Add some backward compatability for GKE.

(cherry picked from commit b07515c5ea)

cluster/saltbase/salt/generate-cert/init.sls

@@ -43,3 +43,33 @@ kubernetes-cert:
     - user: root
     - group: root
     - shell: /bin/bash
+
+# These are introduced to ensure backwards compatability with older gcloud tools in GKE
+kubernetes-old-key:
+  file.copy:
+    - name: /usr/share/nginx/kubecfg.key
+    - source: /srv/kubernetes/kubecfg.key
+    - makedirs: True
+    - preserve: True
+    - require:
+      - cmd: kubernetes-cert
+
+
+kubernetes-old-cert:
+  file.copy:
+    - name: /usr/share/nginx/kubecfg.crt
+    - source: /srv/kubernetes/kubecfg.crt
+    - makedirs: True
+    - preserve: True
+    - require:
+      - cmd: kubernetes-cert
+
+
+kubernetes-old-ca:
+  file.copy:
+    - name: /usr/share/nginx/ca.crt
+    - source: /srv/kubernetes/ca.crt
+    - makedirs: True
+    - preserve: True
+    - require:
+      - cmd: kubernetes-cert