Adding Features to Client Images

Novell Linux Point of Service provides add-on features that can be added to client images generated with xscr. To add a feature to a client image, simply reference the add-on feature’s Image Specification Document (that is, child document) within the client Image Specification Document (that is, parent document). The parent document’s IncludeSpecificationList element identifies the child documents that you want ImageBuilder to include when it generates the image.

For example, to include the VNC 4 Remote Control add-on option in a client image, you must provide the URI to the vnc.xml child document in the parent document’s IncludeSpecificationList element, as follows:

<IncludeSpecificationList>
   <IncludeSpecification URI="/opt/SLES/POS/system/templates/addons/
   vnc.xml"/>
</IncludeSpecificationList>

Table 9-11 lists the Image Specification Documents for add-on features that can be added to client images.

For more information on the IncludeSpecificationList element, see IncludeSpecificationList. For a sample Image Specification Document, see Section C.3.2, Defined ImageSpecification.xml Document.

Adding Drivers

The Novell Linux Point of Service XML schema allows you to include or exclude specific drivers from a client image. To include or exclude drivers, you must reference the driver within a parent or child Image Specification Document. The DriverSpecifications element identifies the drivers that you want to include or exclude from the image.

Novell Linux Point of Service includes the driver packages listed in Table 9-12.

To include these drivers in a client image, you must list the driver name and URI in the DriverIncludeList element. Conversely, to exclude a driver, you must list the driver in the DriverExcludeList element.

For example, to include network drivers but exclude the st.ko SCSI driver from a client image, you would define the DriverSpecifications element as follows:

<DriverSpecifications>
   <DriverIncludeList>
      <DriverSet Name="netdrivers">
         <ExplicitPath URI="/kernel/drivers/net/"/>
            <DriverList>
               <Driver Name="pcnet32.ko"/>    
               <Driver Name="mii.ko"/>
               <Driver Name="natsemi.ko"/>
               <Driver Name="tulip/tulip.ko"/> 
               <Driver Name="eepro100.ko"/>       
               <Driver Name="e100.ko"/>
               <Driver Name="e1000/e1000.ko"/>
            </DriverList> 
         </DriverSet>
      </DriverIncludeList>
   <DriverExcludeList>
      <Driver Name="st.ko"/>
   </DriverExcludeList>
</DriverSpecifications>

When working with parent and child documents, remember that DriverSpecifications settings in parent documents take precedence over child documents. That means the parent document can exclude any item that is in the include list of a child document or conversely, the parent document can include any item that is in the exclude list of a child document.

For more information on the DriverSpecifications element, see DriverSpecifications. For a sample Image Specification Document with a complete driver definition, see Section C.3.2, Defined ImageSpecification.xml Document.

Adding RPMs

The Novell Linux Point of Service XML schema allows you to include or exclude RPM packages from a client image. To include or exclude an RPM package, you must reference the RPM within a parent or child Image Specification Document. The RPMSpecifications element identifies the RPMs that you want to include or exclude from the image.

For example, Novell Linux Point of Service includes an RPM package for the VT100 terminal emulator. To include the VT100 terminal emulator in a client image, you must list the name of the RPM package in the RPMIncludeList element. You must also include the URI for a DistributionSource document that defines where the VT100 RPM is located and define the ImageClass.

To exclude an RPM package from a client image, you must list the name of the RPM package in the RPMExcludeList element.

The following example includes the VT100 terminal emulator package and excludes the SCSI package from a NLD-based client image:

<RPMSpecifications>
   <RPMIncludeList>
      <RPMSet>
         <RPMList>
            <RPM Name="vt100"/>
         </RPMList>
      </RPMSet>
   </RPMIncludeList>
   <RPMExcludeList>
      <RPM Name="scsi"/>
   </RPMExcludeList>
   <DistributionSource URI="/opt/SLES/POS/system/templates
      /Distribution.xml" ImageClass="NLD"/>
</RPMSpecifications>

When working with parent and child documents, remember that RPMSpecifications settings in parent documents take precedence over child documents. That means the parent document can exclude any item that is in the include list of a child document or conversely, the parent document can include any item that is in the exclude list of a child document.

For more information on the RPMSpecifications element, see RPMSpecifications. For information on the Distribution Source Document, see Section 9.2.3, Distribution Source Document (Distribution.xml). For a sample Image Specification Document, see Section C.3.2, Defined ImageSpecification.xml Document. For a sample Distribution Source Document, see Section C.4.2, Defined Distribution.xml Document.

Managing Users and Groups within an Image

The UserGroupSpecifications element within an Image Specification Document defines the users and groups that are created within the image. All users and groups that will be logging into the Point of Service terminals configured by the current image can be pre-defined within the image.

The UserGroupSpecifications settings in the parent document take precedence over settings in child documents.

