openstack-manuals/doc/image-guide/ch_creating_images_automatically.xml

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<chapter xmlns="http://docbook.org/ns/docbook"
    xmlns:xi="http://www.w3.org/2001/XInclude"
    xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
    xml:id="ch_creating_images_automatically">
    <title>Tool support for image creation</title>
    <?dbhtml stop-chunking?>
    <para>There are several tools that are designed to automate image
        creation.</para>
    <section xml:id="oz">
        <title>Oz</title>
        <para><link
                xlink:href="https://github.com/clalancette/oz/wiki"
                >Oz</link> is a command-line tool that automates the
            process of creating a virtual machine image file. Oz is a
            Python app that interacts with KVM to step through the
            process of installing a virtual machine. It uses a
            predefined set of kickstart (Red Hat-based systems) and
            preseed files (Debian-based systems) for operating systems
            that it supports, and it can also be used to create
            Microsoft Windows images. On Fedora, install Oz with yum:<screen><prompt>#</prompt> <userinput>yum install oz</userinput></screen><note>
                <para>As of this writing, there are no Oz packages for
                    Ubuntu, so you will need to either install from
                    source or build your own .deb file.</para>
            </note></para>
        <para>A full treatment of Oz is beyond the scope of this
            document, but we will provide an example. You can find
            additional examples of Oz template files on github at
                <link
                xlink:href="https://github.com/rackerjoe/oz-image-build/tree/master/templates"
                >rackerjoe/oz-image-build/templates</link>. Here's how
            you would create a CentOS 6.4 image with Oz.</para>
        <para>Create a template file (we'll call it
                <filename>centos64.tdl</filename>) with the following
            contents. The only entry you will need to change is the
                <literal>&lt;rootpw></literal>
            contents.<programlisting language="xml">&lt;template>
  &lt;name>centos64&lt;/name>
  &lt;os>
    &lt;name>CentOS-6&lt;/name>
    &lt;version>4&lt;/version>
    &lt;arch>x86_64&lt;/arch>
    &lt;install type='iso'>
      &lt;iso>http://mirror.rackspace.com/CentOS/6/isos/x86_64/CentOS-6.4-x86_64-bin-DVD1.iso&lt;/iso>
    &lt;/install>
    &lt;rootpw>CHANGE THIS TO YOUR ROOT PASSWORD&lt;/rootpw>
  &lt;/os>
  &lt;description>CentOS 6.4 x86_64&lt;/description>
  &lt;repositories>
    &lt;repository name='epel-6'>
      &lt;url>http://download.fedoraproject.org/pub/epel/6/$basearch&lt;/url>
      &lt;signed>no&lt;/signed>
    &lt;/repository>
  &lt;/repositories>
  &lt;packages>
    &lt;package name='epel-release'/>
    &lt;package name='cloud-utils'/>
    &lt;package name='cloud-init'/>
  &lt;/packages>
  &lt;commands>
    &lt;command name='update'>
yum update
yum clean all
sed -i '/^HWADDR/d' /etc/sysconfig/network-scripts/ifcfg-eth0
echo -n > /etc/udev/rules.d/70-persistent-net.rules
echo -n > /lib/udev/rules.d/75-persistent-net-generator.rules
    &lt;/command>
  &lt;/commands>
&lt;/template></programlisting>
       </para>
        <para>This Oz template specifies where to download the Centos
            6.4 install ISO. Oz will use the version information to
            identify which kickstart file to use. In this case, it
            will be <link
                xlink:href="https://github.com/clalancette/oz/blob/master/oz/auto/RHEL6.auto"
                >RHEL6.auto</link>. It adds EPEL as a repository and
            install the <literal>epel-release</literal>,
                <literal>cloud-utils</literal>, and
                <literal>cloud-init</literal> packages, as specified
            in the <literal>packages</literal> section of the
            file.</para>
        <para>After Oz does the initial OS install using the kickstart
            file, it customizes the image by doing an update. It also
            removes any reference to the eth0 device that libvirt
            creates while Oz does the customizing, as specified
            in the <literal>command</literal> section of the XML
            file.</para>
        <para>To run this, do, as root:</para>
