config[x] with type:secret returns a Secret.

ops/__init__.py

@@ -55,6 +55,7 @@
     'CollectMetricsEvent',
     'CollectStatusEvent',
     'ConfigChangedEvent',
+    'ConfigMeta',
     'ContainerBase',
     'ContainerMeta',
     'ContainerStorageMeta',
@@ -198,6 +199,7 @@
     CollectMetricsEvent,
     CollectStatusEvent,
     ConfigChangedEvent,
+    ConfigMeta,
     ContainerBase,
     ContainerMeta,
     ContainerStorageMeta,

ops/model.py

@@ -118,7 +118,7 @@ def __init__(self, meta: 'ops.charm.CharmMeta', backend: '_ModelBackend',
         relations: Dict[str, 'ops.RelationMeta'] = meta.relations
         self._relations = RelationMapping(relations, self.unit, self._backend, self._cache,
                                           broken_relation_id=broken_relation_id)
-        self._config = ConfigData(self._backend)
+        self._config = ConfigData(self._backend, meta.config)
         resources: Iterable[str] = meta.resources
         self._resources = Resources(list(resources), self._backend)
         self._pod = Pod(self._backend)
@@ -1724,11 +1724,20 @@ class ConfigData(LazyMapping):
     This class should not be instantiated directly. It should be accessed via :attr:`Model.config`.
     """
 
-    def __init__(self, backend: '_ModelBackend'):
+    def __init__(self, backend: '_ModelBackend',
+                 config: Optional[Dict[str, 'ops.ConfigMeta']] = None):
         self._backend = backend
+        self._config = config
 
     def _load(self):
-        return self._backend.config_get()
+        data = self._backend.config_get()
+        if self._config:
+            # Convert any type:secret options to Secret objects.
+            # The simple types (bool, int, float, str) are correctly typed in the JSON.
+            for option in self._config.values():
+                if option.type == "secret" and option.name in data:
+                    data[option.name] = Secret(self._backend, data[option.name])
+        return data
 
 
 class StatusBase:

ops/testing.py

@@ -60,7 +60,7 @@
 from ops import charm, framework, model, pebble, storage
 from ops._private import yaml
 from ops.charm import CharmBase, CharmMeta, RelationRole
-from ops.model import Container, RelationNotFoundError, _ConfigOption, _NetworkDict
+from ops.model import Container, RelationNotFoundError, Secret, _ConfigOption, _NetworkDict
 from ops.pebble import ExecProcess
 
 ReadableBuffer = Union[bytes, str, StringIO, BytesIO, BinaryIO]
@@ -1307,7 +1307,7 @@ def _emit_relation_changed(self, relation_id: int, app_or_unit: str):
 
     def _update_config(
             self,
-            key_values: Optional[Mapping[str, Union[str, int, float, bool]]] = None,
+            key_values: Optional[Mapping[str, Union[str, int, float, bool, Secret]]] = None,
             unset: Iterable[str] = (),
     ) -> None:
         """Update the config as seen by the charm.
@@ -1330,6 +1330,9 @@ def _update_config(
             for key, value in key_values.items():
                 if key in config._defaults:
                     if value is not None:
+                        if self._meta.config[key].type == 'secret' and isinstance(value, str):
+                            # Promote this to an actual Secret object.
+                            value = Secret(self._backend, value)
                         config._config_set(key, value)
                 else:
                     raise ValueError(f"unknown config option: '{key}'")
@@ -1344,7 +1347,7 @@ def _update_config(
 
     def update_config(
             self,
-            key_values: Optional[Mapping[str, Union[str, int, float, bool]]] = None,
+            key_values: Optional[Mapping[str, Union[str, int, float, bool, Secret]]] = None,
             unset: Iterable[str] = (),
     ) -> None:
         """Update the config as seen by the charm.

test/test_model.py

@@ -59,6 +59,10 @@ def setUp(self):
                 type: int
             qux:
                 type: boolean
+            secretfoo:
+                type: secret
+            secretbar:
+                type: secret
         ''')
         self.addCleanup(self.harness.cleanup)
         self.relation_id_db0 = self.harness.add_relation('db0', 'db')
@@ -618,11 +622,17 @@ def test_relation_no_units(self):
 
     def test_config(self):
         self.harness._get_backend_calls(reset=True)
-        self.harness.update_config({'foo': 'foo', 'bar': 1, 'qux': True})
+        secretfoo_id = self.harness.add_user_secret({"password": "xxxxxxxx"})
+        secretbar_id = self.harness.add_user_secret({"certificate": "xxxxxxxx"})
+        secretbar = self.model.get_secret(id=secretbar_id)
+        self.harness.update_config({'foo': 'foo', 'bar': 1, 'qux': True,
+                                   'secretfoo': secretfoo_id, 'secretbar': secretbar})
         self.assertEqual(self.model.config, {
             'foo': 'foo',
             'bar': 1,
             'qux': True,
+            'secretfoo': self.model.get_secret(id=secretfoo_id),
+            'secretbar': secretbar,
         })
         with self.assertRaises(TypeError):
             # Confirm that we cannot modify config values.