[
    {
        "rulename": "Set severity from extra.severity",
        "if": {
            "extra.severity": ".*",
            "severity": ""
        },
        "then": {
            "severity": "{msg[extra.severity]}"
        }
    },
    {
        "rulename": "Set default severity",
        "if": {
            "extra.severity": "",
            "severity": ""
        },
        "then": {
            "severity": "undefined"
        }
    }
]