Blame Manuals/Tcar-ug/Repository/Workstation/config.docbook

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<sect1 id="repo-ws-config">
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    <title>Configuring Your Workstation</title>
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    <para>
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        Once your worstation is installed, it is time for you to
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        configure it.  At this point you create a user for everyday's
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        work, configure third party repositories, fix environment
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        variables to fit your personal needs, download the working
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        copy of &TCAR; and prepare it for start using it.
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    </para>
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    <sect2 id="repo-ws-config-wp">
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    <title>Workplace</title>
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    <para>
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        Once you've installed the workstation and it is up and
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        running, you need to create the user name you'll use for your
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        everyday's work. In this task you need to use the commands
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        <command>useradd</command> and <command>passwd</command> to
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        create the user name and set a password for it, respectively.
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        These commands require administrative privileges to be
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        executed, so you need to login as <emphasis>root</emphasis>
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        superuser for doing so. 
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    </para>
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    <caution>
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    <para>
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        Do not use the <emphasis>root</emphasis> username for your
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        everyday's work inside your working copy of &TCAR;.  This is
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        dangerous and might provoke unreversable damages on your
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        workstation.
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    </para>
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    </caution>
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    <para>
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        When user names are created inside the workstation, it doesn't
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        create only a user identifier for you to login, but a place
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        for you to store your information, as well. This place is
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        known as your home directory and is unique for each user
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        inside the workstation.  At the moment, we face the following
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        design problems related to handling absolute paths inside the
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        working copies of &TCAR;:
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    </para>
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    <variablelist>
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    <varlistentry>
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    <term>Case 1: Different home directories</term>
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    <listitem>
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    <para>
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        Assuming you store your working copy under 
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        class="directory">/home/john/artwork/</filename> and I store
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        mine under 
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        class="directory">/home/al/artwork/</filename>, we'll end up
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        refering the same files inside our working copies through
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        different absolute paths. This generates a contradiction when
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        files, holding path information inside, are committed up to
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        the central repository. The contradiction comes from the
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        question: which is the correct absolute path to use inside
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        such files, yours or mine? — No one of them is, of
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        course.
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    </para>
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    </listitem>
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    </varlistentry>
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    <varlistentry>
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    <term>Case 2: One unique home directory</term>
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    <listitem>
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    <para>
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        Another case would be that you and I ourselves use one unique
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        home directory (e.g., 
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        class="directory">/home/centos/artwork/</filename>) to store
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        the working copy of &TCAR; in our own workstations, but
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        configure the subversion client to use different user names to
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        commit changes up from the working copy to the central
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        repository.  This configuration might be not so good for
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        situations where you and I have to share the same workstation.
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        In such case, it would be required that we both share the
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        password information of the same system user (the
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        <emphasis>centos</emphasis> user in our example) which, in
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        addition, gives access to that user's subversion client
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        configuration and this way provokes the whole sense of using
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        different subversion credentials for committing changes to be
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        lost.
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    </para>
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    </listitem>
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    </varlistentry>
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    <varlistentry>
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    <term>Case 3: Different home directories through dynamic expansion</term>
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    <listitem>
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    <para>
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        Most of the absolute paths we use inside the working copy are
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        made of two parts, one dynamic and one fixed. The dynamic part
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        is the home directory of the current user and its value can be
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        retrived from the <envar>$HOME</envar> environment variable.
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        The fixed part of the path is the one we set inside the
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        repositroy structure itself as organization matter.  What we
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        need here is to find a way to expand variables inside files
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        that don't support variable expansion.  So far we've been
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        doing this through creation template instances which are
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        temporal files with translation markers expanded inside.  This
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        work rather fine with template files that are one-time-pass
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        (e.g., when we produce produce PNG files from SVG files and
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        XTHML from DocBook files), but the same is not true for
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        absolute paths inside files that are used as in their
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        permanent state inside the repository (e.g., CSS files and
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        other files similar in purpose).
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    </para>
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    </listitem>
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    </varlistentry>
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    </variablelist>
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    <para>
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        From the three cases discussed above, the second one (i.e.,
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        One unique home directory) seems to be the best candidate. It
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        limits us from using more than one working copy in the same
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        workstation, but gives us the chance of standardizing the use
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        of absolute paths inside all the working copies of &TCAR;.