        <para><screen><prompt>#</prompt> <userinput>oz-install -d3 -u centos64.tdl -x centos64-libvirt.xml</userinput></screen><itemizedlist>
                <listitem>
                    <para>The <literal>-d3</literal> flag tells Oz to
                        show status information as it runs.</para>
                </listitem>
                <listitem>
                    <para>The <literal>-u</literal> tells Oz to do the
                        customization (install extra packages, run the
                        commands) once it does the initial
                        install.</para>
                </listitem>
                <listitem>
                    <para>The <literal>-x &lt;filename></literal> flag
                        tells Oz what filename to use to write out a
                        libvirt XML file (otherwise it will default to
                        something like
                            <filename>centos64Apr_03_2013-12:39:42</filename>.</para>
                </listitem>
            </itemizedlist>If you leave out the <literal>-u</literal>
            flag, or you want to edit the file to do additional
            customizations, you can use the
                <command>oz-customize</command> command, using the
            libvirt XML file that <command>oz-install</command>
            creates. For example:
            <screen><prompt>#</prompt> <userinput>oz-customize -d3 centos64.tdl centos64-libvirt.xml</userinput></screen>
            Oz will invoke libvirt to boot the image inside of KVM,
            then Oz will ssh into the instance and perform the
            customizations.</para>
    </section>
    <section xml:id="vmbuilder">
        <title>VMBuilder</title>
        <para><link xlink:href="https://launchpad.net/vmbuilder"
                >VMBuilder</link> (Virtual Machine Builder) is a
            command-line tool that creates virtual machine images for
            different hypervisors. The version of VMBuilder that ships
            with Ubuntu can only create Ubuntu virtual machine guests.
            The version of VMBuilder that ships with Debian can create
            Ubuntu and Debian virtual machine guests.</para>
        <para>The <link
                xlink:href="https://help.ubuntu.com/12.04/serverguide/jeos-and-vmbuilder.html"
                    ><citetitle>Ubuntu Server Guide</citetitle></link>
            has documentation on how to use VMBuilder to create an
            Ubuntu image.</para>
    </section>
    <section xml:id="boxgrinder">
        <title>BoxGrinder</title>
        <para>
            <link xlink:href="http://boxgrinder.org/"
                >BoxGrinder</link> is another tool for creating
            virtual machine images, which it calls appliances.
            BoxGrinder can create Fedora, Red Hat Enterprise Linux, or
            CentOS images. BoxGrinder is currently only supported on
            Fedora.</para>
    </section>
    <section xml:id="veewee">
        <title>VeeWee</title>
        <para><link xlink:href="https://github.com/jedi4ever/veewee">
                VeeWee</link> is often used to build <link
                xlink:href="http://vagrantup.com">Vagrant</link>
            boxes, but it can also be used to build KVM images.</para>
    </section>
    <section xml:id="packer">
        <title>Packer</title>
        <para><link xlink:href="http://www.packer.io/">
                Packer</link> is a tool for creating machine images for multiple platforms
                from a single source configuration.
        </para>
    </section>
    <section xml:id="imagefactory">
        <title>imagefactory</title>
        <para><link xlink:href="http://imgfac.org/"
                >imagefactory</link> is a newer tool designed to
            automate the building, converting, and uploading images to
            different cloud providers. It uses Oz as its back-end and
            includes support for OpenStack-based clouds.</para>
    </section>
    <section xml:id="susestudio">
        <title>SUSE Studio</title>
        <para><link xlink:href="http://susestudio.com">SUSE
                Studio</link> is a web application for building and
            testing software applications in a web browser. It
            supports the creation of physical, virtual or cloud-based
            applications and includes support for building images for
            OpenStack based clouds using SUSE Linux Enterprise and
            openSUSE as distributions.</para>
    </section>
</chapter>