Event Script Programming Overview

Junos OS event scripts automate network and device management and troubleshooting. Event scripts can perform functions available through the remote procedure calls (RPCs) supported by either Junos XML management protocol or the Junos Extensible Markup Language (XML) API. Event scripts are executed by the event process (eventd).

Event scripts allow you to do the following things:

• Diagnose and fix network problems automatically.
• Monitor the overall status of a device.
• Reconfigure the device to avoid or work around known problems in the Junos OS.
• Change the device’s configuration in response to a problem.

Event scripts are based on the Junos XML management protocol and the Junos XML API, which are discussed in Junos XML Management Protocol and Junos XML API Overview. Event scripts can be written in either the Extensible Stylesheet Language Transformations (XSLT) or Stylesheet Language Alternative Syntax (SLAX) scripting language. Event scripts use XPath to locate the operational objects to be inspected and XSLT constructs to specify the actions to perform on the located operational objects. The actions can change the output or execute additional commands based on the output. For more information about XPath and XSLT, see XPath Overview and XSLT Overview. For more information about SLAX, see SLAX Overview.