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        Using absolute paths is very convenient because it is possible
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        to reuse information from different locations inside the
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        working copy, something that would be almost imposible to
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        maintain if relative paths were used instead. Thus, lets
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        assume the second case of handling home directories as default
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        solution to relatively solve the problem of where to store
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        working copies of &TCAR; until a better one shows itself up.
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    </para>
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    <para>
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        The action of providing working copies of &TCAR; that permit
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        to reuse files inside them unifies the way content is produced
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        inside the working copy and provides a convenction for people
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        working on different areas to get attached to in order to
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        syncronize their works and still keep doing it decentralized
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        one another.
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    </para>
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    </sect2>
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    <sect2 id="repo-ws-config-envar">
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    <title>Environment Variables</title>
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    <para>
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        Once you've created the <emphasis>centos</emphasis> user name
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        for your everyday's work and you had done login with it, there
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        are some environment variables that you can customize to fit
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        your personal needs (e.g., default text editor, default locale
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        information, default time zone representation, etc.).  To
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        customize these variables you need to edit your personal
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        profile (i.e., 
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        class="directory">~/.bash_profile</filename>) and set the
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        redefinition there.  Notice that you may need to logout and
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        then do login again in order for the new variable values to
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        take effect.
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    </para>
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    <variablelist>
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    <varlistentry>
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    <term>Default text editor</term>
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    <listitem>
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    <para>
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        The default text editor information is controlled by the
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        <envar>EDITOR</envar> environment variable. The
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        <command>centos-art.sh</command> script uses the default text
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        editor to edit subversion pre-commit messages, translation
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        files, documentation files, script files, and similar
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        text-based files.
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    </para>
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    <para>
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        If <envar>EDITOR</envar> environment variable is not set,
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        <command>centos-art.sh</command> script uses 
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        class="directory">/usr/bin/vim</filename> as default text
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        editor. Otherwise, the following values are recognized by
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        <command>centos-art.sh</command> script:
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        <itemizedlist>
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        <listitem>
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        <para>
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            <filename class="directory">/usr/bin/vim</filename>
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        </para>
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        </listitem>
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        <listitem>
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        <para>
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        <filename class="directory">/usr/bin/emacs</filename>
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        </para>
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        </listitem>
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        <listitem>
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        <para>
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            <filename class="directory">/usr/bin/nano</filename>
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        </para>
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        </listitem>
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        </itemizedlist>
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    </para>
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    <para>
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        If no one of these values is set in the <envar>EDITOR</envar>
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        environment variable, the <command>centos-art.sh</command>
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        script uses 
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        class="directory">/usr/bin/vim</filename> text editor, the one
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        installed by default in &TC;;. 
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    </para>
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    </listitem>
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    </varlistentry>
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    <varlistentry>
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    <term>Default locale information</term>
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    <listitem>
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    <para>
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        The default locale information is controlled by the
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        <envar>LANG</envar> environment variable. This variable is
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        initially set in the installation process of &TC;;,
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        specifically in the <emphasis>Language</emphasis> step.
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        Generally, there is no need to customize this variable in your
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        personal profile. If you need to change the value of this
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        environment variable do it through the login screen of GNOME
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        Desktop Environment or the
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        <command>system-config-language</command> command.
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    </para>
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    <para>
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        The <command>centos-art.sh</command> script uses the
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        <envar>LANG</envar> environment variable to determine what
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        language to use for printing output messages from the script
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        itself, as well as the portable objects locations that need to
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        be updated or edited when you localize directory structures
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        inside the working copy of &TCAR;.
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    </para>
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    </listitem>
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    </varlistentry>
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    <varlistentry>
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    <term>Default time zone representation</term>
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    <listitem>
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    <para>
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        The time zone representation is a time correction applied to
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        the system time (stored in the BIOS clock) based on your
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        country location.  This correction is specially useful to
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        distributed computers around the world that work together and
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        need to be syncronized in time to know when things happened.
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    </para>
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    <para>
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        &TCAR; is made of one server and several workstations spread
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        around the world. In order for all these workstations to know
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        when changes in the server took place, it is required that
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        they all set their system clocks to use the same time
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        information (e.g., through UTC (Coordinated Universal Time))
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        and set the time correction for their specific countries in
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        the operating system.  Otherwise, it would be difficult to
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        know when something exactly happened.
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    </para>
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    <para>
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        Generally, setting the time information is a straight-forward
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        task and configuration tools provided by &TC;; do cover time
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        correction for most of the countries around the world.
