain a - newline-separated list of variable assignments, similar in style - to an environment block. A trailing newline is implied if none is - specified. The string may contain any kind of variable - assignments, but the following shall be considered - well-known:</para> - - <variablelist> - <varlistentry> - <term>READY=1</term> - - <listitem><para>Tells the service manager that service startup - is finished. This is only used by systemd if the service - definition file has Type=notify set. Since there is little - value in signaling non-readiness, the only value services - should send is <literal>READY=1</literal> (i.e. - <literal>READY=0</literal> is not defined).</para></listitem> - </varlistentry> - - <varlistentry> - <term>RELOADING=1</term> - - <listitem><para>Tells the service manager that the service is - reloading its configuration. This is useful to allow the - service manager to track the service's internal state, and - present it to the user. Note that a service that sends this - notification must also send a <literal>READY=1</literal> - notification when it completed reloading its - configuration.</para></listitem> - </varlistentry> - - <varlistentry> - <term>STOPPING=1</term> - - <listitem><para>Tells the service manager that the service is - beginning its shutdown. This is useful to allow the service - manager to track the service's internal state, and present it - to the user.</para></listitem> - </varlistentry> - - <varlistentry> - <term>STATUS=...</term> - - <listitem><para>Passes a single-line UTF-8 status string back - to the service manager that describes the service state. This - is free-form and can be used for various purposes: general - state feedback, fsck-like programs could pass completion - percentages and failing programs could pass a human-readable - error message. Example: <literal>STATUS=Completed 66% of file - system check...</literal></para></listitem> - </varlistentry> - - <varlistentry> - <term>ERRNO=...</term> - - <listitem><para>If a service fails, the errno-style error - code, formatted as string. Example: <literal>ERRNO=2</literal> - for ENOENT.</para></listitem> - </varlistentry> - - <varlistentry> - <term>BUSERROR=...</term> - - <listitem><para>If a service fails, the D-Bus error-style - error code. Example: - <literal>BUSERROR=org.freedesktop.DBus.Error.TimedOut</literal></para></listitem> - </varlistentry> - - <varlistentry> - <term>MAINPID=...</term> - - <listitem><para>The main process ID (PID) of the service, in - case the service manager did not fork off the process itself. - Example: <literal>MAINPID=4711</literal></para></listitem> - </varlistentry> - - <varlistentry> - <term>WATCHDOG=1</term> - - <listitem><para>Tells the service manager to update the - watchdog timestamp. This is the keep-alive ping that services - need to issue in regular intervals if - <varname>WatchdogSec=</varname> is enabled for it. See - <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for information how to enable this functionality and - <citerefentry><refentrytitle>sd_watchdog_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry> - for the details of how the service can check whether the - watchdog is enabled. </para></listitem> - </varlistentry> - - - <varlistentry> - <term>FDSTORE=1</term> - - <listitem><para>Stores additional file descriptors in the service manager. File - descriptors sent this way will be maintained per-service by the service manager - and will be passed again using the usual file descriptor passing logic on the next - invocation of the service, see - <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>. - This is useful for implementing service restart schemes where services serialize - their state to <filename>/run</filename>, push their file descriptors to the - system manager, and are then restarted, retrieving their state again via socket - passing and <filename>/run</filename>. Note that the service manager will accept - messages for a service only if <varname>FileDescriptorStoreMax=</varname> is set - to non-zero for it (defaults to zero, see - <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>). - File descriptors must be pollable, see - <citerefentry><refentrytitle>epoll_ctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>. - Multiple arrays of file descriptors may be sent in separate messages, in which - case the arrays are combined. Note that the service manager removes duplicate - file descriptors before passing them to the service. Use - <function>sd_pid_notify_with_fds()</function> to send messages with - <literal>FDSTORE=1</literal>, see below.</para></listitem> - </varlistentry> - - <varlistentry> - <term>FDNAME=...</term> - - <listitem><para>When used in combination with - <varname>FDSTORE=1</varname>, specifies a name for the - submitted file descriptors. This name is passed to the service - during activation, and may be queried using - <citerefentry><refentrytitle>sd_listen_fds_with_names</refentrytitle><manvolnum>3</manvolnum></citerefentry>. File - descriptors submitted without this field set, will implicitly - get the name <literal>stored</literal> assigned. Note that, if - multiple file descriptors are submitted at once, the specified - name will be assigned to all of them. In order to assign - different names to submitted file descriptors, submit them in - separate invocations of - <function>sd_pid_notify_with_fds()</function>. The name may - consist of any ASCII character, but must not contain control - characters or <literal>:</literal>. It may not be longer than - 255 characters. If a submitted name does not follow these - restrictions, it is ignored.