Our Wikimedia DNS does not currently use any systemd-level service bindings but it should so that systemd can handle the various service dependencies automatically without us having to worry/bother about them.
For a more detailed explanation and given Wikimedia DNS' anycast-based setup: bird should not advertise any Wikimedia DNS prefixes if anycast-hc is not running, anycast-hc should not be running if dnsdist isn't running, and given that dnsdist doesn't perform any recursive functions by itself, dnsdist should depend on pdns-recursor running. (dnsdist has its own cache but that's about it.)
The only such bindings we have so far are on the doh* hosts:
```
bird.service:
After=anycast-healthchecker.service
BindsTo=anycast-healthchecker.service
```
We need to expand this for all the other services too:
```
anycast-hc.service: dnsdist.service, pdns-recursor.service
```