This module provides a varnish director for dynamic creation of backends based
on calls to the system's network address resolution service which, in turn,
typically use information from the /etc/hosts file and the Domain Name Service
(DNS), but can be configured to use other sources like LDAP or more advanced
DNS resolution where getdns is available.

While standard varnish backends defined in VCL may also be defined in terms of
host names, changes of the name service information will only be picked up
with a VCL reload.

WWW: https://github.com/nigoroll/libvmod-dynamic