Add secret configurations (#46)

examples/django/charm/charmcraft.yaml

@@ -48,6 +48,14 @@ config:
         for any other security related needs by your Django application. This configuration
         will set the DJANGO_SECRET_KEY environment variable.
       type: string
+    django-secret-key-id:
+      description: >-
+        This configuration is similar to `django-secret-key`, but instead accepts a Juju user secret ID. 
+        The secret should contain a single key, "value", which maps to the actual Django secret key. 
+        To create the secret, run the following command: 
+        `juju add-secret my-django-secret-key value=<secret-string> && juju grant-secret my-django-secret-key django-k8s`,
+        and use the outputted secret ID to configure this option.
+      type: secret
     webserver-keepalive:
       description: Time in seconds for webserver to wait for requests on a Keep-Alive
         connection.

examples/fastapi/charm/charmcraft.yaml

@@ -47,6 +47,14 @@ config:
       type: string
       description: Long secret you can use for sessions, csrf or any other thing where
          you need a random secret shared by all units
+    app-secret-key-id:
+      type: secret
+      description: >-
+        This configuration is similar to `app-secret-key`, but instead accepts a Juju user secret ID. 
+        The secret should contain a single key, "value", which maps to the actual secret key. 
+        To create the secret, run the following command: 
+        `juju add-secret my-secret-key value=<secret-string> && juju grant-secret my-secret-key fastapi-k8s`,
+        and use the outputted secret ID to configure this option.
     user-defined-config:
       type: string
       description: Example of a user defined configuration.

examples/flask/charmcraft.yaml

@@ -55,6 +55,14 @@ config:
         will set the FLASK_SECRET_KEY environment variable. Run `app.config.from_prefixed_env()`
         in your Flask application in order to receive this configuration.
       type: string
+    flask-secret-key-id:
+      description: >-
+        This configuration is similar to `flask-secret-key`, but instead accepts a Juju user secret ID. 
+        The secret should contain a single key, "value", which maps to the actual Flask secret key. 
+        To create the secret, run the following command: 
+        `juju add-secret my-flask-secret-key value=<secret-string> && juju grant-secret my-flask-secret-key flask-k8s`,
+        and use the outputted secret ID to configure this option.
+      type: secret
     flask-session-cookie-secure:
       description: Set the secure attribute in the Flask application cookies. This
         configuration will set the FLASK_SESSION_COOKIE_SECURE environment variable.
@@ -74,6 +82,9 @@ config:
     webserver-workers:
       description: The number of webserver worker processes for handling requests.
       type: int
+    secret-test:
+      description: A test configuration option for testing user provided Juju secrets.
+      type: secret
 containers:
   flask-app:
     resource: flask-app-image

examples/go/charm/charmcraft.yaml

@@ -38,6 +38,14 @@ config:
       type: string
       description: Long secret you can use for sessions, csrf or any other thing where
          you need a random secret shared by all units
+    app-secret-key-id:
+      type: secret
+      description: >-
+        This configuration is similar to `app-secret-key`, but instead accepts a Juju user secret ID. 
+        The secret should contain a single key, "value", which maps to the actual secret key. 
+        To create the secret, run the following command: 
+        `juju add-secret my-secret-key value=<secret-string> && juju grant-secret my-secret-key go-k8s`,
+        and use the outputted secret ID to configure this option.
     user-defined-config:
       type: string
       description: Example of a user defined configuration.

paas_app_charmer/app.py

@@ -2,7 +2,7 @@
 # See LICENSE file for licensing details.
 
