Subordinate charm config PoC

charms/worker/k8s/charmcraft.yaml

@@ -126,7 +126,7 @@ config:
       type: string
       description: |
         Labels can be used to organize and to select subsets of nodes in the
-        cluster. Declare node labels in key=value format, separated by spaces.      
+        cluster. Declare node labels in key=value format, separated by spaces.
     register-with-taints:
       type: string
       default: ""
@@ -178,6 +178,9 @@ provides:
     interface: containerd
   ceph-k8s-info:
     interface: kubernetes-info
+  feature:
+    interface: k8s-snap-feature
+    scope: container
 
 requires:
   etcd:

charms/worker/k8s/src/charm.py

@@ -21,6 +21,7 @@
 import socket
 import subprocess
 import uuid
+import json
 from functools import cached_property
 from pathlib import Path
 from time import sleep
@@ -38,6 +39,7 @@
 from charms.interface_external_cloud_provider import ExternalCloudProvider
 from charms.k8s.v0.k8sd_api_manager import (
     BootstrapConfig,
+    LoadBalancerConfig,
     ControlPlaneNodeJoinConfig,
     CreateClusterRequest,
     DNSConfig,
@@ -149,10 +151,47 @@ def __init__(self, *args):
         )
 
         self.framework.observe(self.on.update_status, self._on_update_status)
+        self.framework.observe(self.on.feature_relation_changed, self._on_feature_relation_changed)
+
         if self.is_control_plane:
             self.etcd = EtcdReactiveRequires(self)
             self.framework.observe(self.on.get_kubeconfig_action, self._get_external_kubeconfig)
 
+    def _on_feature_relation_changed(self, event: ops.RelationChangedEvent):
+        relation_data = event.relation.data.get(event.unit) #type: ignore
+        if not relation_data:
+            log.warning("No relation data found for unit %s", event.unit)
+            return
+
+        feature_name = relation_data.get("feature-name")
+        feature_version = relation_data.get("feature-version") # library version
+        feature_attributes = relation_data.get("feature-attributes")
+
+        feature_config_classes: Dict[str, type] = {
+            "load-balancer": LoadBalancerConfig,
+            "local-storage": LocalStorageConfig,
+        }
+
+        if feature_name and feature_version and feature_attributes:
+            feature_attributes = json.loads(feature_attributes)
+
+            config_class = feature_config_classes.get(feature_name)
+            if config_class:
+                feature_config = config_class(**feature_attributes)
+
+                feature_name = feature_name.replace("-", "_")
+                config = UserFacingClusterConfig(**{feature_name: feature_config})
+                update_request = UpdateClusterConfigRequest(config=config)
+                self.api_manager.update_cluster_config(update_request)
+
+                log.info("Got feature of type [%s], with version [%s] and attributes [%s]", feature_name, feature_version, json.dumps(feature_config.dict()))
+            else:
+                log.warning("Unsupported feature name: %s", feature_name)
+        else:
+            log.warning("Feature relation data is incomplete: %s", relation_data)
+
+        log.info("Relation %s changed: %s", event.relation.name, relation_data)
+
     def _k8s_info(self, event: ops.EventBase):
         """Send cluster information on the kubernetes-info relation.
 

redeploy.sh

@@ -0,0 +1,28 @@
+set -x
+
+DIR=$(realpath $(dirname "${0}"))
+LB_DIR=$DIR/../k8s-load-balancer
+
+echo "Run charmcraft pack for k8s"
+charmcraft pack -p charms/worker/k8s
+
+echo "Run charmcraft pack for k8s-load-balancer"
+cd $LB_DIR
+charmcraft pack
+
+cd $DIR
+
+echo "Removing k8s k8s-load-balancer relation..."
+juju remove-relation k8s k8s-load-balancer
+
+echo "Removing k8s-load-balancer application..."
+juju remove-application k8s-load-balancer
+
+echo "Refresh k8s application with new charm"
+juju refresh k8s --switch $DIR/k8s_ubuntu-20.04-amd64_ubuntu-22.04-amd64_ubuntu-24.04-amd64.charm --force-units --force
+
+echo "Refresh k8s-load-balancer application with new charm"
+juju deploy $LB_DIR/k8s-load-balancer_ubuntu-22.04-amd64.charm
+
+echo "Add relation"
+juju integrate k8s k8s-load-balancer