sriov_apply: execute apply --sriov-only before network-pre.target

When activating VF LAG and at the same time changing the e-switch mode
to switchdev, the e-switch change MUST be performed before the bonding.
Trying to change it after the bond is created will fail and the driver
will report that the e-switch is busy.

In fact, all the SR-IOV initial setup must happen before the networking
configuration.

Change the order in which we call netplan apply --sriov-only to happen
before network-pre.target.

src/sriov.c

@@ -79,7 +79,7 @@ write_sriov_apply_systemd_unit(GHashTable* pfs, const char* rootdir, GError** er
 
     GString* s = g_string_new("[Unit]\n");
     g_string_append(s, "Description=Apply SR-IOV configuration\n");
-    g_string_append_printf(s, "After=network.target\n");
+    g_string_append_printf(s, "Before=network-pre.target\n");
 
     g_hash_table_iter_init(&iter, pfs);
     while (g_hash_table_iter_next (&iter, &key, NULL)) {

tests/test_sriov.py

@@ -1120,7 +1120,7 @@ def test_eswitch_mode(self):
 ExecStart=/usr/sbin/netplan rebind --debug enblue engreen
 ''', 'apply.service': '''[Unit]
 Description=Apply SR-IOV configuration
-After=network.target
+Before=network-pre.target
 After=sys-subsystem-net-devices-enblue.device
 After=sys-subsystem-net-devices-engreen.device
 
@@ -1166,7 +1166,7 @@ def test_rebind_service_generation(self):
 ExecStart=/usr/sbin/netplan rebind --debug enblue engreen
 ''', 'apply.service': '''[Unit]
 Description=Apply SR-IOV configuration
-After=network.target
+Before=network-pre.target
 After=sys-subsystem-net-devices-enblue.device
 After=sys-subsystem-net-devices-engreen.device
 
@@ -1186,7 +1186,7 @@ def test_rebind_not_delayed(self):
       link: engreen''')
         self.assert_sriov({'apply.service': '''[Unit]
 Description=Apply SR-IOV configuration
-After=network.target
+Before=network-pre.target
 After=sys-subsystem-net-devices-engreen.device
 
 [Service]
@@ -1206,7 +1206,7 @@ def test_rebind_no_iface(self):
       link: engreen''')
         self.assert_sriov({'apply.service': '''[Unit]
 Description=Apply SR-IOV configuration
-After=network.target
+Before=network-pre.target
 
 [Service]
 Type=oneshot