I have 1 master and 4 minions all running on version 1.2.0. I am planning to upgrade them to 1.3.0. I want this done with minimal downtime.

So I did the following on one minion.

systemctl stop kubelet
yum update kubernetes-1.3.0-0.3.git86dc49a.el7
systemctl start kubelet

Once I bring up the service, i see the following ERROR.

Mar 28 20:36:55 csdp-e2e-kubernetes-minion-6 kubelet[9902]: E0328 20:36:55.215614    9902 kubelet.go:1222] Unable to register node "172.29.240.169" with API server: the body of the request was in an unknown format - accepted media types include: application/json, application/yaml
Mar 28 20:36:55 csdp-e2e-kubernetes-minion-6 kubelet[9902]: E0328 20:36:55.217612    9902 event.go:198] Server rejected event '&api.Event{TypeMeta:unversioned.TypeMeta{Kind:"", APIVersion:""}, ObjectMeta:api.ObjectMeta{Name:"172.29.240.169.14b01ded8fb2d07b", GenerateName:"", Namespace:"default", SelfLink:"", UID:"", ResourceVersion:"", Generation:0, CreationTimestamp:unversioned.Time{Time:time.Time{sec:0, nsec:0, loc:(*time.Location)(nil)}}, DeletionTimestamp:(*unversioned.Time)(nil), DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string(nil), OwnerReferences:[]api.OwnerReference(nil), Finalizers:[]string(nil)}, InvolvedObject:api.ObjectReference{Kind:"Node", Namespace:"", Name:"172.29.240.169", UID:"172.29.240.169", APIVersion:"", ResourceVersion:"", FieldPath:""}, Reason:"NodeHasSufficientDisk", Message:"Node 172.29.240.169 status is now: NodeHasSufficientDisk", Source:api.EventSource{Component:"kubelet", Host:"172.29.240.169"}, FirstTimestamp:unversioned.Time{Time:time.Time{sec:63626321182, nsec:814949499, loc:(*time.Location)(0x4c8a780)}}, LastTimestamp:unversioned.Time{Time:time.Time{sec:63626330215, nsec:213372890, loc:(*time.Location)(0x4c8a780)}}, Count:1278, Type:"Normal"}': 'the body of the request was in an unknown format - accepted media types include: application/json, application/yaml' (will not retry!)
Mar 28 20:36:55 csdp-e2e-kubernetes-minion-6 kubelet[9902]: E0328 20:36:55.246100    9902 event.go:198] Server rejected event '&api.Event{TypeMeta:unversioned.TypeMeta{Kind:"", APIVersion:""}, ObjectMeta:api.ObjectMeta{Name:"172.29.240.169.14b01ded8fb2fc88", GenerateName:"", Namespace:"default", SelfLink:"", UID:"", ResourceVersion:"", Generation:0, CreationTimestamp:unversioned.Time{Time:time.Time{sec:0, nsec:0, loc:(*time.Location)(nil)}}, DeletionTimestamp:(*unversioned.Time)(nil), DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string(nil), OwnerReferences:[]api.OwnerReference(nil), Finalizers:[]string(nil)}, InvolvedObject:api.ObjectReference{Kind:"Node", Namespace:"", Name:"172.29.240.169", UID:"172.29.240.169", APIVersion:"", ResourceVersion:"", FieldPath:""}, Reason:"NodeHasSufficientMemory", Message:"Node 172.29.240.169 status is now: NodeHasSufficientMemory", Source:api.EventSource{Component:"kubelet", Host:"172.29.240.169"}, FirstTimestamp:unversioned.Time{Time:time.Time{sec:63626321182, nsec:814960776, loc:(*time.Location)(0x4c8a780)}}, LastTimestamp:unversioned.Time{Time:time.Time{sec:63626330215, nsec:213381138, loc:(*time.Location)(0x4c8a780)}}, Count:1278, Type:"Normal"}': 'the body of the request was in an unknown format - accepted media types include: application/json, application/yaml' (will not retry!)

Is v1.2.0 incompatible with v1.3.0 ?

Seems like the issue is with JSON incompatibility ? application/json, application/yaml

From master standpoint ::

[root@kubernetes-master ~]# kubectl get nodes
NAME             STATUS     AGE
172.29.219.105   Ready      3h
172.29.240.146   Ready      3h
172.29.240.168   Ready      3h
172.29.240.169   NotReady   3h

The node that I upgraded is in NotReady state.