[RFC] Set keep-configuration=no by default for Network Manager

netplan_cli/cli/commands/apply.py

@@ -290,11 +290,7 @@ def command_apply(self, run_generate=True, sync=False, exit_on_error=True, state
             # 2nd: start all other services
             utils.systemctl('start', netplan_wpa + netplan_ovs, sync=True)
         if restart_nm:
-            # Flush all IP addresses of NM managed interfaces, to avoid NM creating
-            # new, non netplan-* connection profiles, using the existing IPs.
             nm_interfaces = utils.nm_interfaces(restart_nm_glob, devices)
-            for iface in nm_interfaces:
-                utils.ip_addr_flush(iface)
             # clear NM state, especially the [device].managed=true config, as that might have been
             # re-set via an udev rule setting "NM_UNMANAGED=1"
             shutil.rmtree('/run/NetworkManager/devices', ignore_errors=True)

src/generate.c

@@ -304,9 +304,20 @@ int main(int argc, char** argv)
 
     /* Disable /usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf
      * (which restricts NM to wifi and wwan) if "renderer: NetworkManager" is used anywhere */
-    if (netplan_state_get_backend(np_state) == NETPLAN_BACKEND_NM || any_nm)
+    if (netplan_state_get_backend(np_state) == NETPLAN_BACKEND_NM || any_nm) {
         _netplan_g_string_free_to_file(g_string_new(NULL), rootdir, "/run/NetworkManager/conf.d/10-globally-managed-devices.conf", NULL);
 
+        /*
+         * Always try to match existing interfaces with connections.
+         * Because "netplan apply" is too aggressive with Network Manager connections it might
+         * create in-memory profiles for existing virtual interfaces.
+         * keep-configuration forces NM to use existing connection profiles for these interfaces avoiding
+         * this problem.
+         */
+        _netplan_g_string_free_to_file(g_string_new("[device]\nkeep-configuration=no\n"), rootdir,
+                                       "/run/NetworkManager/conf.d/10-keep-configuration.conf", NULL);
+    }
+
     gboolean enable_wait_online = FALSE;
     if (any_networkd)
         enable_wait_online = _netplan_networkd_write_wait_online(np_state, rootdir);

src/nm.c

@@ -1185,8 +1185,11 @@ _netplan_nm_cleanup(const char* rootdir)
                                           "/run/NetworkManager/conf.d/netplan.conf", NULL);
     g_autofree char* global_manage_path = g_strjoin(NULL, rootdir != NULL ? rootdir : "",
                                                     "/run/NetworkManager/conf.d/10-globally-managed-devices.conf", NULL);
+    g_autofree char* keep_configuration_path = g_strjoin(NULL, rootdir != NULL ? rootdir : "",
+                                                    "/run/NetworkManager/conf.d/10-keep-configuration.conf", NULL);
     unlink(confpath);
     unlink(global_manage_path);
+    unlink(keep_configuration_path);
     _netplan_unlink_glob(rootdir, "/run/NetworkManager/system-connections/netplan-*");
     return TRUE;
 }