There is a opensource application that solves this issue, it’s called DNS Proxy Server, here some examples from official repository
It’s a DNS server that solves containers hostnames, if could not found a hostname that matches then solve it from internet as well
Start DNS Server
$ docker run --hostname dns.mageddo --restart=unless-stopped -p 5380:5380 \
-v /var/run/docker.sock:/var/run/docker.sock \
-v /etc/resolv.conf:/etc/resolv.conf \
defreitas/dns-proxy-server
It will be set automatically as your default DNS (and recover to the original when it stops)
Creating some containers for test
checking docker-compose file
$ cat docker-compose.yml
version: '3'
services:
nginx-1:
image: nginx
hostname: nginx-1.docker
network_mode: bridge
linux-1:
image: alpine
hostname: linux-1.docker
command: sh -c 'apk add --update bind-tools && tail -f /dev/null'
network_mode: bridge # that way he can solve others containers names even inside, solve nginx-2, for example
starting containers
$ docker-compose up
Solving containers
from host
nslookup nginx-1.docker
Server: 13.0.0.5
Address: 13.0.0.5#53
Non-authoritative answer:
Name: nginx-1.docker
Address: 13.0.0.6
from another container
$ docker-compose exec linux-1 ping nginx-1.docker
PING nginx-1.docker (13.0.0.6): 56 data bytes
64 bytes from 13.0.0.6: seq=0 ttl=64 time=0.034 ms
As well it solves internet hostnames
$ nslookup google.com
Server: 13.0.0.5
Address: 13.0.0.5#53
Non-authoritative answer:
Name: google.com
Address: 216.58.202.78