 """Provide the base generic class to represent the application."""
-
+import collections
 import json
 import logging
 import pathlib
@@ -133,9 +133,16 @@ def gen_environment(self) -> dict[str, str]:
         Returns:
             A dictionary representing the application environment variables.
         """
-        config = self._charm_state.app_config
         prefix = self.configuration_prefix
-        env = {f"{prefix}{k.upper()}": encode_env(v) for k, v in config.items()}
+        env = {}
+        for app_config_key, app_config_value in self._charm_state.app_config.items():
+            if isinstance(app_config_value, collections.abc.Mapping):
+                for k, v in app_config_value.items():
+                    env[f"{prefix}{app_config_key.upper()}_{k.replace('-', '_').upper()}"] = (
+                        encode_env(v)
+                    )
+            else:
+                env[f"{prefix}{app_config_key.upper()}"] = encode_env(app_config_value)
 
         framework_config = self._charm_state.framework_config
         framework_config_prefix = self.framework_config_prefix

paas_app_charmer/charm.py

@@ -4,6 +4,7 @@
 """The base charm class for all application charms."""
 import abc
 import logging
+import typing
 
 import ops
 from charms.data_platform_libs.v0.data_interfaces import DatabaseRequiresEvent
@@ -21,7 +22,7 @@
 from paas_app_charmer.observability import Observability
 from paas_app_charmer.rabbitmq import RabbitMQRequires
 from paas_app_charmer.secret_storage import KeySecretStorage
-from paas_app_charmer.utils import build_validation_error_message
+from paas_app_charmer.utils import build_validation_error_message, config_get_with_secret
 
 logger = logging.getLogger(__name__)
 
@@ -143,6 +144,7 @@ def __init__(self, framework: ops.Framework, framework_name: str) -> None:
             self._on_secret_storage_relation_changed,
         )
         self.framework.observe(self.on.update_status, self._on_update_status)
+        self.framework.observe(self.on.secret_changed, self._on_secret_changed)
         for database, database_requirer in self._database_requirers.items():
             self.framework.observe(
                 database_requirer.on.database_created,
@@ -173,7 +175,14 @@ def get_framework_config(self) -> BaseModel:
         """
         # Will raise an AttributeError if it the attribute framework_config_class does not exist.
         framework_config_class = self.framework_config_class
-        config = dict(self.config.items())
+        charm_config = {k: config_get_with_secret(self, k) for k in self.config.keys()}
+        config = typing.cast(
+            dict,
+            {
+                k: v.get_content(refresh=True) if isinstance(v, ops.Secret) else v
+                for k, v in charm_config.items()
+            },
+        )
         try:
             return framework_config_class.model_validate(config)
         except ValidationError as exc:
@@ -186,12 +195,13 @@ def _container(self) -> Container:
         return self.unit.get_container(self._workload_config.container_name)
 
     @block_if_invalid_config
-    def _on_config_changed(self, _event: ops.EventBase) -> None:
-        """Configure the application pebble service layer.
+    def _on_config_changed(self, _: ops.EventBase) -> None:
+        """Configure the application pebble service layer."""
+        self.restart()
 
-        Args:
-            _event: the config-changed event that triggers this callback function.
-        """
+    @block_if_invalid_config
+    def _on_secret_changed(self, _: ops.EventBase) -> None:
+        """Configure the application Pebble service layer."""
         self.restart()
 
     @block_if_invalid_config
@@ -212,12 +222,8 @@ def _on_rotate_secret_key_action(self, event: ops.ActionEvent) -> None:
         self.restart()
 
     @block_if_invalid_config
-    def _on_secret_storage_relation_changed(self, _event: ops.RelationEvent) -> None:
-        """Handle the secret-storage-relation-changed event.
-
-        Args:
-            _event: the action event that triggers this callback.
-        """
+    def _on_secret_storage_relation_changed(self, _: ops.RelationEvent) -> None:
+        """Handle the secret-storage-relation-changed event."""
         self.restart()
 
     def update_app_and_unit_status(self, status: ops.StatusBase) -> None:
@@ -328,9 +334,16 @@ def _create_charm_state(self) -> CharmState:
         saml_relation_data = None
         if self._saml and (saml_data := self._saml.get_relation_data()):
             saml_relation_data = saml_data.to_relation_data()
-
+        charm_config = {k: config_get_with_secret(self, k) for k in self.config.keys()}
+        config = typing.cast(
+            dict,
+            {
+                k: v.get_content(refresh=True) if isinstance(v, ops.Secret) else v
+                for k, v in charm_config.items()
+            },
+        )
         return CharmState.from_charm(
-            charm=self,
+            config=config,
             framework=self._framework_name,
             framework_config=self.get_framework_config(),
             secret_storage=self._secret_storage,
@@ -360,67 +373,67 @@ def _on_update_status(self, _: ops.HookEvent) -> None:
             self.restart()
 
