[WIP][backend] Added support for plugins.

netjsonconfig/backends/base/backend.py

@@ -21,6 +21,7 @@ class BaseBackend(object):
     schema = None
     FILE_SECTION_DELIMITER = '# ---------- files ---------- #'
     list_identifiers = []
+    plugins = []
 
     def __init__(self, config=None, native=None, templates=None, context=None):
         """
@@ -49,6 +50,17 @@ def __init__(self, config=None, native=None, templates=None, context=None):
             raise ValueError('Expecting either config or native argument to be '
                              'passed during the initialization of the backend')
 
+    @classmethod
+    def add_plugins(cls, plugins):
+        for plugin in plugins:
+            plugin.schema.pop('$schema', None)
+            if getattr(cls, 'schema'):
+                cls.schema['properties'][plugin.key] = plugin.schema
+                if getattr(cls, 'converters'):
+                    cls.converters.append(plugin.converter)
+                else:
+                    cls.converters = [plugin.converter]
+
     def _load(self, config):
         """
         Loads config from string or dict

tests/openwrt/test_backend.py

@@ -8,6 +8,34 @@
 from netjsonconfig import OpenWrt
 from netjsonconfig.exceptions import ValidationError
 from netjsonconfig.utils import _TabsMixin
+from netjsonconfig.backends.openwrt.converters.base import OpenWrtConverter
+
+
+class CoovaConverter(OpenWrtConverter):
+    netjson_key = 'chilli'
+    _uci_types = ['chilli']
+
+    def to_intermediate_loop(self, block, result, index=None):
+        if block:
+            block.update({
+                '.type': 'chilli',
+                '.name': 'chilli'
+            })
+        result['chilli'] = [self.sorted_dict(block)]
+        return result
+
+
+class CoovaPlugin(object):
+    key = 'chilli'
+    converter = CoovaConverter
+    schema = {
+        "$schema": "http://json-schema.org/draft-04/schema#",
+        "type": "object",
+        "properties": {
+             "disabled": {"type": "integer"},
+             "uamsecret": {"type": "string"},
+         },
+    }
 
 
 class TestBackend(unittest.TestCase, _TabsMixin):
@@ -19,6 +47,37 @@ def test_config_copy(self):
         o.validate()
         self.assertDictEqual(config, {'interfaces': []})
 
+    def test_plugin(self):
+        config = {
+            "chilli": {
+                'disabled': 1,
+                'uamsecret': 'asd123fghj'
+            },
+        }
+        OpenWrt.add_plugins([CoovaPlugin()])
+        o = OpenWrt(config)
+        self.assertEqual(self._tabs('''package chilli
+
+config chilli 'chilli'
+    option disabled '1'
+    option uamsecret 'asd123fghj'
+'''), o.render())
+
+    def test_bad_plugin_config(self):
+        config = {
+            "chilli": {
+                'disabled': 'wrong_value',
+                'uamsecret': 'asd123fghj'
+            },
+        }
+        OpenWrt.add_plugins([CoovaPlugin()])
+        o = OpenWrt(config)
+        try:
+            o.render()
+            self.fail()
+        except ValidationError as e:
+            self.assertEqual(e.message, "'wrong_value' is not of type 'integer'")
+
     def test_json_method(self):
         config = {
             "type": "DeviceConfiguration",