man: add a systemd-rc-local-generator(8) man page

Most importantly, let's highlight the differences to the rc-local
behaviour in SysV.

Fixes: #7703

4 files changed, 89 insertions, 0 deletions

diff --git a/man/rules/meson.build b/man/rules/meson.build
index 499fe6d19e..54c5a9d923 100644
--- a/man/rules/meson.build
+++ b/man/rules/meson.build
@@ -594,6 +594,7 @@ manpages = [
   '8',
   ['systemd-random-seed'],
   'ENABLE_RANDOMSEED'],
+ ['systemd-rc-local-generator', '8', [], ''],
  ['systemd-remount-fs.service', '8', ['systemd-remount-fs'], ''],
  ['systemd-resolve', '1', [], 'ENABLE_RESOLVE'],
  ['systemd-resolved.service', '8', ['systemd-resolved'], 'ENABLE_RESOLVE'],
diff --git a/man/systemd-rc-local-generator.xml b/man/systemd-rc-local-generator.xml
new file mode 100644
index 0000000000..89cd7ec614
--- /dev/null
+++ b/man/systemd-rc-local-generator.xml
@@ -0,0 +1,86 @@
+<?xml version="1.0"?>
+<!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+  SPDX-License-Identifier: LGPL-2.1+
+
+  This file is part of systemd.
+
+  Copyright 2017 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="systemd-rc-local-generator">
+
+  <refentryinfo>
+    <title>systemd-rc-local-generator</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>systemd-rc-local-generator</refentrytitle>
+    <manvolnum>8</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>systemd-rc-local-generator</refname>
+    <refpurpose>Compatibility generator for starting <filename>/etc/rc.local</filename> and <filename>/usr/sbin/halt.local</filename> during boot and shutdown</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <para><filename>/usr/lib/systemd/system-generators/systemd-rc-local-generator</filename></para>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><filename>systemd-rc-local-generator</filename> is a generator that checks whether
+    <filename>/etc/rc.local</filename> exists and is executable, and if it is pulls the
+    <filename>rc-local.service</filename> unit into the boot process. This unit is responsible for running this script
+    during late boot. Note that the script will be run with slightly different semantics than the original System V
+    version, which was run "last" in the boot process, which is a concept that does not translate to systemd. The
+    script is run after <filename>network.target</filename>, but in parallel with most other regular system
+    services.</para>
+
+    <para><filename>systemd-rc-local-generator</filename> also checks whether <filename>/usr/sbin/halt.local</filename>
+    exists and is executable, and if it is pulls the <filename>halt-local.service</filename> unit into the shutdown
+    process. This unit is responsible for running this script during later shutdown.</para>
+
+    <para>Support for both <filename>/etc/rc.local</filename> and <filename>/usr/sbin/halt.local</filename> is provided
+    for compatibility with specific System V systems only. However, it is strongly recommended to avoid making use of
+    these scripts today, and instead provide proper unit files with appropriate dependencies for any scripts to run
+    during the boot or shutdown processes.</para>
+
+    <para><filename>systemd-rc-local-generator</filename> implements
+    <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>
diff --git a/man/systemd.generator.xml b/man/systemd.generator.xml
index 55bb2b4a90..5e25bb776d 100644
--- a/man/systemd.generator.xml
+++ b/man/systemd.generator.xml
@@ -336,6 +336,7 @@ find $dir</programlisting>
       <citerefentry><refentrytitle>systemd-getty-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemd-rc-local-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-system-update-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-sysv-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
diff --git a/units/rc-local.service.in b/units/rc-local.service.in
index 5dbd62aecb..78ce69e0ae 100644
--- a/units/rc-local.service.in
+++ b/units/rc-local.service.in
@@ -11,6 +11,7 @@
 # systemd-rc-local-generator if @RC_LOCAL_SCRIPT_PATH_START@ is executable.
 [Unit]
 Description=@RC_LOCAL_SCRIPT_PATH_START@ Compatibility
+Documentation=man:systemd-rc-local-generator(8)
 ConditionFileIsExecutable=@RC_LOCAL_SCRIPT_PATH_START@
 After=network.target