     @block_if_invalid_config
-    def _on_mysql_database_database_created(self, _event: DatabaseRequiresEvent) -> None:
+    def _on_mysql_database_database_created(self, _: DatabaseRequiresEvent) -> None:
         """Handle mysql's database-created event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_mysql_database_endpoints_changed(self, _event: DatabaseRequiresEvent) -> None:
+    def _on_mysql_database_endpoints_changed(self, _: DatabaseRequiresEvent) -> None:
         """Handle mysql's endpoints-changed event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_mysql_database_relation_broken(self, _event: ops.RelationBrokenEvent) -> None:
+    def _on_mysql_database_relation_broken(self, _: ops.RelationBrokenEvent) -> None:
         """Handle mysql's relation-broken event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_postgresql_database_database_created(self, _event: DatabaseRequiresEvent) -> None:
+    def _on_postgresql_database_database_created(self, _: DatabaseRequiresEvent) -> None:
         """Handle postgresql's database-created event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_postgresql_database_endpoints_changed(self, _event: DatabaseRequiresEvent) -> None:
+    def _on_postgresql_database_endpoints_changed(self, _: DatabaseRequiresEvent) -> None:
         """Handle mysql's endpoints-changed event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_postgresql_database_relation_broken(self, _event: ops.RelationBrokenEvent) -> None:
+    def _on_postgresql_database_relation_broken(self, _: ops.RelationBrokenEvent) -> None:
         """Handle postgresql's relation-broken event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_mongodb_database_database_created(self, _event: DatabaseRequiresEvent) -> None:
+    def _on_mongodb_database_database_created(self, _: DatabaseRequiresEvent) -> None:
         """Handle mongodb's database-created event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_mongodb_database_endpoints_changed(self, _event: DatabaseRequiresEvent) -> None:
+    def _on_mongodb_database_endpoints_changed(self, _: DatabaseRequiresEvent) -> None:
         """Handle mysql's endpoints-changed event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_mongodb_database_relation_broken(self, _event: ops.RelationBrokenEvent) -> None:
+    def _on_mongodb_database_relation_broken(self, _: ops.RelationBrokenEvent) -> None:
         """Handle postgresql's relation-broken event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_redis_relation_updated(self, _event: DatabaseRequiresEvent) -> None:
+    def _on_redis_relation_updated(self, _: DatabaseRequiresEvent) -> None:
         """Handle redis's database-created event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_s3_credential_changed(self, _event: ops.HookEvent) -> None:
+    def _on_s3_credential_changed(self, _: ops.HookEvent) -> None:
         """Handle s3 credentials-changed event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_s3_credential_gone(self, _event: ops.HookEvent) -> None:
+    def _on_s3_credential_gone(self, _: ops.HookEvent) -> None:
         """Handle s3 credentials-gone event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_saml_data_available(self, _event: ops.HookEvent) -> None:
+    def _on_saml_data_available(self, _: ops.HookEvent) -> None:
         """Handle saml data available event."""
         self.restart()
 
@@ -440,16 +453,16 @@ def _on_pebble_ready(self, _: ops.PebbleReadyEvent) -> None:
         self.restart()
 
     @block_if_invalid_config
-    def _on_rabbitmq_connected(self, _event: ops.HookEvent) -> None:
+    def _on_rabbitmq_connected(self, _: ops.HookEvent) -> None:
         """Handle rabbitmq connected event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_rabbitmq_ready(self, _event: ops.HookEvent) -> None:
+    def _on_rabbitmq_ready(self, _: ops.HookEvent) -> None:
         """Handle rabbitmq ready event."""
         self.restart()
 
