Add cluster config through charm config

charms/worker/k8s/charmcraft.yaml

@@ -161,31 +161,29 @@ config:
         CIDR to use for Kubernetes services. After deployment it is
         only possible to increase the size of the IP range. It is not possible to
         change or shrink the address range after deployment.
-    local-storage.enabled:
+    local_storage_enabled:
       type: boolean
-      default: true
       description: |
         Enable local storage provisioning. This will create a storage class
         named "local-storage" that uses the hostPath provisioner. This is
         useful for development and testing purposes. It is not recommended for
         production use.
-    local-storage.local-path:
+    local_storage_local_path:
       type: string
       default: ""
       description: |
         The path on the host where local storage will be provisioned. This
         path must be writable by the kubelet. This is only used if
         local-storage.enabled is set to true.
-    local-storage.reclaim-policy:
+    local_storage_reclaim_policy:
       type: string
       description: |
         The reclaim policy for local storage. This can be either "Delete" or
         "Retain". If set to "Delete", the storage will be deleted when the
         PersistentVolumeClaim is deleted. If set to "Retain", the storage will
         be retained when the PersistentVolumeClaim is deleted.
-    local-storage.set-default:
+    local_storage_set_default:
       type: boolean
-      default: false
       description: |
         Set the local storage class as the default storage class. This is only
         used if local-storage.enabled is set to true.

charms/worker/k8s/src/charm.py

@@ -133,7 +133,7 @@ def __init__(self, *args):
         self.labeller = LabelMaker(
             self, kubeconfig_path=self._internal_kubeconfig, kubectl=KUBECTL_PATH
         )
-        self._stored.set_default(is_dying=False, cluster_name=str(), annotations={})
+        self._stored.set_default(is_dying=False, cluster_name=str(), cluster_config={})
 
         self.cos_agent = COSAgentProvider(
             self,
@@ -296,7 +296,7 @@ def _bootstrap_k8s_snap(self):
         bootstrap_config = BootstrapConfig()
         self._configure_datastore(bootstrap_config)
         self._configure_cloud_provider(bootstrap_config)
-        self._configure_annotations(bootstrap_config)
+        self._configure_cluster_config(bootstrap_config)
         bootstrap_config.service_cidr = str(self.config["service-cidr"])
         bootstrap_config.control_plane_taints = str(self.config["register-with-taints"]).split()
         bootstrap_config.extra_sans = [_get_public_address()]
@@ -372,41 +372,59 @@ def _get_valid_annotations(self) -> Optional[dict]:
 
         return annotations
 
-    def _configure_annotations(self, config: BootstrapConfig):
-        """Configure the annotations for the Canonical Kubernetes cluster.
+    def _get_cluster_config_from_charm_config(self) -> UserFacingClusterConfig:
+        """Retrieve the cluster config from charm configuration.
+
+        Returns:
+            UserFacingClusterConfig: The expected cluster configuration.
+        """
+        local_storage = LocalStorageConfig(
+            enabled=self.config.get("local_storage_enabled"),
+            local_path=self.config.get("local_storage_local_path"),
+            reclaim_policy=self.config.get("local_storage_reclaim_policy"),
+            set_default=self.config.get("local_storage_set_default"),
+        )
+
+        return UserFacingClusterConfig(
+            local_storage=local_storage,
+            annotations=self._get_valid_annotations(),
+        )
+
+    def _configure_cluster_config(self, config: BootstrapConfig):
+        """Configure the cluster config for the Canonical Kubernetes cluster.
 
         Args:
             config (BootstrapConfig): Configuration object to bootstrap the cluster.
         """
-        annotations = self._get_valid_annotations()
-        if annotations is None:
-            return
-
         if not config.cluster_config:
-            config.cluster_config = UserFacingClusterConfig(annotations=annotations)
+            config.cluster_config = self._get_cluster_config_from_charm_config()
         else:
-            config.cluster_config.annotations = annotations
+            charm_cluster_config = self._get_cluster_config_from_charm_config()
+            # Merge the charm and user cluster configurations
+            # The existing configuration takes precedence over the charm configuration as
+            # this information is retrieved elsewhere (e.g. cloud-provider).
+            merged_data = {**charm_cluster_config.dict(), **config.cluster_config.dict()}
+            config.cluster_config = UserFacingClusterConfig(**merged_data)
 
     @status.on_error(
-        ops.BlockedStatus("Invalid Annotations"),
+        ops.BlockedStatus("Invalid Cluster configuration"),
         AssertionError,
     )
-    def _update_annotations(self):
-        """Update the annotations for the Canonical Kubernetes cluster."""
-        annotations = self._get_valid_annotations()
-        if annotations is None:
-            return
+    def _update_cluster_config(self):
+        """Update the cluster configuration for the Canonical Kubernetes cluster."""
+        status.add(ops.MaintenanceStatus("Updating cluster configuration"))
+        log.info("Updating cluster configuration")
 
-        status.add(ops.MaintenanceStatus("Updating Annotations"))
-        log.info("Updating Annotations")
+        cluster_config = self._get_cluster_config_from_charm_config()
 
-        if self._stored.annotations == annotations:
+        if self._stored.cluster_config == cluster_config:
             return
 
-        config = UserFacingClusterConfig(annotations=annotations)
-        update_request = UpdateClusterConfigRequest(config=config)
+        update_request = UpdateClusterConfigRequest(config=cluster_config)
         self.api_manager.update_cluster_config(update_request)
 
+        self._stored.cluster_config = cluster_config
+
     def _configure_datastore(self, config: Union[BootstrapConfig, UpdateClusterConfigRequest]):
         """Configure the datastore for the Kubernetes cluster.
 
@@ -737,7 +755,7 @@ def _reconcile(self, event: ops.EventBase):
             self._k8s_info(event)
             self._bootstrap_k8s_snap()
             self._enable_functionalities()
-            self._update_annotations()
+            self._update_cluster_config()
             self._create_cluster_tokens()
             self._create_cos_tokens()
             self._apply_cos_requirements()