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Using Extension Functions in Junos OS Automation Scripts

 

Junos OS provides extension functions that can be used in commit, op, event, and SNMP scripts to more easily accomplish scripting tasks on devices running Junos OS. The following sections outline how to import and use the extension functions for different script languages:

Using Extension Functions in SLAX and XSLT Scripts

To use the extension functions in SLAX and XSLT scripts, the script must declare the appropriate namespace Uniform Resource Identifier (URI) in the style sheet declaration. Junos OS extension functions, which have functionality that is specific to devices running Junos OS, are defined in the namespace with the associated URI http://xml.juniper.net/junos/commit-scripts/1.0 . SLAX extension functions are defined in the namespace with the associated URI http://xml.libslax.org/slax .

SLAX and XSLT scripts generally map the jcs or slax prefix to its respective URI to avoid name conflicts with standard XSLT functions and user-defined templates. The scripts then qualify the extension functions with the appropriate prefix, which is expanded into its associated URI reference during processing.

For example, the following SLAX namespace statement maps the jcs prefix to the namespace URI that defines the Junos OS extension functions used in automation scripts:

The following SLAX namespace statement maps the slax prefix to the namespace URI that defines SLAX extension functions:

To call an extension function in a SLAX or XSLT script, include any required variable declarations, call the function using jcs:function-name() or slax:function-name() as appropriate, and pass along any required or optional arguments. Arguments must be passed into the function in the precise order specified by the function definition. This is different from a template, where the parameters are assigned by name and can appear in any order. The return value of an extension function must always either be assigned to a variable or designated as output.

The following example maps the jcs prefix to the namespace identified by the URI http://xml.juniper.net/junos/commit-scripts/1.0 . The script then calls the jcs:invoke() function with one argument.

XSLT Syntax

SLAX Syntax

The following example maps the slax prefix to the namespace identified by the URI http://xml.libslax.org/slax . The script then calls the slax:get-input() function with one string argument. The version statement specifies version 1.1 of the SLAX language, which is supported in Junos OS Release 12.2 and later releases.

SLAX Syntax

Using Extension Functions in Python Scripts

Python automation scripts that import the jcs module can use a Python version of supported Junos OS and SLAX extension functions. To determine which extension functions are supported in Python scripts, see Understanding Extension Functions in Junos OS Automation Scripts.

To call the equivalent extension function in a Python script, include the import jcs statement and any required variable declarations, call the function using jcs.function_name(), and pass along any required or optional arguments. Note that in Python scripts, the extension function names must use underscores instead of hyphens. For example:

Python Syntax