nixos/networkd: make wait-online not time out

A further bug to our strange multi-user.target depending on
network-online.target issue is that systemd recently changed the
behaviour of systemd-networkd-wait-online to no longer consider the
absence of interfaces with RequiredForOnline to be sufficient to be
online: https://github.com/systemd/systemd/pull/27825

On the advice of the systemd developers
(https://github.com/systemd/systemd/issues/29388), this commit changes
the configuration of systemd-networkd-wait-online to pass --any by
default, and lets the default DHCP interfaces be RequiredForOnline
as they would be by default if the option is omitted.

It is plausible that systemd-networkd-wait-online may still fail if
there are no interfaces at all. However, that probably cannot be
avoided.

1 files changed, 4 insertions, 1 deletions

diff --git a/nixos/modules/system/boot/networkd.nix b/nixos/modules/system/boot/networkd.nix
index ef8204e2cf53..82f8714f0d75 100644
--- a/nixos/modules/system/boot/networkd.nix
+++ b/nixos/modules/system/boot/networkd.nix
@@ -2724,9 +2724,12 @@ let
         description = lib.mdDoc ''
           Whether to consider the network online when any interface is online, as opposed to all of them.
           This is useful on portable machines with a wired and a wireless interface, for example.
+
+          This is on by default if {option}`networking.useDHCP` is enabled.
         '';
         type = types.bool;
-        default = false;
+        defaultText = "config.networking.useDHCP";
+        default = config.networking.useDHCP;
       };
 
       ignoredInterfaces = mkOption {