TL;DR: This article is so far about how to disable iptables integration and choose different addressing for the ‘bridge’ (default) network.

docker default network (‘bridge’)

There are two defaults I don’t like:

  1. Default network has 172.17.0.0/16 address space
  2. Docker is altering the iptables configuration automagically

The solution is custom /etc/docker/daemon.json file:

{
  "bip": "100.64.236.1/24",
  "iptables": false
}

docker-compose

By default docker-compose creates dedicated network for each project. Addressing of those dedicated networks is again under 172.17.0.0/16 prefix.

New solution

As mentioned on docker/compose#4336 we can instruct Docker which prefix should those additional networks use:

# cat ~/.docker/daemon.json
{
  "debug" : true,
  "default-address-pools" : [
    {
      "base" : "100.64.0.0/16",
      "size" : 24
    }
  ]
}

Previous solution

This problem is fixable by forsing each service in our project to joing the default network:

version: "3.1"

services:
  app:
    image: registry.opensuse.org/opensuse/leap:15.4
    network_mode: bridge
linux