nixpkgs/nixos/tests/containers-hosts.nix

import ./make-test-python.nix (
  { pkgs, lib, ... }:
  {
    name = "containers-hosts";
    meta = {
      maintainers = with lib.maintainers; [ montag451 ];
    };

    nodes.machine =
      { lib, ... }:
      {
        virtualisation.vlans = [ ];

        networking.bridges.br0.interfaces = [ ];
        networking.interfaces.br0.ipv4.addresses = [
          {
            address = "10.11.0.254";
            prefixLength = 24;
          }
        ];

        # Force /etc/hosts to be the only source for host name resolution
        environment.etc."nsswitch.conf".text = lib.mkForce ''
          hosts: files
        '';

        containers.simple = {
          autoStart = true;
          privateNetwork = true;
          localAddress = "10.10.0.1";
          hostAddress = "10.10.0.254";

          config = { };
        };

        containers.netmask = {
          autoStart = true;
          privateNetwork = true;
          hostBridge = "br0";
          localAddress = "10.11.0.1/24";

          config = { };
        };
      };

    testScript = ''
      start_all()
      machine.wait_for_unit("default.target")

      with subtest("Ping the containers using the entries added in /etc/hosts"):
          for host in "simple.containers", "netmask.containers":
              machine.succeed(f"ping -n -c 1 {host}")
    '';
  }
)