Fixing ingress controller daemonset on k8s < 1.9

cluster/juju/layers/kubernetes-worker/reactive/kubernetes_worker.py

@@ -746,6 +746,10 @@ def launch_default_ingress_controller():
         else:
             context['ingress_image'] = \
                 "k8s.gcr.io/nginx-ingress-controller:0.9.0-beta.15" # noqa
+    if get_version('kubelet') < (1, 9):
+        context['daemonset_api_version'] = 'extensions/v1beta1'
+    else:
+        context['daemonset_api_version'] = 'apps/v1beta2'
     context['juju_application'] = hookenv.service_name()
     manifest = addon_path.format('ingress-daemon-set.yaml')
     render('ingress-daemon-set.yaml', manifest, context)

cluster/juju/layers/kubernetes-worker/templates/ingress-daemon-set.yaml

@@ -127,7 +127,7 @@ kind: ConfigMap
 metadata:
   name: nginx-load-balancer-{{ juju_application }}-conf
 ---
-apiVersion: apps/v1beta2
+apiVersion: {{ daemonset_api_version }}
 kind: DaemonSet
 metadata:
   name: nginx-ingress-{{ juju_application }}-controller