Add support for arm64 to juju charms.

cluster/juju/layers/kubernetes-worker/metadata.yaml

@@ -37,6 +37,10 @@ resources:
     type: file
     filename: cni.tgz
     description: CNI plugins for amd64
+  cni-arm64:
+    type: file
+    filename: cni.tgz
+    description: CNI plugins for arm64
   cni-s390x:
     type: file
     filename: cni.tgz

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

@@ -705,6 +705,9 @@ def launch_default_ingress_controller():
         if context['arch'] == 's390x':
             context['defaultbackend_image'] = \
                 "k8s.gcr.io/defaultbackend-s390x:1.4"
+        elif context['arch'] == 'arm64':
+            context['defaultbackend_image'] = \
+                "k8s.gcr.io/defaultbackend-arm64:1.4"
         else:
             context['defaultbackend_image'] = \
                 "k8s.gcr.io/defaultbackend:1.4"
@@ -728,6 +731,9 @@ def launch_default_ingress_controller():
         if context['arch'] == 's390x':
             context['ingress_image'] = \
                 "docker.io/cdkbot/nginx-ingress-controller-s390x:0.9.0-beta.13"
+        elif context['arch'] == 'arm64':
+            context['ingress_image'] = \
+                "gcr.io/google-containers/nginx-ingress-controller-arm64:0.9.0-beta.15" # noqa
         else:
             context['ingress_image'] = \
                 "k8s.gcr.io/nginx-ingress-controller:0.9.0-beta.15" # noqa