</para></listitem> - </varlistentry> - - <varlistentry> - <term>WATCHDOG_USEC=...</term> - - <listitem><para>Reset <varname>watchdog_usec</varname> value during runtime. - Notice that this is not available when using <function>sd_event_set_watchdog()</function> - or <function>sd_watchdog_enabled()</function>. - Example : <literal>WATCHDOG_USEC=20000000</literal></para></listitem> - </varlistentry> - - </variablelist> - - <para>It is recommended to prefix variable names that are not - listed above with <varname>X_</varname> to avoid namespace - clashes.</para> - - <para>Note that systemd will accept status data sent from a - service only if the <varname>NotifyAccess=</varname> option is - correctly set in the service definition file. See - <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for details.</para> - - <para><function>sd_notifyf()</function> is similar to - <function>sd_notify()</function> but takes a - <function>printf()</function>-like format string plus - arguments.</para> - - <para><function>sd_pid_notify()</function> and - <function>sd_pid_notifyf()</function> are similar to - <function>sd_notify()</function> and - <function>sd_notifyf()</function> but take a process ID (PID) to - use as originating PID for the message as first argument. This is - useful to send notification messages on behalf of other processes, - provided the appropriate privileges are available. If the PID - argument is specified as 0, the process ID of the calling process - is used, in which case the calls are fully equivalent to - <function>sd_notify()</function> and - <function>sd_notifyf()</function>.</para> - - <para><function>sd_pid_notify_with_fds()</function> is similar to - <function>sd_pid_notify()</function> but takes an additional array - of file descriptors. These file descriptors are sent along the - notification message to the service manager. This is particularly - useful for sending <literal>FDSTORE=1</literal> messages, as - described above. The additional arguments are a pointer to the - file descriptor array plus the number of file descriptors in the - array. If the number of file descriptors is passed as 0, the call - is fully equivalent to <function>sd_pid_notify()</function>, i.e. - no file descriptors are passed. Note that sending file descriptors - to the service manager on messages that do not expect them (i.e. - without <literal>FDSTORE=1</literal>) they are immediately closed - on reception.</para> - </refsect1> - - <refsect1> - <title>Return Value</title> - - <para>On failure, these calls return a negative errno-style error - code. If <varname>$NOTIFY_SOCKET</varname> was not set and hence - no status data could be sent, 0 is returned. If the status was - sent, these functions return with a positive return value. In - order to support both, init systems that implement this scheme and - those which do not, it is generally recommended to ignore the - return value of this call.</para> - </refsect1> - - <refsect1> - <title>Notes</title> - - <xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/> - - <para>These functions send a single datagram with the - state string as payload to the <constant>AF_UNIX</constant> socket - referenced in the <varname>$NOTIFY_SOCKET</varname> environment - variable. If the first character of - <varname>$NOTIFY_SOCKET</varname> is <literal>@</literal>, the - string is understood as Linux abstract namespace socket. The - datagram is accompanied by the process credentials of the sending - service, using SCM_CREDENTIALS.</para> - </refsect1> - - <refsect1> - <title>Environment</title> - - <variablelist class='environment-variables'> - <varlistentry> - <term><varname>$NOTIFY_SOCKET</varname></term> - - <listitem><para>Set by the service manager for supervised - processes for status and start-up completion notification. - This environment variable specifies the socket - <function>sd_notify()</function> talks to. See above for - details.</para></listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>Examples</title> - - <example> - <title>Start-up Notification</title> - - <para>When a service finished starting up, it might issue the - following call to notify the service manager:</para> - - <programlisting>sd_notify(0, "READY=1");</programlisting> - </example> - - <example> - <title>Extended Start-up Notification</title> - - <para>A service could send the following after completing - initialization:</para> - - <programlisting>sd_notifyf(0, "READY=1\n" - "STATUS=Processing requests...\n" - "MAINPID=%lu", - (unsigned long) getpid());</programlisting> - </example> - - <example> - <title>Error Cause Notification</title> - - <para>A service could send the following shortly before exiting, on failure:</para> - - <programlisting>sd_notifyf(0, "STATUS=Failed to start up: %s\n" - "ERRNO=%i", - strerror(errno), - errno);</programlisting> - </example> - - <example> - <title>Store a File Descriptor in the Service Manager</title> - - <para>To store an open file descriptor in the service manager, - in order to continue operation after a service restart without - losing state, use <literal>FDSTORE=1</literal>:</para> - - <programlisting>sd_pid_notify_with_fds(0, 0, "FDSTORE=1\nFDNAME=foobar", &fd, 1);</programlisting> - </example> - </refsect1> - - <refsect1> - <title>See Also</title> - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_listen_fds_with_names</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_watchdog_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |