The Sisyphean Task of DNS Client Config on Linux
Tailscale is awesome, you should use it for everything.<p>This Linux DNS stuff drives us batty at Fly.io. We run user containers as Firecracker VMs; users belong to "organizations", and organizations share a private IPv6 network. We do DNS for that private network under the fake "internal" TLD, so if you have an app "phoenix-frontend" and another app "rabbitmq-cluster", they can see each other at "phoenix-frontend.internal" and "rabbitmq-cluster.internal".<p>What you'd want in a perfect work is an option in `/etc/resolv.conf` that sends `.internal` to a special nameserver, and everything else to a normal nameserver. But as far as I can tell, there's no way to take a bare Linux VM that can accept an arbitrary container and set that capability up.<p>So instead, we end up (by default; you could override) serving _all_ customer DNS, and our `.internal` server has to forward recursive queries to things that aren't `.internal` somewhere else. This sucks; we shouldn't have to be inline for arbitrary customer DNS.<p>If there's a clean way to resolve this, so that the VM itself can just send `.internal` queries to us, and everything else to `1.1.1.1` or `8.8.8.8` or whatever the customer's container had, I would _love_ to hear it. I've come pretty close to breaking out preload in anger over this problem.