kea/1.4.0/kea-ik/conf/kea-dhcp4.conf

{
            "Dhcp4": {
                "control-socket": {
                    "socket-name": "\/tmp\/kea-dhcp4-ctrl.sock",
                    "socket-type": "unix"
                },
                "subnet4": [
                ],
                "hooks-libraries": [
                ],
                "interfaces-config": {
                    "interfaces": [
                        "*"
                    ]
                }
            },
            "Logging": {
                "loggers": [
                    {
                        "debuglevel": 99,
                        "name": "kea-dhcp4",
                        "output_options": [
                            {
                                "flush": true,
                                "maxsize": 10240000,
                                "maxver": 1,
                                "output": "stdout"
                            }
                        ],
                        "severity": "DEBUG"
                    }
                ]
            }
}