file

file enables serving zone data from an RFC 1035-style master file.

Description

The file plugin is used for an “old-style” DNS server. It serves from a preloaded file that exists on disk. If the zone file contains signatures (i.e. is signed, i.e. DNSSEC) correct DNSSEC answers are returned. Only NSEC is supported! If you use this setup you are responsible for resigning the zonefile.

Syntax

file DBFILE [ZONES...]
  • DBFILE the database file to read and parse. If the path is relative the path from the root directive will be prepended to it.
  • ZONES zones it should be authoritative for. If empty, the zones from the configuration block are used.

If you want to round robin A and AAAA responses look at the loadbalance plugin.

file DBFILE [ZONES... ] {
    transfer to ADDRESS...
    no_reload
    upstream ADDRESS...
}
  • transfer enables zone transfers. It may be specified multiples times. To or from signals the direction. ADDRESS must be denoted in CIDR notation (127.0.0.132 etc.) or just as plain addresses. The special wildcard * means: the entire internet (only valid for ‘transfer to’). When an address is specified a notify message will be send whenever the zone is reloaded.
  • no_reload by default CoreDNS will try to reload a zone every minute and reloads if the SOA’s serial has changed. This option disables that behavior.
  • upstream defines upstream resolvers to be used resolve external names found (think CNAMEs) pointing to external names. This is only really useful when CoreDNS is configured as a proxy, for normal authoritative serving you don’t need or want to use this. ADDRESS can be an IP address, and IP:port or a string pointing to a file that is structured as /etc/resolv.conf.

Examples

Load the example.org zone from example.org.signed and allow transfers to the internet, but send notifies to 10.240.1.1

example.org {
    file example.org.signed {
        transfer to *
        transfer to 10.240.1.1
    }
}

Or use a single zone file for multiple zones:

. {
    file example.org.signed example.org example.net {
        transfer to *
        transfer to 10.240.1.1
    }
}