What it is

A hosts-file generator by aliases made in a UniFi controller to be run on a UDM.

But why?

To make up for the fact that UniFi USG doesn't have hostname alias/override for clients.

How it works

It polls a UniFi controller and writes client aliases and IP addresses to a file being picked up by UDM's dnsmasq. Clients with DNS-incompatible names will be skipped.

Build

Run podman build -t unifi-dns-gen .
Note: If you are not doing this on your UDM, you need qemu-user-static-aarch64 to build this image

Run

SSH into your Dream Machine
Make a folder to hold your host files: mkdir /mnt/data/hosts
Run: podman run --name unifi-dns-gen -e UNIFI_BASEURL=https://192.168.1.1 -e UNIFI_USERNAME='REDACTED' -e UNIFI_PASSWORD='REDACTED' -e HOSTS_FILE="/hosts/unifi.hosts -v "/mnt/data/hosts:/hosts" -it --rm ghcr.io/drakulix/unifi-dns-gen:latest
Add a file with hostsdir=/mnt/data/hosts as contents to /run/dnsmasq.d
Restart dnsmasq: pkill dnsmasq

Env variable	Description	Required	Default
`UNIFI_BASEURL`	Url of the Unifi Controller @ you UDM	yes
`UNIFI_USERNAME`	Username to log into your controller	yes
`UNIFI_PASSWORD`	Password to log into your controller	yes
`UNIFI_SITE`	Site to enumerate	no	default
`HOSTS_FILE`	File to write host entries into	yes
`FIXED_ONLY`	Only write out clients with fixed ip addresses	no	`False`
`INTERVAL`	Interval at which to poll controller (in seconds)	no	60

Persist

To avoid doing this again after each restart check out the awesome udm-utilities repository and setup on-boot-scripts.

You can then download and copy on_boot.d/20-dns-alias.sh into /mnt/data/on_boot.d.

Credits

To unifi-dns and UDM-DNS-Fix

Drakulix / unifi-dns-gen

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