feat: set --enforce-node-group-min-size flag

To change the number of replicas,
a user can set the min annotation to the desired number of replicas
and cluster-autoscaler will scale up the MachineDeployment.

Author: dkoshkin

charts/capi-runtime-extensions/templates/cluster-autoscaler/manifests/cluster-autoscaler-configmap.yaml

@@ -178,6 +178,7 @@ data:
             - --node-group-auto-discovery=clusterapi:clusterName=tmpl-clustername-tmpl,namespace=tmpl-clusternamespace-tmpl
             - --kubeconfig=/cluster/kubeconfig
             - --clusterapi-cloud-config-authoritative
+            - --enforce-node-group-min-size=true
             - --logtostderr=true
             - --stderrthreshold=info
             - --v=4

hack/addons/kustomize/cluster-autoscaler/helm-values.yaml

@@ -9,6 +9,10 @@ fullnameOverride: cluster-autoscaler-tmpl-clustername-tmpl
 
 cloudProvider: clusterapi
 
+# Always trigger a scale-out if replicas are less than the min.
+extraArgs:
+  enforce-node-group-min-size: true
+
 # Enable it to run in a 1 Node cluster.
 tolerations:
   - effect: NoSchedule