source: general/sysutils/dbus-systemd.xml@ 7356a067

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;

  <!ENTITY dbus-download-http "http://dbus.freedesktop.org/releases/dbus/">
]>

<sect1 id="dbus" xreflabel="D-Bus">
  <?dbhtml filename="dbus.html"?>

  <sect1info>
    <othername>$LastChangedBy$</othername>
    <date>$Date$</date>
  </sect1info>

  <title>D-Bus</title>

  <indexterm zone="dbus">
    <primary sortas="a-D-Bus">D-Bus</primary>
  </indexterm>

  <sect2 role="package">
    <title>Introduction to D-Bus</title>

    <para>
      Even though <application>D-Bus</application> was built in
      LFS, there are some features provided by the package that
      some BLFS packages need, but their dependencies didn't fit
      into LFS.
    </para>

    <para>
      Unlike other packages in BLFS, there is no set version of
      <application>D-Bus</application> in this page's title and
      no set version specified for download. Version updates to
      <application>D-Bus</application> make it possible that the
      user's system may have a <application>D-Bus</application>
      version different from the one in the current LFS book.
      Therefore, users should use the version of
      <application>D-Bus</application> that is currently
      installed on their system.
    </para>

    <bridgehead renderas="sect3">Package Information</bridgehead>
    <itemizedlist spacing="compact">
      <listitem>
        <para>
          Download (HTTP): <ulink url="&dbus-download-http;"/>
        </para>
      </listitem>
    </itemizedlist>

    <note>
      <para>
        If you are unsure which version needs to be downloaded, issue
        <command>dbus-daemon --version</command> in order to find out.
        Some of the commands below might need the version information.
        Issue the following command to store the
        <application>D-Bus</application> version number into an
        environment variable:
      </para>

<screen><userinput>export DBUS_VERSION=$(dbus-daemon --version | head -n1 | awk '{print $5})</userinput></screen>
    </note>

    <bridgehead renderas="sect3">D-Bus Dependencies</bridgehead>

    <bridgehead renderas="sect4">Required</bridgehead>
    <para role="required">
      <xref linkend="xorg7-lib"/> (for X11 autolaunch support)
    </para>

    <bridgehead renderas="sect4">Optional</bridgehead>
    <para role="optional">
      For the tests:
      <xref linkend="dbus-glib"/>,
      <xref linkend="dbus-python"/>, and
      <xref linkend="pygobject2"/>;
      for the API documentation:
      <xref linkend="doxygen"/>; 
      for man pages and XML/HTML documentation:
      <xref linkend="xmlto"/>
    </para>

    <para condition="html" role="usernotes">User Notes:
      <ulink url="&blfs-wiki;/dbus"/>
    </para>
  </sect2>

  <sect2 role="installation">
    <title>Installation of D-Bus</title>

    <para>
      Rebuild <application>D-Bus</application> by running the
      following commands:
    </para>

<screen><userinput>./configure --prefix=/usr                        \
            --sysconfdir=/etc                    \
            --localstatedir=/var                 \
            --with-console-auth-dir=/run/console \
            --docdir=/usr/share/doc/dbus-${DBUS_VERSION} &amp;&amp;
make</userinput></screen>

    <para>
      See below for test instructions.
    </para>

    <warning>
      <para>
        Installing the package will override all files installed by
        <application>D-Bus</application> in LFS. It is critical that
        nothing uses <application>D-Bus</application> libraries or
        programs during the installation phrase. Best way to achieve
        that is to do the installation in the rescue mode. To switch
        to the rescue mode, issue the following command as the
        <systemitem class="username">root</systemitem> user from a TTY:
      </para>

<screen role="root"><userinput>systemctl start rescue.target</userinput></screen>
    </warning>

    <para>
      Now, as the <systemitem class="username">root</systemitem> user:
    </para>

<screen role="root"><userinput>make install</userinput></screen>

    <para>
      The shared library needs to be moved to
      <filename class="directory">/lib</filename>, and as a result the
      <filename class="extension">.so</filename> file in
      <filename class="directory">/usr/lib</filename> will need to be
      recreated. Run the following command as the
      <systemitem class="username">root</systemitem> user:
    </para>

<screen><userinput remap="install">mv -v /usr/lib/libdbus-1.so.* /lib
ln -sfv ../../lib/$(readlink /usr/lib/libdbus-1.so) /usr/lib/libdbus-1.so</userinput></screen>

    <para>
      The <application>D-Bus</application> tests cannot be run until after
      <xref linkend="dbus-glib"/> has been installed.  They must be run as
      an unprivileged user from a local session. If you want to run only
      the unit tests, replace <parameter>--enable-tests</parameter> in the
      command below by <parameter>--enable-embedded-tests</parameter>,
      otherwise <xref linkend="dbus-python"/> has to be installed before
      the tests are run. The tests require passing additional parameters to
      <command>configure</command> and exposing additional functionality in
      the binaries. These interfaces are not intended to be used in a
      production build of <application>D-Bus</application>. If you would
      like to run the tests, issue the following commands:
    </para>

<screen><userinput>make distclean                              &amp;&amp;
./configure --enable-tests --enable-asserts &amp;&amp;
make                                        &amp;&amp;
make check                                  &amp;&amp;
make distclean</userinput></screen>

    <para>
      If <command>run-test.sh</command> fails, it can be disabled with the
      following sed, before running the commands for the tests:
    </para>

<screen><userinput>sed -i -e 's:run-test.sh:$(NULL):g' test/name-test/Makefile.in</userinput></screen>

