Layout of LCG2 Templates

TOC(inline)

This page contains a description of the layout of templates for LCG2 provided by QWG and how the site customization should be integrated. See page on template framework for more details on template framework structure and site customization.

Note : QWG templates require pan compiler version 5 or later.

LCG2 Template Layout

QWG templates related to LCG2 middleware are organized in several directories for easier navigation into the template hierarchy. In the future these directories should be mapped to namespaces. Currently they are all equivalent from the pan perspective : a given template can be placed into any of the directory but should not exist in more than one directory as there is no guarantee about the search order.

Directory used by QWG LCG2 templates are :

• machine-types : templates defining the whole configuration of a given LCG2 machine type (e.g. WN, CE, SE, BDII...). There is one template per machine type. They all rely on template pro_lcg2_machine_config_base to define basic configuration of any kind of LCG2 machine.
• rpmlist : templates defining RPMs that must be loaded for a given LCG2 service. These RPMs are generated from LCG2 middleware description and should not be edited manually (manual edits will be lost next time templates are generated).
• repository : there is normally one template listing all the RPM repositories associated with the current version of the middleware. Each repository is defined in a template that is site specific.
• sources : templates that define a LCG2 service configuration. These templates are maintained manually and generally need to be updated with each version of the middleware. They are centrally maintained by QWG maintainers. These templates are generic and take as input variables to define a specific site configuration. They should not (normally) be edited manually.
• vo-legacy : templates to define VOs, using scheme used by previous version of QWG templates (until 2.7.0). They are provided for backward compatibility but should not be used anymore, after migrating to the new, much more flexible, scheme.
• vo : templates to configure VOs. These templates and associated functions provide a flexible way of configuring VOs. They take as input the list of VOs to be configured, from variable VOS.

Site Customization of LCG2 Templates

Site customization to LCG templates is done through a small set of templates used to define variables used as input by QWG templates. This doesn't cover OS basic configurationt that is decribed in the page about template framework.

Site parameters

All site parameters related to LCG middleware are supposed to be declared in template pro_lcg2_config_site.tpl. A sensible default value is provided for all required variables in template source:template/trunk/grid/lcg-2.7.0/sources/pro_lcg2_config_system_defaults.tpl provided as part of QWG templates. This template must be included as part of the site pro_lcg2_config_site.tpl that must provide an explicit value for at least all the variable undef in template source:template/trunk/grid/lcg-2.7.0/sources/pro_lcg2_config_system_defaults.tpl.

Cluster parameters

For every cluster, it is possible to customize configuration in template pro_site_cluster_info.tpl. As a general rule, you need to define the following properties for each cluster (value mentionned are just examples) :

#
# basic site information
#
"/system/cluster/name" = "LCG 2.7.0";
"/system/cluster/type" = "batch";
"/system/state" = "production";
"/system/siterelease" = "SL 3.05";
"/system/rootmail" = "grid.support@lal.in2p3.fr";

You can also define variable FILESYSTEM_CONFIG_SITE as an alternative template name containing a filesystem layout for the cluster (or node if this is in a machine profile). For example :

FILESYSTEM_CONFIG_SITE = "pro_lcg2_system_filesystems";

VO Configuration

VO configuration consists to define variable VOS in pro_lcg2_config_site.tpl. This variable can also be redefined in the context of a specific node, if pro_lcg2_config_site.tpl defines VOS as a default value.

Adding a new VO to standard VOs require creating 2 templates. Use an existing VO, in vo directory, as a template.