[magnum-k8s] Add new config options

Add new config options to the charm so that
users can point to another capi helm repository.

Add config option api_resources to override versions or
names of the cluster api resources. The option
defaults to the ones used by canonical k8s capi
deployment.

Add config option allowed_network_drivers to specify the
CNI that are supported by the capi helm chart. Defaults
to the cilium driver that is supported by Canonical k8s

Change-Id: I6e498ef98391017b4d8175a6a044864dcbff6306
Signed-off-by: Hemanth Nakkina <hemanth.nakkina@canonical.com>

charms/magnum-k8s/charmcraft.yaml

@@ -37,6 +37,39 @@ config:
       description: |
         Kubeconfig to connect to Cluster API management cluster.
         The value should be juju secret.
+    helm_chart_repo:
+      default: "''"
+      type: string
+      description: |
+        The helm chart repository path that hosts the capi helm chart.
+
+        In case of OCI registry, set the repo path to "''".
+        Setting the option to "" will leave the magnum-capi-helm
+        driver option empty and uses defaults from the driver.
+
+    helm_chart_name:
+      default: oci://ghcr.io/canonical/charts/openstack-ck8s-cluster
+      type: string
+      description: |
+        Name of the helm chart to use from the repo specified.
+
+        In case of OCI registry, set the registry path as helm_chart_name
+    capi_api_resources:
+      default: '{"K8sControlPlane": {"api_version": "controlplane.cluster.x-k8s.io/v1beta2", "plural_name": "ck8scontrolplanes"}, "OpenstackCluster": {"api_version": "infrastructure.cluster.x-k8s.io/v1beta1"}}'
+      type: string
+      description: |
+        Override api resources provided by magnum-capi-helm driver.
+        Value should be a dictionary in string format
+
+        Defaults to settings required to support canonical k8s
+    allowed_network_drivers:
+      default: cilium
+      type: string
+      description: |
+        Comma separated list of allowed CNI that can be deployed on
+        Workload clusters.
+        Supported drivers for canonical k8s are cilium
+
 
 containers:
   magnum-api:

charms/magnum-k8s/src/templates/magnum.conf.j2

@@ -69,13 +69,12 @@ ca_file = /usr/local/share/ca-certificates/ca-bundle.pem
 driver = log
 
 [cluster_template]
-kubernetes_allowed_network_drivers = cilium
+kubernetes_allowed_network_drivers = {{ options.allowed_network_drivers }}
 
 [capi_helm]
 kubeconfig_file = /etc/magnum/kubeconfig
-# Empty repo so that helm chart can be downloaded from OCI registry
-helm_chart_repo = ""
-helm_chart_name = oci://ghcr.io/canonical/charts/openstack-ck8s-cluster
+helm_chart_repo = {{ options.helm_chart_repo }}
+helm_chart_name = {{ options.helm_chart_name }}
 default_helm_chart_version = 0.1.0
-api_resources = {"K8sControlPlane": {"api_version": "controlplane.cluster.x-k8s.io/v1beta2", "plural_name": "ck8scontrolplanes"}, "OpenstackCluster": {"api_version": "infrastructure.cluster.x-k8s.io/v1beta1"}}
+api_resources = {{ options.capi_api_resources }}
 k8s_control_plane_resource_conditions = MachinesReady,Ready,ControlPlaneComponentsHealthy