coredns: plugin/rewrite Not working in k8s

Hi.

CoreDNS version: 1.6.0 Kubernetes version: v1.15.3 (Bare metal, installed via kubespray).

I try to use rewrite plugin. I add to ConfigMap core dns:

apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
        log
        errors
        health
        rewrite stop {
          name regex (.*)\.my\.domain\.$ {1}.navigator32-services-stage.svc.cluster.local
          answer name (.*)\.navigator32-services-stage\.svc\.cluster\.local\.$ {1}.my.domain
        }  
        ready
        # rewrite name nats-stage-client.my.domain nats-stage-client.navigator32-services-stage.svc.cluster.local
        kubernetes cluster.local in-addr.arpa ip6.arpa {
          pods insecure
          upstream /etc/resolv.conf
          fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . /etc/resolv.conf {
          prefer_udp
        }
        cache 30
        loop
        reload
        loadbalance
    }

I apply this manifest and restart coredns.

Then I try command (for example): host nats-stage-client.my.domain

and I see in logs:

.:53
2019-09-23T13:42:06.222Z [INFO] plugin/reload: Running configuration MD5 = daa664635e18fdc499460ac35f7d5650
2019-09-23T13:42:06.223Z [INFO] CoreDNS-1.6.0
2019-09-23T13:42:06.223Z [INFO] linux/amd64, go1.12.7, 0a218d3
CoreDNS-1.6.0
linux/amd64, go1.12.7, 0a218d3
2019-09-23T14:17:21.942Z [INFO] 10.233.122.0:37076 - 58005 "A IN nats-stage-client.my.domain.default.svc.cluster.local. tcp 71 false 65535" NXDOMAIN qr,aa,rd 164 0.000288025s
2019-09-23T14:17:21.947Z [INFO] 10.233.122.0:37076 - 23634 "A IN nats-stage-client.my.domain.svc.cluster.local. tcp 63 false 65535" NXDOMAIN qr,aa,rd 156 0.002472497s
2019-09-23T14:17:21.949Z [INFO] 10.233.122.0:37076 - 10253 "A IN nats-stage-client.my.domain.cluster.local. tcp 59 false 65535" NXDOMAIN qr,aa,rd 152 0.000340663s

I see that rewrite is not work. What could be the problem?

Thanks.

About this issue

Original URL
State: closed
Created 5 years ago
Comments: 29 (15 by maintainers)

Most upvoted comments

I came up with the following solution: need to change configmap of nodelocaldns (kubectl get configmap nodelocaldns -n kube-system -o yaml > nodelocaldns.yaml and change

.......

.:53 {
        errors
        cache 30
        reload 
        loop
        bind 169.254.25.10
        forward . /etc/resolv.conf
        prometheus :9253
    }

.....

.:53 {
        errors
        cache 30
        reload 
        loop
        bind 169.254.25.10
        forward . 10.233.0.3 {
            force_tcp
        }
        prometheus :9253
    }

then apply it kubectl apply -f nodelocaldns.yaml,

and after that the rewrite rules start to work.

SergeSpinoza on Sep 24, 2019