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documentation.suse.com / Documentation de SUSE Linux Enterprise Server / AutoYaST Guide / Understanding and creating the AutoYaST control file / Creating an AutoYaST control file
Applies to SUSE Linux Enterprise Server 15 SP4

3 Creating an AutoYaST control file

3.1 Collecting information

To create the control file, you need to collect information about the systems you are going to install. This includes hardware data and network information among other things. Make sure you have the following information about the machines you want to install:

  • Hard disk types and sizes

  • Graphical interface and attached monitor, if any

  • Network interface and MAC address if known (for example, when using DHCP)

Also verify that both autoyast2-installation and autoyast2 are installed.

3.2 Using the configuration management system (CMS)

To create the control file for one or more computers, a configuration interface based on YaST is provided. This system depends on existing modules which are usually used to configure a computer in regular operation mode, for example, after SUSE Linux Enterprise Server is installed.

The configuration management system lets you easily create control files and manage a repository of configurations for use in a networked environment with multiple clients.

Configuration system
Figure 3.1: Configuration system

3.2.1 Creating a new control file

The easiest way to create an AutoYaST profile is to use an existing SUSE Linux Enterprise Server system as a template. On an already installed system, launch YaST › Miscellaneous › Autoinstallation Configuration. Then select Tools › Create Reference Profile from the menu. Choose the system components you want to include in the profile. Alternatively, create a profile containing the complete system configuration by launching YaST › Miscellaneous › Autoinstallation Cloning System or running sudo yast clone_system from the command line.

Both methods will create the file /root/autoinst.xml. The cloned profile can be used to set up an identical clone of the system it was created from. However, you will usually want to adjust the file to allow for installing multiple machines that are very similar, but not identical. This can be done by adjusting the profile with your favorite text/XML editor.

Warning
Warning: Sensitive data in profiles

Be aware that the profile might contain sensitive information such as password hashes and registration keys.

Carefully review the exported profiles and make sure to keep file permissions restrictive.

With some exceptions, almost all resources of the control file can be configured using the configuration management system. The system offers flexibility and the configuration of some resources is identical to the one available in the YaST control center. In addition to the existing and familiar modules new interfaces were created for special and complex configurations, for example for partitioning, general options and software.

Furthermore, using a CMS guarantees the validity of the resulting control file and its direct use for starting automated installation.

Make sure the configuration system is installed (package autoyast2) and call it using the YaST control center or as root with the following command (make sure the DISPLAY variable is set correctly to start the graphical user interface instead of the text-based one):

/sbin/yast2 autoyast

3.3 Creating/editing a control file manually

If editing the control file manually, make sure it has a valid syntax. To check the syntax, use the tools already available on the distribution. For example, to verify that the file is well-formed (has a valid XML structure), use the utility xmllint available with the libxml2 package:

xmllint <control file>

If the control file is not well formed, for example, if a tag is not closed, xmllint will report the errors.

To validate the control file, use the tool jing from the package with the same name. During validation, misplaced or missing tags and attributes and wrong attribute values are detected. The jing package is provided with the SUSE Software Development Kit.

jing /usr/share/YaST2/schema/autoyast/rng/profile.rng <control file>

/usr/share/YaST2/schema/autoyast/rng/profile.rng is provided by the package yast2-schema-default. This file describes the syntax and classes of an AutoYaST profile.

Note
Note: Schema extensions

AutoYaST can be extended by other products and modules, but the schema does not contain the specification for those extensions. As a consequence, when AutoYaST is given a profile that uses one of those extensions, it might report the profile as invalid.

Thus, starting in SUSE Linux Enterprise Server SP3, AutoYaST does not validate top-level unknown sections, and ignores them. For example, in the example below, <sap-inst> is not validated. The rest is validated as usual.

<general>
  <mode>
    <confirm config:type="boolean">true</confirm>
  </mode>
</general>

<sap-inst>
  <!-- this section is not validated -->>
</sap-inst>

Before going on with the autoinstallation, fix any errors resulting from such checks. The autoinstallation process cannot be started with an invalid and not well-formed control file.

You can use any XML editor available on your system or any text editor with XML support (for example, Emacs, Vim). However, it is not optimal to create the control file manually for multiple machines, and it should only be seen as an interface between the autoinstallation engine and the Configuration Management System (CMS).

