httpd/httpd.conf.xml

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<refentry>
  <refentryinfo>
    <title>httpd.conf</title>
    <productname>httpd</productname>
    <author><contrib>Author</contrib><surname>Orton</surname><firstname>Joe</firstname><email>jorton@redhat.com</email></author>
  </refentryinfo>

  <refmeta>
    <refentrytitle>httpd.conf</refentrytitle>
    <manvolnum>5</manvolnum>
  </refmeta>
  
  <refnamediv>
    <refname>httpd.conf</refname>
    <refpurpose>Configuration files for httpd</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para>
      <filename>/etc/httpd/conf/httpd.conf</filename>, 
      <filename>/etc/httpd/conf.modules.d</filename>,
      <filename>/etc/httpd/conf.d</filename>
    </para>
  </refsynopsisdiv>
  
  <refsect1>
    <title>Description</title>

    <para>The main configuration file for the <command>httpd</command> daemon is
    <filename>/etc/httpd/conf/httpd.conf</filename>.  The syntax of
    this file is described at <ulink
    url="https://httpd.apache.org/docs/2.4/configuring.html"/>, and
    the full set of available directives is listed at <ulink
    url="https://httpd.apache.org/docs/2.4/mod/directives.html"/>.
    </para>

    <refsect2>
      <title>Configuration structure</title>

      <para>The main configuration file
      (<filename>httpd.conf</filename>) sets up various defaults and
      includes configuration files from two directories -
      <filename>/etc/httpd/conf.modules.d</filename> and
      <filename>/etc/httpd/conf.d</filename>.  Packages containing
      loadable modules (like <option>mod_ssl.so</option>) place files
      in the <filename>conf.modules.d</filename> directory with the
      appropriate <option>LoadModule</option> directive so that module
      is loaded by default.</para>

      <para>Some notable configured defaults are:</para>

      <variablelist>
        <varlistentry>
          <term><option>DocumentRoot @DOCROOT@/html</option></term>
          <listitem><para>The default document root from which content
          is served.</para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>Listen 80</option></term>
          <listitem><para>The daemon listens on TCP port 80.</para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>ErrorLog "logs/error_log"</option></term>
          <listitem><para>Error messages are logged to
          <filename>@LOGDIR@/error_log</filename>.</para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>ScriptAlias /cgi-bin/ "@DOCROOT@/cgi-bin/"</option></term>
          <listitem><para>CGI scripts are served via the URL-path <option>/cgi-bin/</option>.</para></listitem>
        </varlistentry>
        
      </variablelist>

      <para>To remove any of the default configuration provided in
      separate files covered below, replace that file with an empty
      file rather than removing it from the filesystem, otherwise it
      may be restored to the original when the package which provides
      it is upgraded.</para>
      
    </refsect2>

    <refsect2>
      <title>MPM configuration</title>

      <para>The configuration file at
      <filename>/etc/httpd/conf.modules.d/00-mpm.conf</filename> is
      used to select the multi-processing module (MPM), which governs
      how <command>httpd</command> divides work between processes
      and/or threads at run-time.  Exactly one
      <option>LoadModule</option> directive must be uncommented in
      this file; by default the <option>@MPM@</option> MPM is enabled.
      For more information on MPMs, see <ulink
      url="https://httpd.apache.org/docs/2.4/mpm.html"/>.</para>

      <para>If using the <emphasis>prefork</emphasis> MPM, the
      "httpd_graceful_shutdown" SELinux boolean should also be
      enabled, since with this MPM, httpd needs to establish TCP
      connections to local ports to successfully complete a graceful
      restart or shutdown. This boolean can be enabled by running the
      command: <command>semanage boolean -m --on
      httpd_graceful_shutdown</command></para>
    </refsect2>
    
    <refsect2>
      <title>Module configuration files</title>
      
      <para>Module configuration files are provided in the
      <filename>/etc/httpd/conf.modules.d/</filename> directory.
      Filenames in this directory are by convention prefixed with two
      digit numeric prefix to ensure they are processed in the desired
      order.  Core modules provided with the <command>httpd</command>
      package are loaded by files with a <option>0x-</option> prefix
      to ensure these load first.  Only filenames with a
      <option>.conf</option> suffix in this directory will be
      processed.</para>

      <para>Other provided configuration files are listed below.
      
