Add setters for first-level Nornir inventory attributes (#229)

* Add support for setters

* black

* Minor cleanup

nornir/core/inventory.py

@@ -201,26 +201,46 @@ def hostname(self):
         """String used to connect to the device. Either ``hostname`` or ``self.name``"""
         return self.get("hostname", self.name)
 
+    @hostname.setter
+    def hostname(self, value):
+        self.data["hostname"] = value
+
     @property
     def port(self):
         """Either ``port`` or ``None``."""
         return self.get("port")
 
+    @port.setter
+    def port(self, value):
+        self.data["port"] = value
+
     @property
     def username(self):
         """Either ``username`` or user running the script."""
         return self.get("username", getpass.getuser())
 
+    @username.setter
+    def username(self, value):
+        self.data["username"] = value
+
     @property
     def password(self):
         """Either ``password`` or empty string."""
         return self.get("password", "")
 
+    @password.setter
+    def password(self, value):
+        self.data["password"] = value
+
     @property
     def platform(self):
         """OS the device is running. Defaults to ``platform``."""
         return self.get("platform")
 
+    @platform.setter
+    def platform(self, value):
+        self.data["platform"] = value
+
     def get_connection_parameters(
         self, connection: Optional[str] = None
     ) -> Dict[str, Any]:

tests/core/test_inventory.py

@@ -249,3 +249,31 @@ def test_to_dict(self):
             },
         }
         assert inventory.filter(role="www").to_dict() == expected
+
+    def test_setters(self):
+        """Test explicit setters specified in inventory."""
+        defaults = {}
+        g1 = Group(name="g1")
+        h1 = Host(name="host1", groups=[g1], defaults=defaults)
+
+        g1.hostname = "group_hostname"
+        assert h1.hostname == "group_hostname"
+        g1.platform = "group_platform"
+        assert h1.platform == "group_platform"
+        g1.username = "group_username"
+        assert h1.username == "group_username"
+        g1.password = "group_password"
+        assert h1.password == "group_password"
+        g1.port = 9999
+        assert h1.port == 9999
+
+        h1.hostname = "alt_hostname"
+        assert h1.hostname == "alt_hostname"
+        h1.platform = "alt_platform"
+        assert h1.platform == "alt_platform"
+        h1.username = "alt_username"
+        assert h1.username == "alt_username"
+        h1.password = "alt_password"
+        assert h1.password == "alt_password"
+        h1.port = 9998
+        assert h1.port == 9998