Downgrade coredns to 1.6.5 due to upgrade errors while migrating coredns configmap (Corefile) (#5960)

README.md

@@ -133,7 +133,7 @@ Note: Upstart/SysV init based OS types are not supported.
   - [cephfs-provisioner](https://github.com/kubernetes-incubator/external-storage) v2.1.0-k8s1.11
   - [rbd-provisioner](https://github.com/kubernetes-incubator/external-storage) v2.1.1-k8s1.11
   - [cert-manager](https://github.com/jetstack/cert-manager) v0.11.1
-  - [coredns](https://github.com/coredns/coredns) v1.6.9
+  - [coredns](https://github.com/coredns/coredns) v1.6.5
   - [ingress-nginx](https://github.com/kubernetes/ingress-nginx) v0.30.0
 
 Note: The list of validated [docker versions](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.16.md) was updated to 1.13.1, 17.03, 17.06, 17.09, 18.06, 18.09. kubeadm now properly recognizes Docker 18.09.0 and newer, but still treats 18.06 as the default supported version. The kubelet might break on docker's non-standard version numbering (it no longer uses semantic versioning). To ensure auto-updates don't break your cluster look into e.g. yum versionlock plugin or apt pin).

roles/download/defaults/main.yml

@@ -511,7 +511,9 @@ nginx_image_tag: 1.17
 haproxy_image_repo: "{{ docker_image_repo }}/library/haproxy"
 haproxy_image_tag: 1.9
 
-coredns_version: "1.6.9"
+# Coredns version should be supported by corefile-migration (or at least work with)
+# bundle with kubeadm; if not 'basic' upgrade can sometimes fail
+coredns_version: "1.6.5"
 coredns_image_repo: "{{ docker_image_repo }}/coredns/coredns"
 coredns_image_tag: "{{ coredns_version }}"
 

roles/kubernetes-apps/ansible/templates/coredns-config.yml.j2

@@ -22,17 +22,14 @@ data:
 {% endif %}
     .:53 {
         errors
-        health
+        health {
+            lameduck 5s
+        }
         ready
         kubernetes {{ dns_domain }} in-addr.arpa ip6.arpa {
           pods insecure
 {% if enable_coredns_k8s_endpoint_pod_names %}
           endpoint_pod_names
-{% endif %}
-{% if resolvconf_mode == 'host_resolvconf' and upstream_dns_servers is defined and upstream_dns_servers|length > 0 %}
-          upstream {{ upstream_dns_servers|join(' ') }}
-{% else %}
-          upstream /etc/resolv.conf
 {% endif %}
           fallthrough in-addr.arpa ip6.arpa
         }