network-link-*.service: Set stopIfChanged = false

This reduces the time window during which IP addresses are gone during
switch-to-configuration. A complication is that with stopIfChanged =
true, preStop would try to delete the *new* IP addresses rather than
the old one (since the preStop script now runs after the switch to the
new configuration). So we now record the actually configured addresses
in /run/nixos/network/addresses/<interface>. This is more robust in
any case.

Issue https://github.com/NixOS/nixops/issues/640.

Changed files
+20 -13
nixos
+1 -1
nixos/modules/security/polkit.nix
···
systemd.packages = [ pkgs.polkit.out ];
systemd.services.polkit.restartTriggers = [ config.system.path ];
-
systemd.services.polkit.unitConfig.X-StopIfChanged = false;
+
systemd.services.polkit.stopIfChanged = false;
# The polkit daemon reads action/rule files
environment.pathsToLink = [ "/share/polkit-1" ];
+19 -12
nixos/modules/tasks/network-interfaces-scripted.nix
···
after = [ "network-pre.target" ] ++ (deviceDependency i.name);
serviceConfig.Type = "oneshot";
serviceConfig.RemainAfterExit = true;
+
# Restart rather than stop+start this unit to prevent the
+
# network from dying during switch-to-configuration.
+
stopIfChanged = false;
path = [ pkgs.iproute ];
script =
''
+
# FIXME: shouldn't this be done in network-link?
echo "bringing up interface..."
ip link set "${i.name}" up
-
restart_network_interfaces=false
+
state="/run/nixos/network/addresses/${i.name}"
+
+
mkdir -p $(dirname "$state")
+
'' + flip concatMapStrings (ips) (ip:
let
address = "${ip.address}/${toString ip.prefixLength}";
in
''
-
echo "checking ip ${address}..."
+
echo "${address}" >> $state
if out=$(ip addr add "${address}" dev "${i.name}" 2>&1); then
-
echo "added ip ${address}..."
+
echo "added ip ${address}"
elif ! echo "$out" | grep "File exists" >/dev/null 2>&1; then
echo "failed to add ${address}"
exit 1
fi
'');
-
preStop = flip concatMapStrings (ips) (ip:
-
let
-
address = "${ip.address}/${toString ip.prefixLength}";
-
in
-
''
-
echo -n "deleting ${address}..."
-
ip addr del "${address}" dev "${i.name}" >/dev/null 2>&1 || echo -n " Failed"
-
echo ""
-
'');
+
preStop = ''
+
state="/run/nixos/network/addresses/${i.name}"
+
while read address; do
+
echo -n "deleting $address..."
+
ip addr del "$address" dev "${i.name}" >/dev/null 2>&1 || echo -n " Failed"
+
echo ""
+
done < "$state"
+
rm -f "$state"
+
'';
};
createTunDevice = i: nameValuePair "${i.name}-netdev"