Don't store the state in the charm

charms/worker/k8s/charmcraft.yaml

@@ -161,32 +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: ""
+      default: "/var/snap/k8s/common/rawfile-storage"
       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
+      default: Delete
       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:
-      type: boolean
-      description: |
-        Set the local storage class as the default storage class. This is only
-        used if local-storage.enabled is set to true.
 
 actions:
   get-kubeconfig:

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(), cluster_config={})
+        self._stored.set_default(is_dying=False, cluster_name=str())
 
         self.cos_agent = COSAgentProvider(
             self,
@@ -379,10 +379,11 @@ def _get_cluster_config_from_charm_config(self) -> UserFacingClusterConfig:
             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"),
+            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"),
+            # Note(ben): set_default is intentionally omitted, see:
+            # https://github.com/canonical/k8s-operator/pull/169/files#r1847378214
         )
 
         return UserFacingClusterConfig(
@@ -415,16 +416,20 @@ def _update_cluster_config(self):
         status.add(ops.MaintenanceStatus("Updating cluster configuration"))
         log.info("Updating cluster configuration")
 
-        cluster_config = self._get_cluster_config_from_charm_config()
+        charm_cluster_config = self._get_cluster_config_from_charm_config()
+        snap_cluster_config = self.api_manager.get_cluster_status().metadata.status.config
 
-        if self._stored.cluster_config == cluster_config:
+        if snap_cluster_config == charm_cluster_config:
             return
 
-        update_request = UpdateClusterConfigRequest(config=cluster_config)
+        log.info(
+            "Snap config %s different from charm config %s. Updating snap config...",
+            snap_cluster_config,
+            charm_cluster_config,
+        )
+        update_request = UpdateClusterConfigRequest(config=charm_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.