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        However, if you need a time precision not provided by any of
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        the date and time configuration tools provided by &TC;; then,
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        you need to customize the <envar>TZ</envar> environment
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        variable in your personal profile to correct the time
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        information by yourself.  The format of <envar>TZ</envar>
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        environment variable is described in tzset(3)
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        manual page.  
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    </para>
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    </listitem>
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    </varlistentry>
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    </variablelist>
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    </sect2>
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    <sect2 id="repo-ws-config-sudo">
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    <title>Administrative Tasks</title>
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    <para>
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        Sometimes it is necessary that you perform administrative
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        tasks inside the workstation the working copy of &TCAR; is
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        stored in. These tasks might demand you to type many commands
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        (e.g., for configuring a third party repository) or just a
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        one-line command (e.g., for installing a new package).  In
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        both cases this kind of tasks require permissions that your
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        user for everyday's work must not have under no mean. 
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    </para>
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    <para>
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        To perform administrative tasks in your workstation, you need
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        to login as <emphasis>root</emphasis> or configure the
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        <command>sudo</command> program to temporarily granting the
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        permissions your regular user needs to perform the
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        administrative tasks. The configuration of
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        <command>sudo</command> program is at
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        <filename>/etc/sudoers</filename> file and you need to add the
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        <emphasis>centos</emphasis> user to the list of privileged
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        user as described in the section below:
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    </para>
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<screen>
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## Next comes the main part: which users can run what software on 
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## which machines (the sudoers file can be shared between multiple
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## systems).
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## Syntax:
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##
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##      user    MACHINE=COMMANDS
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##
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## The COMMANDS section may have other options added to it.
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##
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## Allow root to run any commands anywhere 
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root    ALL=(ALL)       ALL
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centos  ALL=(ALL)       ALL
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</screen>
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    <para>
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        This configuration is required in order for automation scripts
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        to realize administrative tasks that otherwise you would need
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        to type one by one.  It is worth to mention that all these
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        tasks are organized in the <function>prepare</function>
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        functionality of the <command>centos-art.sh</command> script
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        in the sake of reducing work and standardize the procedure of
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        performing them. It is also worth to mention that, the
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        <command>centos-art.sh</command> script is available for you
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        to run, study, improve and share your changes as described in
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        <xref linkend="licenses-gpl" />.
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    </para>
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    </sect2>
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    <sect2 id="repo-ws-config-wc">
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    <title>Working Copy</title>
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    <para>
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        Once you've installed and configured the workstation, it is
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        ready to receive the working copy of &TCAR;. In this step, you
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        use Subversion's client to communicate the source repository
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        of &TCAR;  and download all the files that make a working copy
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        of it.
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    </para>
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    <para>
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        To download the working copy of &TCAR; you need to login as
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        your everyday's work user (i.e., the
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        <emphasis>centos</emphasis> user) and use the Subversion
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        client installed in your workstation to bring all the files
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        you need to work with from the source repository down to your
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        workstation, just as the following command describes:
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    </para>
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    <screen>svn co https://projects.centos.org/svn/artwork ~/</screen>
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    <para>
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        This command will create your working copy of &TCAR; in your
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        workstation, specifically in the 
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        class="directory">/home/centos/artwork</filename> directory.
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    </para>
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    <note>
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    <para>
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        If the Subversion's client wasn't installed by default, you
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        need to install it using the following command:
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    </para>
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    <screen>sudo yum install subversion</screen>
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    </note>
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    <para>
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        Once your working copy of &TCAR; has been downloaded, you
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        should notice that there is no image files, nor documentation,
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        or localized content inside it. This is because all the files
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        provided in the working copy are source files (e.g., the files
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        needed to produce other files) and it is up to you the action
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        of render them to produce the final files (e.g., images and
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        documentation) used to implement &TCPCVI;. 
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    </para>
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    <para>
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        Another consideration to be aware of at this point, is the
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        need of verifying the software installed in the workstation,
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        as well as the creation of symbolic links to connect the
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        content produced inside the working copy to applications
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        outside it (e.g., to make available patterns, brushes, and
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        palettes produced inside the working copy in GIMP, the
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        application used to manipulate images).
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    </para>
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    <para>
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        This final preparation stuff is automated by the
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        <function>prepare</function> functionality of the
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        <command>centos-art.sh</command> script, as described in 
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        linkend="scripts-bash-prepare" />. Execute it right now,
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        to be sure your workstation and your working copy are both
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        ready to be used.
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    </para>
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    </sect2>
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</sect1>