      <variablelist>
        <varlistentry>
          <term><filename>/etc/httpd/conf.modules.d/00-base.conf</filename></term>
          <listitem><para>The set of core modules included with
          <command>httpd</command> which are all loaded by
          default.</para></listitem>
        </varlistentry>
        
        <varlistentry>
          <term><filename>/etc/httpd/conf.modules.d/00-optional.conf</filename></term>
          <listitem><para>The set of non-core modules included with
          <command>httpd</command> which are <emphasis>not</emphasis>
          loaded by default.</para></listitem>
        </varlistentry>
        

        <varlistentry>
          <term><filename>/etc/httpd/conf.modules.d/00-systemd.conf</filename></term>
          <listitem><para>This file loads <option>mod_systemd</option>
          which is necessary for the correct operation of the
          <command>httpd.service</command> systemd unit, and should
          not be removed or disabled.</para></listitem>
        </varlistentry>
      </variablelist>
      </para>
    </refsect2>
        
    <refsect2>
      <title>Other configuration files</title>

      <para>Default module configuration files and site-specific
      configuration files are loaded from the
      <filename>/etc/httpd/conf.d/</filename> directory.  Only files
      with a <option>.conf</option> suffix will be loaded.  The
      following files are provided:

      <variablelist>
        <varlistentry>
          <term><filename>/etc/httpd/conf.d/userdir.conf</filename></term>
          <listitem><para>This file gives an example configuration for
          <option>mod_userdir</option> to map URLs such as
          <option>http://localhost/~jim/</option> to
          <filename>/home/jim/public_html/</filename>. Userdir mapping
          is disabled by default.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><filename>/etc/httpd/conf.d/autoindex.conf</filename></term>
          <listitem><para>This file provides the default configuration
          for <option>mod_autoindex</option> which generates HTML
          directory listings when enabled.  It also makes file icon
          image files available at the <option>/icons/</option>
          URL-path.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><filename>/etc/httpd/conf.d/welcome.conf</filename></term>
          <listitem><para>This file enables a "welcome page" at
          <option>http://localhost/</option> if no content is present
          in the default documentation root
          <filename>/var/www/html</filename>.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><filename>/etc/httpd/conf.d/ssl.conf</filename> (present only if <option>mod_ssl</option> is installed)</term>
          <listitem><para>This file configures a TLS
          <option>VirtualHost</option> listening on port
          <option>443</option>.  If the default configuration is used,
          the referenced test certificate and private key are
          generated the first time <command>httpd.service</command> is
          started; see
          <citerefentry><refentrytitle>httpd-init.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
          for more information.</para></listitem>
        </varlistentry>
        
      </variablelist></para>
    </refsect2>
    
    <refsect2>
      <title>Instantiated services</title>

      <para>As an alternative to (or in addition to) the
      <command>httpd.service</command> unit, the instantiated template
      service <command>httpd@.service</command> unit file can be used,
      which starts <command>httpd</command> using a different
      configuration file to the default. For example,
      <command>systemctl start httpd@foobar.service</command> will
      start httpd using the configuration file
      <filename>/etc/httpd/conf/foobar.conf</filename>.  See <citerefentry><refentrytitle>httpd@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> for more information.</para>
    </refsect2>
      
  </refsect1>
  <refsect1>
    <title>Files</title>

    <para>
      <filename>/etc/httpd/conf/httpd.conf</filename>, 
      <filename>/etc/httpd/conf.d</filename>, 
      <filename>/etc/httpd/conf.modules.d</filename>
    </para>
  </refsect1>
  
  <refsect1>
    <title>See also</title>

    <para>
    <citerefentry><refentrytitle>httpd</refentrytitle><manvolnum>8</manvolnum></citerefentry>, 
    <citerefentry><refentrytitle>httpd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
    <ulink url="https://httpd.apache.org/docs/2.4/configuring.html"/>,
    <ulink url="https://httpd.apache.org/docs/2.4/mod/directives.html"/>
    </para>
  </refsect1>

</refentry>

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