config: Ignore unknown options starting with ngs_

Currently, all unknown configuration options are passed to Netmiko.  This
allows to pass Netmiko-specific options easily from the NGS configuration.
However, if Netmiko does not recognize an option, it crashes with an error
such as: `__init__() got an unexpected keyword argument 'ngs_foo'`

We now ignore any option that starts with `ngs_` to help with
compatibility (old NGS with new config) and we print a warning instead of
crashing.

To give more context in this warning, we now pass the device name (as
specified in the configuration) to the device class itself.

Change-Id: Ife4e15d2c0462337b0a88a83a3ea0aef6fb78a41

Author: jonglezb

CONTRIBUTING.rst

@@ -50,10 +50,13 @@ Creating new device plugins
    ``networking_generic_switch.devices.GenericSwitch``
    and implement all the abstract methods it defines.
 
-   * Your class must accept a single argument for instantiation -
-      a dictionary with all fields given in the device config section
-      of the ML2 plugin config.
-      This will be available as ``self.config`` in the instantiated object.
+   * Your class must accept as first argument a dictionary that contains
+     all fields given in the device config section of the ML2 plugin config.
+     This will be available as ``self.config`` in the instantiated object.
+     The second argument is the device name as specified in the configuration.
+     It is recommended to accept and pass ``*args`` and ``**kwargs`` to the
+     __init__ method of the parent class: this helps to stay compatible with
+     future changes of the base class.
 
 #. Register your class under ``generic_switch.devices`` entrypoint.
 #. Add your device config to the plugin configuration file

networking_generic_switch/devices/__init__.py

@@ -47,14 +47,14 @@
 ]
 
 
-def device_manager(device_cfg):
+def device_manager(device_cfg, device_name=""):
     device_type = device_cfg.get('device_type', '')
     try:
         mgr = stevedore.driver.DriverManager(
             namespace=GENERIC_SWITCH_NAMESPACE,
             name=device_type,
             invoke_on_load=True,
-            invoke_args=(device_cfg,),
+            invoke_args=(device_cfg, device_name),
             on_load_failure_callback=_load_failure_hook
         )
     except stevedore.exception.NoUniqueMatch as exc:
@@ -75,16 +75,25 @@ def _load_failure_hook(manager, entrypoint, exception):
 
 class GenericSwitchDevice(object, metaclass=abc.ABCMeta):
 
-    def __init__(self, device_cfg):
+    def __init__(self, device_cfg, device_name=""):
         self.ngs_config = {}
         self.config = {}
+        self.device_name = device_name
         # Do not expose NGS internal options to device config.
         for opt in NGS_INTERNAL_OPTS:
             opt_name = opt['name']
             if opt_name in device_cfg.keys():
                 self.ngs_config[opt_name] = device_cfg.pop(opt_name)
             elif 'default' in opt:
                 self.ngs_config[opt_name] = opt['default']
+        # Ignore any other option starting with 'ngs_' (to avoid passing
+        # these options to Netmiko)
+        for opt_name in [o for o in device_cfg.keys() if o.startswith("ngs_")]:
+            LOG.warning("Ignoring unknown option '%(opt_name)s' for "
+                        "device %(device)s",
+                        {'opt_name': opt_name, 'device': self.device_name})
+            device_cfg.pop(opt_name)
+
         self.config = device_cfg
 
         self._validate_network_name_format()

networking_generic_switch/devices/netmiko_devices/__init__.py

@@ -96,8 +96,8 @@ class NetmikoSwitch(devices.GenericSwitchDevice):
     device output that indicate a failure to apply configuration.
     """
 
-    def __init__(self, device_cfg):
-        super(NetmikoSwitch, self).__init__(device_cfg)
+    def __init__(self, device_cfg, *args, **kwargs):
+        super(NetmikoSwitch, self).__init__(device_cfg, *args, **kwargs)
         if self.NETMIKO_DEVICE_TYPE:
             device_type = self.NETMIKO_DEVICE_TYPE
         else:

networking_generic_switch/devices/netmiko_devices/dell.py

@@ -127,8 +127,8 @@ def _switch_to_general_mode(self):
         self.PLUG_PORT_TO_NETWORK = self.PLUG_PORT_TO_NETWORK_GENERAL
         self.DELETE_PORT = self.DELETE_PORT_GENERAL
 
-    def __init__(self, device_cfg):
-        super(DellPowerConnect, self).__init__(device_cfg)
+    def __init__(self, device_cfg, *args, **kwargs):
+        super(DellPowerConnect, self).__init__(device_cfg, *args, **kwargs)
         port_mode = self.ngs_config['ngs_switchport_mode']
         switchport_mode = {
             'general': self._switch_to_general_mode,

networking_generic_switch/devices/netmiko_devices/juniper.py

@@ -72,16 +72,17 @@ class Juniper(netmiko_devices.NetmikoSwitch):
         'vlan members {segmentation_id}',
     )
 
-    def __init__(self, device_cfg):
-        super(Juniper, self).__init__(device_cfg)
-
+    def __init__(self, device_cfg, *args, **kwargs):
         # Do not expose Juniper internal options to device config.
+        juniper_cfg = {}
         for opt in JUNIPER_INTERNAL_OPTS:
             opt_name = opt['name']
-            if opt_name in self.config:
-                self.ngs_config[opt_name] = self.config.pop(opt_name)
+            if opt_name in device_cfg:
+                juniper_cfg[opt_name] = device_cfg.pop(opt_name)
             elif 'default' in opt:
-                self.ngs_config[opt_name] = opt['default']
+                juniper_cfg[opt_name] = opt['default']
+        super(Juniper, self).__init__(device_cfg, *args, **kwargs)
+        self.ngs_config.update(juniper_cfg)
 
     def send_config_set(self, net_connect, cmd_set):
         """Send a set of configuration lines to the device.

networking_generic_switch/generic_switch_mech.py

@@ -45,7 +45,7 @@ def initialize(self):
         gsw_devices = gsw_conf.get_devices()
         self.switches = {}
         for switch_info, device_cfg in gsw_devices.items():
-            switch = devices.device_manager(device_cfg)
+            switch = devices.device_manager(device_cfg, switch_info)
             self.switches[switch_info] = switch
 
         LOG.info('Devices %s have been loaded', self.switches.keys())

releasenotes/notes/log-unknown-ngs-options-8a385406055ccc98.yaml

@@ -0,0 +1,12 @@
+---
+upgrade:
+  - |
+    To improve logging, the device name is now passed to the device driver
+    class.  If you implemented an out-of-tree device driver inheriting from
+    ``GenericSwitchDevice`` or ``NetmikoSwitch``, your code needs to be adapted
+    to accept this new argument to the ``__init__`` method.  It is recommended
+    to use the ``*args, **kwargs`` pattern to accept and pass all unhandled
+    arguments to the base class.
+fixes:
+  - |
+    Ignore unknown options starting with ``ngs_`` instead of crashing.