network-programmingdockerdocker-composenic

Docker - how to set iface name when creating a new network


After creating a new network with:

docker network create test-net

and running ifconfig on the host, a new interface name is being listed:

br-f2b630e4e141 Link encap:Ethernet  HWaddr 02:42:48:fe:cb:86  
          inet addr:172.18.0.1  Bcast:0.0.0.0  Mask:255.255.0.0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
  1. Is there a way to create this network and specify the iface name, for example docker1 or test-net?

  2. In case of docker-compose, can we also specify iface name inside the docker-compose.yml file?


Solution

  • 1. with docker network command

    There is a --opt option which can be used like this:

    docker network create --opt com.docker.network.bridge.name=br_test test-net

    and it seems to work:

    $ ifconfig
    br_test   Link encap:Ethernet  HWaddr 02:42:8f:3b:24:32  
              inet addr:172.18.0.1  Bcast:0.0.0.0  Mask:255.255.0.0
              UP BROADCAST MULTICAST  MTU:1500  Metric:1
              RX packets:0 errors:0 dropped:0 overruns:0 frame:0
              TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:0 
              RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
    

    found about --opt here: https://docs.docker.com/engine/userguide/networking/#the-dockergwbridge-network

    2. with docker-compose

    inside the docker-compose.yml:

    networks:
      test-net:
        driver: bridge
        ipam:
         driver: default
         config:
           - subnet: 172.100.0.0/16
        driver_opts:
          com.docker.network.bridge.name: br_test
    

    Documentation:

    As gene_wood mentions in his comment, more information can be found here 👉 docs.docker.com/engine/network/drivers/bridge/#options