chiark / gitweb /
socket: add support for tcp nagle
[elogind.git] / man / sysusers.d.xml
index 549b3f6351eae3c3bf8019cdd25500e7699f6d07..58f24a62f5f80d060713db302ea2f8016a5784d5 100644 (file)
                 <title>Description</title>
 
                 <para><command>systemd-sysusers</command> uses the
                 <title>Description</title>
 
                 <para><command>systemd-sysusers</command> uses the
-                files from <filename>/usr/lib/sysusers.d/</filename>
+                files from <filename>sysusers.d</filename> directory
                 to create system users and groups at package
                 to create system users and groups at package
-                installation or boot time. This tool may be used for
-                allocating system users and groups only, it is not
+                installation or boot time. This tool may be used to
+                allocate system users and groups only, it is not
                 useful for creating non-system users and groups, as it
                 useful for creating non-system users and groups, as it
-                accessed <filename>/etc/passwd</filename> and
+                accesses <filename>/etc/passwd</filename> and
                 <filename>/etc/group</filename> directly, bypassing
                 <filename>/etc/group</filename> directly, bypassing
-                any more complex user database, for example any
+                any more complex user databases, for example any
                 database involving NIS or LDAP.</para>
                 database involving NIS or LDAP.</para>
-
         </refsect1>
 
         <refsect1>
         </refsect1>
 
         <refsect1>
-                <title>File Format</title>
-
-                <para>Each file shall be named in the style of
-                <filename><replaceable>package</replaceable>.conf</filename>.</para>
+                <title>Configuration Format</title>
 
 
-                <para>All files are sorted by their filename in
-                lexicographic order, regardless of which of the
-                directories they reside in. If multiple files specify
-                the same user or group, the entry in the file with the
-                lexicographically earliest name will be applied, all
-                all other conflicting entries will be logged as
-                errors. Users and groups are
-                processed in the order they are listed.</para>
+                <para>Each configuration file shall be named in the
+                style of
+                <filename><replaceable>package</replaceable>.conf</filename>
+                or
+                <filename><replaceable>package</replaceable>-<replaceable>part</replaceable>.conf</filename>.
+                The second variant should be used when it is desirable
+                to make it easy to override just this part of
+                configuration.</para>
 
                 <para>The file format is one line per user or group
                 containing name, ID and GECOS field description:</para>
 
                 <para>The file format is one line per user or group
                 containing name, ID and GECOS field description:</para>
@@ -106,7 +102,7 @@ m authd input</programlisting>
                                         group will be set to the group
                                         bearing the same name. The
                                         user's shell will be set to
                                         group will be set to the group
                                         bearing the same name. The
                                         user's shell will be set to
-                                        <filename>/sbin/login</filename>,
+                                        <filename>/sbin/nologin</filename>,
                                         the home directory to
                                         <filename>/</filename>. The
                                         account will be created
                                         the home directory to
                                         <filename>/</filename>. The
                                         account will be created
@@ -142,7 +138,7 @@ m authd input</programlisting>
                         <title>Name</title>
 
                         <para>The name field specifies the user or
                         <title>Name</title>
 
                         <para>The name field specifies the user or
-                        group name. It should be be shorter than 256
+                        group name. It should be shorter than 31
                         characters and avoid any non-ASCII characters,
                         and not begin with a numeric character. It is
                         strongly recommended to pick user and group
                         characters and avoid any non-ASCII characters,
                         and not begin with a numeric character. It is
                         strongly recommended to pick user and group
@@ -192,11 +188,40 @@ m authd input</programlisting>
 
         </refsect1>
 
 
         </refsect1>
 
+        <refsect1>
+                <title>Overriding vendor configuration</title>
+
+                <para>Note that <command>systemd-sysusers</command>
+                will do nothing if the specified users or groups
+                already exist, so normally there no reason to override
+                <filename>sysusers.d</filename> vendor configuration,
+                except to block certain users or groups from being
+                created.</para>
+
+                <para>Files in <filename>/etc/sysusers.d</filename>
+                override files with the same name in
+                <filename>/usr/lib/sysusers.d</filename> and
+                <filename>/run/sysusers.d</filename>. Files in
+                <filename>/run/sysusers.d</filename> override files
+                with the same name in
+                <filename>/usr/lib/sysusers.d</filename>. The scheme is the same as for
+                <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                except for the directory name.</para>
+
+                <para>If the administrator wants to disable a
+                configuration file supplied by the vendor, the
+                recommended way is to place a symlink to
+                <filename>/dev/null</filename> in
+                <filename>/etc/sysusers.d/</filename> bearing the
+                same filename.</para>
+        </refsect1>
+
         <refsect1>
                 <title>See Also</title>
                 <para>
                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
         <refsect1>
                 <title>See Also</title>
                 <para>
                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
-                        <citerefentry><refentrytitle>systemd-sysusers</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+                        <citerefentry><refentrytitle>systemd-sysusers</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                 </para>
         </refsect1>
 
                 </para>
         </refsect1>