wildcard dns for docker-compose using dnsmasq

dnsmasq.conf

# explicitly define host-ip mappings
address=/myapp.local/172.16.1.2
# dnsmasq entries are always wildcard entries, so this maps both myapp.local and *.myapp.local

# (yes, it's fine for this to be your entire dnsmasq config. the defaults are pretty sensible)

docker-compose.yml

version: '2' # v2 required for ip_range config support. v3 won't work.

networks:
  default:
    ipam:
      config:
        - subnet:   172.16.0.0/23 # In order to specify static IPs, we must explicitly declare subnet.
          ip_range: 172.16.0.0/24 # Range for dynamic IPs. We'll make sure to assign static IPs outside this range.
          # docs: https://docs.docker.com/compose/compose-file/compose-file-v2/#ipam
          # As of this writing, `ip_range` is not supported in v3.

services:
  dnsmasq:
    image: strm/dnsmasq
    volumes:
      - ./dnsmasq.conf:/etc/dnsmasq.conf
    ports:
      - 53:53/udp
    cap_add:
      - NET_ADMIN
    # dnsmasq container config above is taken verbatim from https://hub.docker.com/r/strm/dnsmasq
    networks:
      default:
        ipv4_address: 172.16.1.1 # Static IP here makes it possible to point other containers' dns here.
        
  myapp:
    # ...
    # your app config here
    # ...
    networks:
      default:
        ipv4_address: 172.16.1.2 # Static IP here makes dnsmasq config easy to write.

  appclient:
    # ...
    # more container config
    # ...
    dns:
      - 172.16.1.1 # dnsmasq container

# `appclient` should now be able to access `myapp` as myapp.local or foo.myapp.local

@ppatidar-conga Sure. Here is what we use at my job. Everyone is able to have working wildcard DNS with this: https://gist.github.com/boomshadow/20677ef02f110e448ee058ae6149af3a