    <para>
      Note there has been a report that the tests may fail if running
      inside a Midnight Commander shell.
      You may get out-of-memory error messages when running the tests.
      These are normal and can be safely ignored.
    </para>

  </sect2>

  <sect2 role="commands">
    <title>Command Explanations</title>

    <para>
      <parameter>--enable-tests</parameter>: Build extra parts of the code to
      support all tests. Configure will end with a NOTE warning about increased
      size of libraries and decreased security.
    </para>

    <para>
      <parameter>--enable-embedded-tests</parameter>: Build extra parts of the
      code to support only unit tests. Configure will end with a NOTE warning
      about increased size of libraries and decreased security.
    </para>

    <para>
      <parameter>--enable-asserts</parameter>: Enable debugging code to run
      assertions for statements normally assumed to be true. This prevents a
      warning that '<parameter>--enable-tests</parameter>' on its own is only
      useful for profiling and might not give true results for all tests, but
      adds its own NOTE that this should not be used in a production build.
    </para>

  </sect2>

  <sect2 role="configuration">
    <title>Configuring D-Bus</title>

    <sect3 id="dbus-config">
      <title>Config Files</title>

      <para>
        <filename>/etc/dbus-1/session.conf</filename>,
        <filename>/etc/dbus-1/system.conf</filename> and
        <filename>/etc/dbus-1/system.d/*</filename>
      </para>

      <indexterm zone="dbus dbus-config">
        <primary sortas="e-etc-dbus-1-session.conf">/etc/dbus-1/session.conf</primary>
      </indexterm>

      <indexterm zone="dbus dbus-config">
        <primary sortas="e-etc-dbus-1/system.conf">/etc/dbus-1/system.conf</primary>
      </indexterm>

      <indexterm zone="dbus dbus-config">
        <primary sortas="e-etc-dbus-1-system.d-star">/etc/dbus-1/system.d/*</primary>
      </indexterm>

    </sect3>

    <sect3 id="dbus-session-config" xreflabel="D-Bus custom services directory">
      <title>Configuration Information</title>

      <para>
        The configuration files listed above should probably not be
        modified. If changes are required, you should create
        <filename>/etc/dbus-1/session-local.conf</filename> and/or
        <filename>/etc/dbus-1/system-local.conf</filename> and make any
        desired changes to these files.
     </para>

      <para>
        If any packages install a
        <application>D-Bus</application> <filename>.service</filename>
        file outside of the standard <filename
        class="directory">/usr/share/dbus-1/services</filename> directory,
        that directory should be added to the local session configuration.
        For instance, <filename
        class="directory">/usr/local/share/dbus-1/services</filename> can
        be added by performing the following commands as the
        <systemitem class="username">root</systemitem> user:
      </para>

<screen role="root"><userinput>cat &gt; /etc/dbus-1/session-local.conf &lt;&lt; "EOF"
<literal>&lt;!DOCTYPE busconfig PUBLIC
 "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd"&gt;
&lt;busconfig&gt;

  &lt;!-- Search for .service files in /usr/local --&gt;
  &lt;servicedir&gt;/usr/local/share/dbus-1/services&lt;/servicedir&gt;

&lt;/busconfig&gt;</literal>
EOF</userinput></screen>

    </sect3>

    <sect3  id="dbus-session">
      <title>D-Bus Session Daemon</title>

      <para>
        There are many methods you can use to start a session daemon
        using the <command>dbus-launch</command> command. Review the
        <command>dbus-launch</command> man page for details about the
        available parameters and options. Here are some suggestions and
        examples:
      </para>

      <itemizedlist spacing="compact">
        <listitem>
          <para>
            Add <command>dbus-launch</command> to the line in the
            <filename>~/.xinitrc</filename> file that starts your graphical
            desktop environment.
          </para>
        </listitem>
        <listitem>
          <para>
            If you use <command>xdm</command> or some other display manager
            that calls the <filename>~/.xsession</filename> file, you can add
            <command>dbus-launch</command> to the line in your
            <filename>~/.xsession</filename> file that starts your graphical
            desktop environment. The syntax would be similar to the example in
            the <filename>~/.xinitrc</filename> file.
          </para>
        </listitem>
        <listitem>
          <para>
            The examples shown previously use
            <command>dbus-launch</command> to specify a program to be run. This
            has the benefit (when also using the
            <parameter>--exit-with-session</parameter> parameter) of stopping the
            session daemon when the specified program is stopped. You can also
            start the session daemon in your system or personal startup scripts
            by adding the following lines:
          </para>

<screen><userinput><literal># Start the D-Bus session daemon
eval `dbus-launch`
export DBUS_SESSION_BUS_ADDRESS</literal></userinput></screen>

          <para>
            This method will not stop the session daemon when you exit
            your shell, therefore you should add the following line to your
            <filename>~/.bash_logout</filename> file:
          </para>

<screen><userinput><literal># Kill the D-Bus session daemon
kill $DBUS_SESSION_BUS_PID</literal></userinput></screen>
        </listitem>

        <listitem>
          <para>
            A hint has been written that provides ways to start scripts
            using the KDM session manager of KDE. The concepts in this hint could
            possibly be used with other session managers as well. The hint is
            located at <ulink
            url="&hints-root;/downloads/files/execute-session-scripts-using-kdm.txt"/>.
          </para>
        </listitem>

      </itemizedlist>

    </sect3>

  </sect2>

  <sect2 role="content">
    <title>Contents</title>

      <para>
        A list of the installed files, along with their short
        descriptions can be found at
        <ulink url="http://www.linuxfromscratch.org/lfs/view/systemd/chapter06/dbus.html#contents-dbus"/>.
      </para>

  </sect2>

</sect1>