vyos.util: add common helper to load kernel modules

l2tpv3, wireguard, wirelessmodem, nat all require additional Kernel modules
to be present on the system. Each and every interface implemented their own
way of loading a module - by copying code.

Use a generic function, vyos.util.check_kmod() to load any arbitrary kernel
module passed as string or list.

1 files changed, 9 insertions, 0 deletions

diff --git a/python/vyos/util.py b/python/vyos/util.py
index 924df6b3a..7234be6cb 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -652,3 +652,12 @@ def get_bridge_member_config(conf, br, intf):
 
     conf.set_level(old_level)
     return memberconf
+
+def check_kmod(k_mod):
+    """ Common utility function to load required kernel modules on demand """
+    if isinstance(k_mod, str):
+        k_mod = k_mod.split()
+    for module in k_mod:
+        if not os.path.exists(f'/sys/module/{module}'):
+            if call(f'modprobe {module}') != 0:
+                raise ConfigError(f'Loading Kernel module {module} failed')