ifnamedhcp - Server Interface Names configured via Custom DHCP Option
After several hardware generations of our servers we had enough of the ever-changing naming schemes of the network interfaces.
This had troubled us in so many different ways:
* "Does this NIC count the ports from left to right or right to left!?" during hardware install.
* Interface names need to be specified in BGP daemon config.
* Prometheus alerting rules specify the interfaces.
* ...
The solution is simple, but very effective:
1. During installation of the server OS, we are installing a small utility binary (ifnamedhcp).
2. This binary iterates over all Ethernet interfaces, does a DHCP request and waits for the response containing a custom Option that specifies the interface name to configure.
3. The name is then configured using systemd-networkd config.
