feat: implements delete policy (#8)

* finish main part of delete policy

finish remove policy

fix problem of remove policy

* add remove_filtered_policy

* remove useless line

Author: AmosChenYQ

.travis.yml

@@ -9,7 +9,7 @@ install:
 - pip install -r requirements.txt
 - pip install coveralls
 script:
-- coverage run -m unittest discover -s tests -t tests
+- coverage run -m unittest discover --verbose --start-directory tests/ --pattern "test_*.py" --top-level-directory tests/
 after_success:
 - coveralls
 deploy:

casbin_pymongo_adapter/adapter.py

@@ -1,4 +1,3 @@
-import casbin
 from casbin import persist
 from pymongo import MongoClient
 
@@ -19,10 +18,9 @@ def __init__(self, ptype = None, v0 = None, v1 = None, v2 = None, v3 = None, v4
     def dict(self):
         d = {'ptype': self.ptype}
 
-        for i, v in enumerate([self.v0, self.v1, self.v2, self.v3, self.v4, self.v5]):
-            if v is None:
-                break
-            d['v' + str(i)] = v
+        for value in dir(self):
+            if getattr(self, value) is not None and value.startswith('v') and value[1:].isnumeric():
+                d[value] = getattr(self, value)
 
         return d
 
@@ -36,57 +34,73 @@ class Adapter(persist.Adapter):
     """the interface for Casbin adapters."""
 
     def __init__(self, uri, dbname, collection="casbin_rule"):
+        """Create an adapter for Mongodb
+
+        Args:
+            uri (str): This should be the same requiement as pymongo Client's 'uri' parameter. 
+                          See https://pymongo.readthedocs.io/en/stable/api/pymongo/mongo_client.html#pymongo.mongo_client.MongoClient.
+            dbname (str): Database to store policy.
+            collection (str, optional): Collection of the choosen database. Defaults to "casbin_rule".
+        """
         client = MongoClient(uri)
         db = client[dbname]
         self._collection = db[collection]
 
     def load_policy(self, model):
-        '''
-        implementing add Interface for casbin \n
-        load all policy rules from mongodb \n
-        '''
+        """Implementing add Interface for casbin. Load all policy rules from mongodb
+
+        Args:
+            model (CasbinRule): CasbinRule object
+        """
 
         for line in self._collection.find():
             if 'ptype' not in line:
                 continue
-
             rule = CasbinRule(line['ptype'])
-            if 'v0' in line:
-                rule.v0 = line['v0']
-            if 'v1' in line:
-                rule.v1 = line['v1']
-            if 'v2' in line:
-                rule.v2 = line['v2']
-            if 'v3' in line:
-                rule.v3 = line['v3']
-            if 'v4' in line:
-                rule.v4 = line['v4']
-            if 'v5' in line:
-                rule.v5 = line['v5']
+            for key, value in line.items():
+                setattr(rule, key, value)
 
             persist.load_policy_line(str(rule), model)
 
     def _save_policy_line(self, ptype, rule):
         line = CasbinRule(ptype=ptype)
-        if len(rule) > 0:
-            line.v0 = rule[0]
-        if len(rule) > 1:
-            line.v1 = rule[1]
-        if len(rule) > 2:
-            line.v2 = rule[2]
-        if len(rule) > 3:
-            line.v3 = rule[3]
-        if len(rule) > 4:
-            line.v4 = rule[4]
-        if len(rule) > 5:
-            line.v5 = rule[5]
+        for index, value in enumerate(rule):
+            setattr(line, f'v{index}', value)
         self._collection.insert_one(line.dict())
-
-    def save_policy(self, model):
-        '''
-        implementing add Interface for casbin \n
-        save the policy in mongodb \n
-        '''
+    
+    def _find_policy_lines(self, ptype, rule):
+        line = CasbinRule(ptype=ptype)
+        for index, value in enumerate(rule):
+            setattr(line, f'v{index}', value)
+        return self._collection.find(line.dict())
+    
+    def _delete_policy_lines(self, ptype, rule):
+        line = CasbinRule(ptype=ptype)
+        for index, value in enumerate(rule):
+            setattr(line, f'v{index}', value)
+        
+        # if rule is empty, do nothing
+        # else find all given rules and delete them
+        if len(line.dict()) == 0:
+            return 0
+        else:
+            line_dict = line.dict()
+            line_dict_keys_len = len(line_dict)
+            results = self._collection.find(line_dict)
+            to_delete = [result['_id'] for result in results 
+                            if line_dict_keys_len  == len(result.keys()) - 1]
+            results = self._collection.delete_many({'_id' : {'$in': to_delete}})
+            return results.deleted_count
+    
+    def save_policy(self, model) -> bool:
+        """Implement add Interface for casbin. Save the policy in mongodb
+
+        Args:
+            model (Class Model): Casbin Model which loads from .conf file usually. 
+
+        Returns:
+            bool: True if succeed
+        """
         for sec in ["p", "g"]:
             if sec not in model.model.keys():
                 continue
@@ -96,15 +110,51 @@ def save_policy(self, model):
         return True
 
     def add_policy(self, sec, ptype, rule):
-        """add policy rules to mongodb"""
+        """Add policy rules to mongodb
+
+        Args:
+            sec (str): Section name, 'g' or 'p'
+            ptype (str): Policy type, 'g', 'g2', 'p', etc.
+            rule (CasbinRule): Casbin rule will be added
+
+        Returns:
+            bool: True if succeed else False
+        """
         self._save_policy_line(ptype, rule)
+        return True
 
     def remove_policy(self, sec, ptype, rule):
-        """delete policy rules from mongodb"""
-        pass
+        """Remove policy rules in mongodb(rules duplicate are also removed)
+
+        Args:
+            ptype (str): Policy type, 'g', 'g2', 'p', etc.
+            rule (CasbinRule): Casbin rule if it is exactly same as will be removed.
+        
+        Returns:
+            Number: Number of policies be removed
+        """
+        deleted_count = self._delete_policy_lines(ptype, rule)
+        return deleted_count > 0
 
     def remove_filtered_policy(self, sec, ptype, field_index, *field_values):
+        """Remove policy rules taht match the filter from the storage.
+           This is part of the Auto-Save feature.
+
+        Args:
+            ptype (str): Policy type, 'g', 'g2', 'p', etc.
+            rule (CasbinRule): Casbin rule will be removed
+            field_index (int): The policy index at which the filed_values begins filtering. Its range is [0, 5]
+            field_values(List[str]): A list of rules to filter policy which starts from 
+
+        Returns:
+            bool: True if succeed else False
         """
-        delete policy rules for matching filters from mongodb
-        """
-        pass
+        if not (0 <= field_index <=5):
+            return False
+        if not (1 <= field_index + len(field_values) <= 6):
+            return False
+        query = {f'v{index + field_index}' : value 
+                        for index, value in enumerate(field_values)}
+        query['ptype'] = ptype
+        results = self._collection.delete_many(query)
+        return results.deleted_count > 0

tests/rbac_with_resources_roles.conf

@@ -0,0 +1,15 @@
+[request_definition]
+r = sub, obj, act
+
+[policy_definition]
+p = sub, obj, act
+
+[role_definition]
+g = _, _
+g2 = _, _
+
+[policy_effect]
+e = some(where (p.eft == allow))
+
+[matchers]
+m = g(r.sub, p.sub) && g2(r.obj, p.obj) && r.act == p.act