Event Script Programming Overview

JUNOS Software event scripts automate network and router management and troubleshooting. Event scripts can perform functions available through the remote procedure calls (RPCs) supported by either of the two application programming interfaces (APIs): the JUNOS Software Extensible Markup Language (XML) API and the JUNOScript API. router output when triggered by previously configured event policy scripts. 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 router.
• Reconfigure the router to avoid or work around known problems in the JUNOS Software.
• Change the router’s configuration in response to a problem.

Event scripts are based on two application programming interfaces (APIs) to the JUNOS Software: the JUNOS XML API and the JUNOScript API, which are discussed in JUNOScript API 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 XSLT Overview. For more information about SLAX, see SLAX Overview.