A composite template uses a custom domain-specific language (DSL) and a template definition in the YAML format. For more information about the YAML format, see the YAML documentation. The YAML template definition file is always named “template.yaml” and located at the root level in the composite template zip archive.

Each composite template is defined with a template alias that is unique for the Command Central environment. The only valid characters in a template alias are ASCII characters, numbers, underscore (_), dot (.), and a hyphen (-).

The template declaration in the template.yaml file consists of the template alias, the DSL version, and an optional description and version fields. The description is short and usually states the purpose of the template. You can optionally specify a version parameter, based on user-defined versions of the updates to the template definition file. For example:

Note that some of the instructions and parameters included in higher DSL versions are not supported by the lower versions of the DSL.

The following topics describe the syntax and structure of a composite template definition. See also Reference Template DSL Definition.