Recently I upgraded Kubernetes cluster from version 1.5.3 to 1.6.1 using kubeadm
.
Now I would like to upgrade from version 1.6.1 to 1.6.2 but I'm facing this error:
[root@master ~]#kubeadm upgrade plan --v=5
I1113 14:14:31.046080 8368 plan.go:67] [upgrade/plan] verifying health of cluster
I1113 14:14:31.046233 8368 plan.go:68] [upgrade/plan] retrieving configuration from cluster
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
I1113 14:14:31.111668 8368 common.go:122] running preflight checks
[preflight] Running pre-flight checks.
I1113 14:14:31.111843 8368 preflight.go:78] validating if there are any unsupported CoreDNS plugins in the Corefile
I1113 14:14:31.143841 8368 preflight.go:103] validating if migration can be done for the current CoreDNS release.
[preflight] Some fatal errors occurred:
[ERROR CoreDNSUnsupportedPlugins]: start version '' not supported
[ERROR CoreDNSMigration]: start version '' not supported
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
It seems that kubeadm
is not able to resolve CoreDNS version.
Here is the CoreDNS config:
apiVersion: v1
data:
Corefile: |
.:53 {
errors
health
ready
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
fallthrough in-addr.arpa ip6.arpa
ttl 30
}
prometheus :9153
forward . /etc/resolv.conf
cache 30
loop
reload
loadbalance
}
kind: ConfigMap
metadata:
creationTimestamp: "2018-12-15T00:02:45Z"
name: coredns
namespace: kube-system
resourceVersion: "45537229"
selfLink: /api/v1/namespaces/kube-system/configmaps/coredns
uid: c01fbb58-fffc-11e8-9a01-005056a31666
From where it is reading the version number? Or what can I do to solve this error?