Front end scripts

Front end scripts are inline in the fast path.

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Because frontend scripts are in the fast path. You need to use T.async methods to perform I/O in a separate slow path provided by the Trisul framework.

List of frontend script types

You can hook your lua scripts into the following points in the frontend.

Name	Called when	Notes
countergroup	During initialization	Create a new counter group
simplecounter	Each packet	Inspect packet contents and update meter/alerts
flowmonitor	When interesting data is seen per flow	Inspect HTTP headers, TLS certs, then attach counters to flows
fileextract	Events in HTTP layer	Flexible platform to extract files transferred via HTTP
reassembly	TCP reassembly	Control and process output from Trisul’s TCP reassembly engine