fendrax

For some reason, I am only seeing this comment thread now, so sorry for the late response.

Thanks for those valuable details. But I am still a bit confused. I understand why you are saying that pi hole should be the only DNS server handling requests sent by LAN devices (including the machine hosting the DNS). That's because it is the only one which can resolve local names (well, that's actually its upstream dnsmasq running as a sibling container that does that but that's a minor detail).

But then you say there should be another DNS server to solve my problem. If I put two server entries in /etc/resolv.conf, one being pi hole and the other my ISP's DNS, the two of them will be randomly picked by DNS clients. When the ISP's is used, it will fail to translate local names. I guess there is a way to let the client try the other server after a failure but it will add some undesirable latency.

Sorry if I misunderstood your point but after reading the first comments I was quite convinced by the idea of adding a second nameserver entry in /etc/resolv.conf. Your explanations convinced me otherwise and now I have the impression that I can't really solve my initial problem in a reliable way.

Well, I have not really thought about why. I guess that's partly due to old habits of running services on the host with systemd (my migration to docker is recent and still a work in progress). But I guess I'd like to continue to be able to resolve names of local devices on my network when connected through ssh on the host. Is that inherently wrong, still? I will implement the secondary DNS as a fallback. I am hoping to get rid of the issue that way.

Yes, others have suggested something similar. I'll do that first because it is easy. Monitoring-wise, I should already be covered but since prometheus is running on the same server, it was down during the outage. There is room for improvement, for sure! I have a couple of RPis on my network that I can leverage for better monitoring.

Your suggestion looks similar to this other comment and makes sense. I'll try that!

I have never managed to wrap my head around DoH and DoT but this is on my todo list ^^

I didn't know dnsmasq has an adblock plugin, I'll have a look. Originally, I was using dnsmasq alone (running on bare metal). Then I migrated to docker and added pi-hole for ad blocking. I tried to get rid of dnsmasq but pi-hole's embedded DHCP is not as configurable as dnsmasq's and I could not address my use case.

Thanks a lot for your time!

I see. I kind of thought about it earlier today while mulling over the problem. I can definitely do that first because it's easy and makes total sense.

I already have prometheus monitoring the DNS resolution, I think. I'll check!

Thanks for taking the time to answer!

Yeah, that was my plan B. To be honest, I was not super confident that it would work when I put this setup together, because of the "host uses a container as DNS and docker uses the host as DNS" kind of circular dependency.

But people do use docker for DNS servers so it has to work, right? That's where I'd like to understand where I'm wrong. I'm fine with running pi hole and dnsmasq on the host as long as I get why this is not doable in docker.

Thanks for your input, though. That's helpful.

In both the pi-hole (exposed on the host) and dnsmasq (used as upstream by pi-hole) containers:

# Generated by Docker Engine.
# This file can be edited; Docker Engine will not make
 further changes once it
# has been modified.

nameserver 127.0.0.11
options ndots:0

# Based on host file: '/etc/resolv.conf' (internal res
olver)
# ExtServers: [host(127.0.0.1)]
# Overrides: []
# Option ndots from: internal

So they are pointing to docker's embedded DNS, itself forwarding to the host.

Contre la fédé avec des géants du domaine. Cet article de la quadrature du net sur le sujet est intéressant. Il évoque le précédent de XMPP et GTalk avant que Google transforme GTalk en Hangout et le sorte de XMPP. Le risque que Méta bouffe le fedivers après avoir capté son public est réel.

Je ne connaissais pas Rethink, merci ! En plus elle est sur FDroid, trop bien. Ca ressemble à AdAway en effet. Y avait Blokada dans le temps, aussi.

Euh ben en tout mon téléphone n'est pas rooté donc je ne crois pas. Je suis sur Lineage avec mindthegapps. Au pire ça s'essaye et tu sauras vite.

En alternative, il y a AdAway, appli libre dispo sur FDroid qui ne nécessite pas d'accorder sa confiance à un service tiers fermé. Je l'utilise depuis des années et ça marche bien. Mon pi hole ne voit plus grand chose à bloquer depuis mes appareils Android.

C'est aussi ce que je pense. Hélas les commentaires mis en avant en bas de l'article me font douter. J'espère que c'est juste une sélection biaisée.