This section outlines how to manage users and groups within the UserGroupSpecifications element.

For more information on the UserGroupSpecifications element, see UserGroupSpecifications.

<UserGroupSpecifications>
   <UserList>		
      <User Name="Mandy Post"
       EncryptedPassword="d41d8cd98f00b204e9800998ecf8427e"
       HasPassword="true" UserId="mpost" HomeDirectory="/home/mpost"
       MainGroup="Admin">
      <GroupAssociation Name="All"/>
      <GroupAssociation Name="Admin"/>
      </User>
   </UserList>
</UserGroupSpecifications>

<UserGroupSpecifications>
   <GroupList>
      <Group Name="All" GroupId="001"/>
      <Group Name="Admin" GroupId="002"/>
   </GroupList>
</UserGroupSpecifications>

<UserGroupSpecifications>
   <RootSettings DisableRootAccess="true"/>
</UserGroupSpecifications>

<UserGroupSpecifications>
   <RootSettings DisableRootAccess="false"
    EncryptedRootPassword="encrypted_password"/>
</UserGroupSpecifications>

Changing the Image Language

To define the language deployed on the Point of Service terminal:

Setting Image Configuration Settings

The current Novell Linux Point of Service XML schema allows you to configure the following image settings within the ImageSpecification element in the ImageSpecification.xml document:

For an explanation of each setting, see ImageSpecification.

The following syntax in the Image Specification Document creates the Java 2.0.21 diskful image with an ext2 file system. The image time zone is Mountain Standard time, the locale is US English, and the console keymap is US.

<ImageSpecification xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="/opt/SLES/POS/ImageSpecification.xsd" SchemaVersion="1" SchemaRevision="1" ImageName="java" ImageVersion="2.0.21" Type="ext2" ImageType="diskful" Timezone="US/Mountain" Locale="en_US" Keytable="us.map.gz">

Including Fixed Configuration Files

A fixed configuration is a configuration file that provides information for a service that is hardware independent. Fixed configuration files are stored in the Image Description Tree under the files-user subdirectory.

The following instructions illustrate how to add the fixed configuration file, /etc/sysconfig/hotplug, to the Image Description Tree, /opt/SLES/POS/system/myImage-1.1.1:

The file tree within files-user is completely copied to the image when it is generated. For more information on the files-user directory, see Section 9.2.1, Image Description Tree

Using Data Images to Manage External Configuration Files

A data-only image is an ext2 image file that contains only a copy of the Image Description Tree starting at the given directory. This kind of image cannot be used as operating system or boot image. However, it can be used to add external configuration files to a Point of Service terminal.

If a disk-based system is booting and the IMAGE parameter in the config.MAC_address file includes an additional data image that will be downloaded to a /dev/ramx device, the data contents are automatically included into the system. If a data image is downloaded into a partition on the disk, the data is available at the mount point referring to the contents of the PART variable.

The advantage of using data images to add external configuration files to a Point of Service terminal is that the data image is controlled in the same way as the client image. This means you can manage, modify and refresh the configuration files independent of the client image.

The following instructions illustrate how to manage external configuration files with a data image:

With the data image listed as an IMAGE entry in the config.MAC_address file, the data image contents are copied to the Point of Service terminal after the data image has been downloaded to /dev/ram2.

To update the data image on the Point of Service terminal, do the following:

Enabling DMA on Point of Service Terminal CD Drives

Setting up a Direct Memory Access (DMA) channel for the CD drive on your Point of Service terminals speeds up the process of booting and loading an image from CD. The CDBoot image template provided with Novell Linux Point of Service includes the RPM package (hdparm) required to enable DMA so that the DMA channel is configured when the terminal boots from CD. However, if you would like DMA to be enabled beyond the initial install, you must add the DMA feature to the client image.

To add DMA functionality to a client image:

Activating and Deactivating System Services

System services are activated or deactivated in the config.system file by using the insserv command to set or remove links.

To activate a service, add the following line to the config.system file:

sbin/insserv /etc/init.d/service

To deactivate a service, add the following line to the config.system file:

sbin/insserv -r /etc/init.d/service

For more information on the config.system file, see Section 9.2.1, Image Description Tree.

Writing Post-Install Scripts

A Post-install script is always bound to a package from the setup file and is usually used to remove items from the package that are not needed for the image. This type of script must have the same name as the corresponding package and is stored in the script directory of the Image Description Tree (opt/SLES/POS/system/image_name-version/script/). The script itself is called within the image environment, which means it is not possible to damage the host system with your script even if you are using absolute paths.

A Post-install script uses the following format:

\#!/bin/sh
echo -n "Image [image_name_version]..."
test -f /.profile \&\& . /.profile

... script code

echo done

image_name-version is the name of the image to which this script belongs.

For more information on the script directory, see Section 9.2.1, Image Description Tree.