Commit 7f6ea2a1 authored by Kierán Meinhardt's avatar Kierán Meinhardt
Browse files

nixos/test-driver: make /etc/hosts resolution VLAN-aware 

Filter /etc/hosts entries by shared VLANs to ensure nodes resolve to
reachable interface addresses.
parent d1386a42

nixos/lib/testing/network.nix

+33 −20
Original line number Diff line number Diff line
@@ -64,29 +64,42 @@ let 
          optionalString (ipInterfaces != [ ])

            (head (head ipInterfaces).value.ipv6.addresses).address;



        # Put the IP addresses of all VMs in this machine's

        # /etc/hosts file.  If a machine has multiple

        # interfaces, use the IP address corresponding to

        # the first interface (i.e. the first network in its

        # virtualisation.vlans option).

        networking.extraHosts = concatMapAttrsStringSep "" (

          m': config:

        # Generate /etc/hosts by only including IP addresses from VLANs that

        # both the local machine and the remote machine share. This prevents

        # machines from trying to connect via unreachable interfaces (e.g.,

        # a Management VLAN) and ensures name resolution matches the

        # actual network topology of the test.

        networking.extraHosts =

          let

            localVlans = config.virtualisation.vlans;

          in

          concatMapAttrsStringSep "" (

            mName: remoteConfig:

            let

              remoteInterfaces = remoteConfig.networking.interfaces;

              sharedIps = lib.flatten (

                lib.mapAttrsToList (

                  ifaceName: ifaceCfg:

                  let

                    remoteIfaceMeta = remoteConfig.virtualisation.allInterfaces."${ifaceName}" or { };

                    vlanId = remoteIfaceMeta.vlan or null;

                  in

                  if vlanId != null && builtins.elem vlanId localVlans then

                    builtins.map (addr: addr.address) ifaceCfg.ipv4.addresses

                    ++ builtins.map (addr: addr.address) ifaceCfg.ipv6.addresses

                  else

                    [ ]

                ) remoteInterfaces

              );

              hostnames =

                optionalString (

                config.networking.domain != null

              ) "${config.networking.hostName}.${config.networking.domain} "

              + "${config.networking.hostName}\n";

                  remoteConfig.networking.domain != null

                ) "${remoteConfig.networking.hostName}.${remoteConfig.networking.domain} "

                + "${remoteConfig.networking.hostName}\n";

            in

          optionalString (

            config.networking.primaryIPAddress != ""

          ) "${config.networking.primaryIPAddress} ${hostnames}"

          + optionalString (

            config.networking.primaryIPv6Address != ""

          ) "${config.networking.primaryIPv6Address} ${hostnames}"

            builtins.concatStringsSep "" (map (ip: "${ip} ${hostnames}") sharedIps)

          ) testModuleArgs.config.allMachines;

      };



    in

    {

      key = "network-interfaces";

nixos/tests/nixos-test-driver/containers.nix

+1 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ 
    c12.succeed("ping -c 1 c1")



    # Confirm containers in vlan 2 can talk to each other.

    # <<< c2.succeed("ping -c 1 c12")  # <<< TODO: this doesn't work because c12's "primary ip" is for vlan 1

    c2.succeed("ping -c 1 c12")

    c12.succeed("ping -c 1 c2")



    # Confirm containers in separate vlans cannot talk to each other.