Procedure 5.12. Building Images using Oz

1. Use the yum command to install the oz and libguestfs-tools packages.

   # yum install -y oz libguestfs-tools

2. Download the Red Hat Enterprise Linux 6 Server installation DVD ISO file.
   Although Oz supports the use of network-based installation media, in this procedure a Red Hat Enterprise Linux 6 DVD ISO will be used.
3. Use a text editor to create a TDL file for use with Oz. The following example displays the syntax for a basic TDL file.
   ⁠

   Example 5.1. TDL File

   The template below can be used to create a Red Hat Enterprise Linux 6 disk image. In particular, note the use of the rootpw element to set the password for the root user and the iso element to set the path to the DVD ISO.

   <template>
    <name>rhel65_x86_64</name>
    <description>Red Hat 6.5 x86_64 template</description>
    <os>
     <name>RHEL-6</name>
     <version>4</version>
     <arch>x86_64</arch>
     <rootpw>PASSWORD</rootpw>
     <install type='iso'>
       <iso>file:///home/user/rhel-server-6.5-x86_64-dvd.iso</iso>
     </install>
    </os>
    <commands>
      <command name='console'>
   sed -i 's/ rhgb//g' /boot/grub/grub.conf
   sed -i 's/ quiet//g' /boot/grub/grub.conf
   sed -i 's/ console=tty0 / console=ttyS0,115200n8 console=tty0 /g' /boot/grub/grub.conf
      </command>
    </commands>
   </template>

4. Run the oz-install command to build an image:

   # oz-install -u -d3 TDL_FILE

   Syntax:

   • -u ensures any required customization changes to the image are applied after guest operating installation.
   • -d3 enables the display of errors, warnings, and informational messages.
   • TDL_FILE provides the path to your TDL file.
   By default, Oz stores the resultant image in the /var/lib/libvirt/images/ directory. This location is configurable by editing the /etc/oz/oz.cfg configuration file.
5. Run the virt-sysprep command on the image to re-initialize it in preparation for upload to the Image service. Replace FILE with the path to the disk image.

   # virt-sysprep --add FILE

   Refer to the virt-sysprep manual page by running the man virt-sysprep command for information on enabling and disabling specific operations.

1. Set the environment variables used for authenticating with the Identity service by loading them from the keystonerc file associated with your user (an administrative account is not required):

   # source ~/keystonerc_userName

2. Use the glance image-create command to import your disk image:

   # glance image-create --name "NAME" \
           --is-public IS_PUBLIC \
           --disk-format DISK_FORMAT \
           --container-format CONTAINER_FORMAT \
           --file IMAGE

   Where:
   • NAME = The name by which users will refer to the disk image.
   • IS_PUBLIC = Either true or false:
     • true - All users will be able to view and use the image.
     • false - Only administrators will be able to view and use the image.
   • DISK_FORMAT = The disk image's format. Valid values include: aki, ami, ari, iso, qcow2, raw, vdi, vhd, and vmdk.
     If the format of the virtual machine disk image is unknown, use the qemu-img info command to try and identify it.
     ⁠

     Example 5.2. Using qemu-img info

     In the following example, the qemu-img info is used to determine the format of a disk image stored in the file ./RHEL65.img.

     # qemu-img info ./RHEL65.img
     image: ./RHEL65.img
     file format: qcow2
     virtual size: 5.0G (5368709120 bytes)
     disk size: 136K
     cluster_size: 65536

   • CONTAINER_FORMAT = The container format of the image. The container format is bare unless the image is packaged in a file format such as ovf or ami that includes additional metadata related to the image.
   • IMAGE = The local path to the image file (for uploading).
   For more information about the glance image-create syntax, execute:

   # glance help image-create

   Note

   If the image being uploaded is not locally accessible but is available using a remote URL, provide the URL using the --location parameter instead of using the --file parameter.

   However, unless you also specify the --copy-from argument, the Image service will not copy the image into the object store. Instead, the image will be accessed remotely each time it is required.
   ⁠

   Example 5.3. Uploading an Image to the Image service

   In this example the qcow2 format image in the file named RHEL65.img is uploaded to the Image service. It is created in the service as a publicly accessible image named RHEL 6.5.

   # glance image-create --name "RHEL 6.5" --is-public true --disk-format qcow2 \
             --container-format bare \
             --file RHEL65.img
   +------------------+--------------------------------------+
   | Property         | Value                                |
   +------------------+--------------------------------------+
   | checksum         | 2f81976cae15c16ef0010c51e3a6c163     |
   | container_format | bare                                 |
   | created_at       | 2013-01-25T14:45:48                  |
   | deleted          | False                                |
   | deleted_at       | None                                 |
   | disk_format      | qcow2                                |
   | id               | 0ce782c6-0d3e-41df-8fd5-39cd80b31cd9 |
   | is_public        | True                                 |
   | min_disk         | 0                                    |
   | min_ram          | 0                                    |
   | name             | RHEL 6.5                             |
   | owner            | b1414433c021436f97e9e1e4c214a710     |
   | protected        | False                                |
   | size             | 25165824                             |
   | status           | active                               |
   | updated_at       | 2013-01-25T14:45:50                  |
   +------------------+--------------------------------------+

3. To verify that your image was successfully uploaded, use the glance image-list command:

    # glance image-list
   +--------------+----------+-------------+------------------+----------+--------+
   | ID           | Name     | Disk Format | Container Format |Size      | Status |
   +--------------+----------+-------------+------------------+----------+--------+
   | 0ce782c6-... | RHEL 6.5 | qcow2       | bare             |213581824 | active |
   +--------------+----------+-------------+------------------+----------+--------+

   To view detailed information about an uploaded image, execute the glance image-show command using the image's identifier:

   # glance image-show 0ce782c6-0d3e-41df-8fd5-39cd80b31cd9
   +------------------+--------------------------------------+
   | Property         | Value                                |
   +------------------+--------------------------------------+
   | checksum         | 2f81976cae15c16ef0010c51e3a6c163     |
   | container_format | bare                                 |
   | created_at       | 2013-01-25T14:45:48                  |
   | deleted          | False                                |
   | disk_format      | qcow2                                |
   | id               | 0ce782c6-0d3e-41df-8fd5-39cd80b31cd9 |
   | is_public        | True                                 |
   | min_disk         | 0                                    |
   | min_ram          | 0                                    |
   | name             | RHEL 6.5                             |
   | owner            | b1414433c021436f97e9e1e4c214a710     |
   | protected        | False                                |
   | size             | 25165824                             |
   | status           | active                               |
   | updated_at       | 2013-01-25T14:45:50                  |
   +------------------+--------------------------------------+