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TemplateWriting » History » Revision 16

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Justin Sherrill, 02/02/2011 11:37 AM


Templates

The following functions and macros can be used within templates. These are guaranteed to work via the safemode rendering, to ensure a template can do nothing harmful. With safemode disabled other macros may work, but are not supported at this time.

To ensure that safemode is enabled, set ":safemode_render = true" in settings.yml. Safemode rendering prevents templates from reading and writing files on the file system or modifying application data within foreman.

Accessing Templates

There are two ways to render a template, based on a single host, or based on a Hostgroup. The host or hostgroup provides all the details with which to render the template.

Host-based Rendering

Only a single template of each type may be rendered for a system. Foreman determines which template to use following these rules:

1. Only the templates of the appropriate kind and associated with the hosts operating system are considered
2. If a template has a hostgroup/environment combination that matches that of the host, use this template else
3. If a template is associated with the environment of the host, use this template, else
4. Use the first template found associated with the operating system associated with the host.

So essentially, the hostgroup/environment combination is used first, then just the environment, and finally just the operating system of the host.

To access a template of a certain type simply use this url:

/unattended/KIND_NAME

For example: /unattended/provision
would render the provisioning template. The host will be based on the IP Address it is accessed from. To spoof a template simply access the url in this manner:

/unattended/provision?spoof=192.168.0.1

where 192.168.0.1 is the ip address of the system you want to spoof. This allows you to view a template for a particular system from anywhere.

Hostgroup-based rendering

Allows any template to be rendered for any Hostgroup. When rendering using a hostgroup, @host is actually the hostgroup instead of a defined host. The default values for the hostgroup are used for templated values. This means if a value is not set in the hostgroup, you may get an error when rendering the template. To access a template using a Hostgroup to render, simply use this URL:

/unattended/template/Template Name/Hostgroup Name

For example, a hostgroup of name Finance, and a template named WebServerKickstart could be rendered using the url:

/unattended/template/WebServerKickstart/Finance

PXE Menus

Pxe Menus can be deployed to smart proxies from the Config Templates list page (/config_templates). All provision templates will be added with each of their hostgroup combinations. For example if the template "WebServerKickstart" is associated to the Hostgroup1/Production, Hostgroup2/Production, and Hostgroup2/Testing combinations, the template would only be added twice. Once for WebServerKickstart-Hostgroup1 and WebServerKickstart-Hostgroup2.

Writing templates

Functions and macros:

Name Description Example
root_pass The root password configured for the system
ks_console
snippets(name) Renders the specified snippet
foreman_url(kind) Provides the full URL to a host-rendered template of the given kind foreman_url("provision") => http://HOST/unattended/provision
@host The name of the host
@host.name The name of the host
@host.diskLayout The disklayout of the host (could come from the operating system)
@host.puppetmaster The puppetmaster the host should use
@host.architecture The arch of the host (i.e. x86_64)
@host.operatingsystem The operating system name
@host.operatingsystem.media_url
@host.operatingsystem.major The major version of the OS
@host.operatingsystem.minor The minor version of the OS
@host.operatingsystem.family The OS Family (I.e. redhat, debian, etc.)
@host.url_for_boot(:kernel)
@host.url_for_boot(:initrd)

Kickstart only variables:

Name Description Example
@dynamic
@osver
@arch
@mediapath
@epel
@yumrepo
@static

Preseed attributes:

Name Description Example
@preseed_path
@preseed_server

Updated by Justin Sherrill almost 14 years ago · 110 revisions