Miek Gieben 60d5e71a1a mw/*: updates docs about upstream (#968 )

Upstream allows file structured like /etc/resolv.conf. Update docs.

Fixes #709

2017-08-22 14:56:00 +01:00

secondary

secondary enables serving a zone retrieved from a primary server.

Syntax

secondary [ZONES...]

ZONES zones it should be authoritative for. If empty, the zones from the configuration block are used. Note that without a remote address to get the zone from, the above is not that useful.

A working syntax would be:

secondary [zones...] {
    transfer from ADDRESS
    transfer to ADDRESS
    upstream ADDRESS...
}

transfer from specifies from which address to fetch the zone. It can be specified multiple times; if one does not work, another will be tried.
transfer to can be enabled to allow this secondary zone to be transferred again.
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.

secondary example.org {
    transfer from 10.0.1.1
    transfer from 10.1.2.1
}