man/standard-conf.xml

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   8 <refsection>
   9   <refsection id='confd'>
  10     <title>Configuration Directories and Precedence</title>
  11
  12     <para>Configuration files are read from directories in
  13     <filename>/etc/</filename>, <filename>/run/</filename>, and
  14     <filename>/usr/lib/</filename>, in order of precedence.
  15     Each configuration file in these configuration directories shall be named in
  16     the style of <filename><replaceable>filename</replaceable>.conf</filename>.
  17     Files in <filename>/etc/</filename> override files with the same name in
  18     <filename>/run/</filename> and <filename>/usr/lib/</filename>. Files in
  19     <filename>/run/</filename> override files with the same name in
  20     <filename>/usr/lib/</filename>.</para>
  21
  22     <para>Packages should install their configuration files in
  23     <filename>/usr/lib/</filename>. Files in <filename>/etc/</filename> are
  24     reserved for the local administrator, who may use this logic to override the
  25     configuration files installed by vendor packages. All configuration files
  26     are sorted by their filename in lexicographic order, regardless of which of
  27     the directories they reside in. If multiple files specify the same option,
  28     the entry in the file with the lexicographically latest name will take
  29     precedence. It is recommended to prefix all filenames with a two-digit number
  30     and a dash, to simplify the ordering of the files.</para>
  31
  32     <para>If the administrator wants to disable a configuration file supplied by
  33     the vendor, the recommended way is to place a symlink to
  34     <filename>/dev/null</filename> in the configuration directory in
  35     <filename>/etc/</filename>, with the same filename as the vendor
  36     configuration file.</para>
  37   </refsection>
  38
  39   <refsection id='main-conf'>
  40     <title>Configuration Directories and Precedence</title>
  41
  42     <para>Default configuration is defined during compilation, so a
  43     configuration file is only needed when it is necessary to deviate
  44     from those defaults. By default the configuration file in
  45     <filename>&pkgsysconfdir;/</filename> contains commented out entries
  46     showing the defaults as a guide to the administrator. This file
  47     can be edited to create local overrides.
  48     </para>
  49
  50     <para>When packages need to customize the configuration, they can
  51     install configuration snippets in
  52     <filename>&rootlibexecdir;/*.conf.d/</filename>. Files in
  53     <filename>/etc/</filename> are reserved for the local
  54     administrator, who may use this logic to override the
  55     configuration files installed by vendor packages. The main
  56     configuration file is read before any of the configuration
  57     directories, and has the lowest precedence; entries in a file in
  58     any configuration directory override entries in the single
  59     configuration file. Files in the
  60     <filename>*.conf.d/</filename> configuration subdirectories
  61     are sorted by their filename in lexicographic order, regardless of
  62     which of the subdirectories they reside in. If multiple files
  63     specify the same option, the entry in the file with the
  64     lexicographically latest name takes precedence.  It is recommended
  65     to prefix all filenames in those subdirectories with a two-digit
  66     number and a dash, to simplify the ordering of the files.</para>
  67
  68     <para>To disable a configuration file supplied by the vendor, the
  69     recommended way is to place a symlink to
  70     <filename>/dev/null</filename> in the configuration directory in
  71     <filename>/etc/</filename>, with the same filename as the vendor
  72     configuration file.</para>
  73   </refsection>
  74 </refsection>