     @block_if_invalid_config
-    def _on_rabbitmq_departed(self, _event: ops.HookEvent) -> None:
+    def _on_rabbitmq_departed(self, _: ops.HookEvent) -> None:
         """Handle rabbitmq departed event."""
         self.restart()

paas_app_charmer/charm_state.py

@@ -9,7 +9,6 @@
 from dataclasses import dataclass, field
 from typing import Optional
 
-import ops
 from charms.data_platform_libs.v0.data_interfaces import DatabaseRequires
 from pydantic import BaseModel, Extra, Field, ValidationError, ValidationInfo, field_validator
 
@@ -52,7 +51,7 @@ def __init__(  # pylint: disable=too-many-arguments
         *,
         framework: str,
         is_secret_storage_ready: bool,
-        app_config: dict[str, int | str | bool] | None = None,
+        app_config: dict[str, int | str | bool | dict[str, str]] | None = None,
         framework_config: dict[str, int | str] | None = None,
         secret_key: str | None = None,
         integrations: "IntegrationsState | None" = None,
@@ -81,7 +80,7 @@ def __init__(  # pylint: disable=too-many-arguments
     def from_charm(  # pylint: disable=too-many-arguments
         cls,
         *,
-        charm: ops.CharmBase,
+        config: dict[str, bool | int | float | str | dict[str, str]],
         framework: str,
         framework_config: BaseModel,
         secret_storage: KeySecretStorage,
@@ -95,7 +94,7 @@ def from_charm(  # pylint: disable=too-many-arguments
         """Initialize a new instance of the CharmState class from the associated charm.
 
         Args:
-            charm: The charm instance associated with this state.
+            config: The charm configuration.
             framework: The framework name.
             framework_config: The framework specific configurations.
             secret_storage: The secret storage manager associated with the charm.
@@ -111,7 +110,7 @@ def from_charm(  # pylint: disable=too-many-arguments
         """
         app_config = {
             k.replace("-", "_"): v
-            for k, v in charm.config.items()
+            for k, v in config.items()
             if not any(k.startswith(prefix) for prefix in (f"{framework}-", "webserver-", "app-"))
         }
         app_config = {
@@ -128,7 +127,7 @@ def from_charm(  # pylint: disable=too-many-arguments
         return cls(
             framework=framework,
             framework_config=framework_config.dict(exclude_none=True),
-            app_config=typing.cast(dict[str, str | int | bool], app_config),
+            app_config=typing.cast(dict[str, str | int | bool | dict[str, str]], app_config),
             secret_key=(
                 secret_storage.get_secret_key() if secret_storage.is_initialized else None
             ),
@@ -163,7 +162,7 @@ def framework_config(self) -> dict[str, str | int | bool]:
         return self._framework_config
 
     @property
-    def app_config(self) -> dict[str, str | int | bool]:
+    def app_config(self) -> dict[str, str | int | bool | dict[str, str]]:
         """Get the value of user-defined application configurations.
 
         Returns:

paas_app_charmer/django/charm.py

@@ -8,27 +8,31 @@
 import typing
 
 import ops
-from pydantic import BaseModel, Extra, Field, validator
+from pydantic import ConfigDict, Field, validator
 
 from paas_app_charmer._gunicorn.charm import GunicornBase
+from paas_app_charmer.framework import FrameworkConfig
 
 logger = logging.getLogger(__name__)
 
 
-class DjangoConfig(BaseModel, extra=Extra.ignore):
+class DjangoConfig(FrameworkConfig):
     """Represent Django builtin configuration values.
 
     Attrs:
         debug: whether Django debug mode is enabled.
         secret_key: a secret key that will be used for security related needs by your
             Django application.
         allowed_hosts: a list of host/domain names that this Django site can serve.
+        model_config: Pydantic model configuration.
     """
 
     debug: bool | None = Field(alias="django-debug", default=None)
     secret_key: str | None = Field(alias="django-secret-key", default=None, min_length=1)
     allowed_hosts: str | None = Field(alias="django-allowed-hosts", default=[])
 
+    model_config = ConfigDict(extra="ignore")
+
     @validator("allowed_hosts")
     @classmethod
     def allowed_hosts_to_list(cls, value: str | None) -> typing.List[str]: