1{ 2 # exists boolean expression 3 # empty configs are not accepted by Kea 4 "Dhcp4": { 5 "valid-lifetime": 1800, 6 "client-classes": [ 7 # use exists in a reductible match if 8 { 9 "name": "reductible", 10 /// from: match if exists dhcp.host-name 11 "test": "option[12].exists" 12 } 13 ] 14// # if test is a boolean too 15// "statement": { 16// "if": { 17// "condition": { 18// "exists": { 19// "universe": "dhcp", 20// "name": "host-name", 21// "code": 12 22// } 23// }, 24// "then": [ 25// { 26// /// Kea does not support yet log statements 27// /// Reference Kea #234 28// "log": { 29// "priority": "info", 30// "message": { 31// "concat": { 32// "left": "hostname:", 33// "right": { 34// "option": { 35// "universe": "dhcp", 36// "name": "host-name", 37// "code": 12 38// } 39// } 40// } 41// } 42// } 43// } 44// ] 45// } 46// } 47 } 48} 49