Add access log

[NotBad4U]

Overview

Access logs stores information about events that occurred on the DNS server. For instance, when someone does a DNS query, a log is recorded and stored to provide the steam-dns server administrator with information such as the IP address of the client, what qname, qtype they are requesting, result, time to answer, etc.

Solution

Where access log will be stored

For now, the access log will be printed on stdout. An administrator can let systemd to collect them and let it do the retention.

Log format

The access log can have this format: (it's a proposition)

[ The IP address of the client] [qname] [qtype] [timestamp] [time to answer]