LUARecordValidator

LUA record validator

LUA records allow PowerDNS to execute Lua scripts for dynamic DNS content generation. They are PowerDNS-specific and not standardized by IETF.

Format: Lua script that returns the appropriate DNS record value

The LUA record can be used in two ways:

1. Implicit return mode: "functioncall(parameters)"
2. Explicit return mode: ";if(condition) then return value else return othervalue end" (note the leading semicolon to indicate explicit return mode)

Common patterns:

• IP selection based on client location: "pickclosest({'192.0.2.1', '198.51.100.1'})"
• Conditional resolution: ";if(continent('EU')) then return '192.0.2.1' else return '198.51.100.1' end"
• Availability checks: "ifportup(443, {'192.0.2.1', '198.51.100.1'})"

SECURITY CONSIDERATIONS:

• LUA records must be explicitly enabled in PowerDNS configuration
• Never serve LUA records from untrusted sources
• LUA records can expose system information and potentially lead to system compromise