Hi,
I'm using the official pihole docker image (in combination with cloudflared and dhcphelper).
Everything is working fine: my clients in the "normal" network are getting IPs and correct DNS settings assigned name resolving also works fine here.
The problem: in my other docker containers external (non docker) DNS resolving does not work.
I mapped the port 53 tcp+udp to the docker host machine and added "127.0.0.1" to the daemon.json.
Additionally I added the (static) ip of the docker host as dns entry in the docker-compose files of the other containers. (resolve.conf in the containers unchanged "127.0.0.11").
As I checked the pihole query log I could see the requests there. So the docker daemon did forward them correctly to pihole. And pihole shows no resolve problems (everything green). But the reply seems to never reach the docker daemon:
[resolver] read from DNS server failed, read udp 172.18.0.5:45844->192.168.31.5:53: i/o timeout"
I spend two days on searching for a solution for this problem but I'm out of ideas.
Here are my configs and outputs:
gerneral:
Network 192.168.31.0/24
docker bridge network (self created): docker_main "172.18.0.0/16" -> for all containers to get network access (automatic assigned ips)
docker bridge network (self created): "pihole_pihole" "172.20.0.0/16" -> for communication between pihole and cloudflared (manual assigned ips)
docker host:
ubuntu 20.04 on raspberry pi 4 IP: 192.168.31.5 (static) hostname: xwing
nslookup works:
ubuntu@xwing:/apps/pihole$ nslookup google.com
Server: 127.0.0.1
Address: 127.0.0.1#53
Non-authoritative answer:
Name: google.com
Address: 142.250.186.78
Name: google.com
Address: 2a00:1450:4001:800::200e
pihole:
docker compose:
version: "3.7"
services:
pihole:
container_name: pihole
image: pihole/pihole:latest
networks:
pihole:
ipv4_address: "172.20.0.200"
default: {}
ports:
- "53:53/tcp"
- "53:53/udp"
# - "192.168.31.5:53:53/udp"
- "8088:80/tcp"
expose:
- "80"
- "443"
environment:
- TZ=Europe/Berlin
- WEBPASSWORD=PW
- DNSSEC=True
- PROXY_LOCATION=pihole
- VIRTUAL_HOST=pihole.lan
- VIRTUAL_PROTO=https
- VIRTUAL_PORT=443
- VIRTUAL_PORT=80
- DNS1=172.20.0.201#5053
- DNSMASQ_LISTENING=all
# Volumes store your data between container upgrades
volumes:
- './data/etc-pihole/:/etc/pihole/'
- './data/etc-dnsmasq.d/:/etc/dnsmasq.d/'
dns:
- 127.0.0.1
- 172.20.0.201:5053
- 1.1.1.1
restart: unless-stopped
cap_add:
- NET_ADMIN
depends_on:
- cloudflared
- dhcphelper
dhcphelper:
restart: unless-stopped
container_name: dhcphelper
network_mode: "host"
image: homeall/dhcphelper:latest
environment:
IP: '172.20.0.200'
cap_add:
- NET_ADMIN
cloudflared:
image: crazymax/cloudflared:latest
container_name: cloudflared
hostname: cloudflared
networks:
pihole:
ipv4_address: "172.20.0.201"
default: {}
environment:
- TZ=Europe/Berlin
- TUNNEL_DNS_UPSTREAM=https://1.1.1.1/dns-query,https://1.0.0.1/dns-query
restart: always
networks:
default:
external:
name: docker_main
pihole:
ipam:
driver: default
config:
- subnet: 172.20.0.0/24
an other docker container (zwigbee2mqtt):
network is working and we can reach the host with 192.168.31.5 but (external) name resolution is not working (docker internal is working):
/app # ping 192.168.31.5
PING 192.168.31.5 (192.168.31.5): 56 data bytes
64 bytes from 192.168.31.5: seq=0 ttl=64 time=0.409 ms
64 bytes from 192.168.31.5: seq=1 ttl=64 time=0.465 ms
^C
--- 192.168.31.5 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.409/0.437/0.465 ms
/app # ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: seq=0 ttl=113 time=27.086 ms
64 bytes from 8.8.8.8: seq=1 ttl=113 time=27.274 ms
^C
--- 8.8.8.8 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 27.086/27.180/27.274 ms
/app # ping google.com
ping: bad address 'google.com'
/app # ping pihole
PING pihole (172.18.0.4): 56 data bytes
64 bytes from 172.18.0.4: seq=0 ttl=64 time=0.616 ms
64 bytes from 172.18.0.4: seq=1 ttl=64 time=0.536 ms
^C
--- pihole ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.536/0.576/0.616 ms
/app # cat /etc/resolv.conf
nameserver 127.0.0.11
options ndots:0
docker compose:
version: '3.7'
services:
zigbee2mqtt:
container_name: zigbee2mqtt
image: koenkk/zigbee2mqtt:latest
dns: 192.168.31.5
volumes:
- ./data:/app/data
devices:
- /dev/ttyUSB0:/dev/ttyUSB0
restart: unless-stopped
environment:
- TZ=Europe/Berlin
networks:
default:
external:
name: docker_main