Tip
Tip: Using Emacs as an XML editor

The built-in nxml-mode turns Emacs into a fully-fledged XML editor with automatic tag completion and validation. Refer to the Emacs help for instructions on how to set up nxml-mode.

3.4 Creating a control file via script with XSLT

If you have a template and want to change a few things via script or command line, use an XSLT processor like xsltproc. For example, if you have an AutoYaST control file and want to fill out the host name via script for any reason. (If doing this often, you should consider scripting it.)

First, create an XSL file:

Example 3.1: Example file for replacing the host name/domain by script
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:y2="http://www.suse.com/1.0/yast2ns"
  xmlns:config="http://www.suse.com/1.0/configns"
  xmlns="http://www.suse.com/1.0/yast2ns"
  version="1.0">
  <xsl:output method="xml" encoding="UTF-8" indent="yes" omit-xml-declaration="no" cdata-section-elements="source"/>

  <!-- the parameter names -->
  <xsl:param name="hostname"/>
  <xsl:param name="domain"/>

  <xsl:template match="/">
    <xsl:apply-templates select="@*|node()"/>
  </xsl:template>

  <xsl:template match="y2:dns">
    <xsl:copy>
      <!-- where to copy the parameters -->
      <domain><xsl:value-of select="string($domain)"/></domain>
      <hostname><xsl:value-of select="string($hostname)"/></hostname>
      <xsl:apply-templates select="@*|node()"/>
    </xsl:copy>
  </xsl:template>


  <xsl:template match="@*|node()" >
    <xsl:copy>
      <xsl:apply-templates select="@*|node()"/>
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>

This file expects the host name and the domain name as parameters from the user.

<xsl:param name="hostname"/>
<xsl:param name="domain"/>

There will be a copy of those parameters in the DNS section of the control file. This means that if there already is a domain element in the DNS section, you will get a second one, which will cause conflicts.

For more information about XSLT, go to the official Web page www.w3.org/TR/xslt

3.5 Checking a control file

Depending on the use case, creating an AutoYaST profile can be difficult, especially if you build a dynamic profile using rules/classes, ERB templates or pre-scripts. For more information, see Part III, “Managing mass installations with dynamic profiles”.

Starting with SUSE Linux Enterprise Server 15 SP3, AutoYaST validates the profile during the installation, reporting any problem found to the user. Although it is recommended to check whether the profile is correct or not, you can disable this behavior by setting the YAST_SKIP_XML_VALIDATION boot parameter to 1.

Moreover, to simplify the testing and debugging process, AutoYaST offers the check-profile command, which takes care of fetching, building and, optionally, importing the profile to detect any potential problem.

Note
Note: Results may vary

Although this command uses the same approach as the installation, the results may vary depending on the differences between the current system and installation media: YaST package versions, architecture, etc.

Warning
Warning: Use only trusted profiles

You must be careful when running this command because pre-installation scripts and ERB code would run as the root user. Use only profiles that you trust.

3.5.1 Basic checks

The simplest way to use this command is just to read and validate the profile:

> sudo  yast2 autoyast check-profile filename=autoinst.xml output=result.xml

The result.xml file contains the result of evaluating the profile. Bear in mind that, even if you do not use any advanced feature, the content of autoinst.xml and result.xml may differ. The reason is that AutoYaST does some cleaning up when it processes the profile.

check-profile can deal with remote files too:

> sudo  yast2 autoyast check-profile filename=http://192.168.1.100/autoinst.xml output=result.xml

3.5.2 Running pre-scripts

Optionally, AutoYaST can run the scripts that are included in the profile, reporting any error found during the execution. This is especially relevant if you are using a pre-installation script to modify the profile. To enable this feature, you need to set the run-scripts option to true.

> sudo  yast2 autoyast check-profile filename=http://192.168.1.100/autoinst.xml output=result.xml run-scripts=true
Warning
Warning: Scripts run as root

You must be careful when enabling the run-scripts option, because the scripts will run as root and they may affect the current system.

3.5.3 Importing the profile

It is possible to face some problems when importing a valid profile, even if it is correct. The reason is that AutoYaST does not perform any logic check when fetching, building and validating the profile.

To anticipate such problems, the check-profile command imports the profile and reports problems that it has detected. As it may take a while, you can disable this behavior by setting the import-all option to false.

> sudo  yast2 autoyast check-profile filename=http://192.168.1.100/autoinst.xml output=result.xml import-all=false

Importing the profile is a safe operation and does not alter the underlying system in any way.