KS3.0之coredns和nodelocaldns配置

freemankevin

hongming

freemankevin File does not exist: /etc/add_hosts 应该是这个问题吧

freemankevin

[root@master1 ~]# cat  /etc/add_hosts
10.0.1.223  master1.cluster.local master1
10.0.1.224  master2.cluster.local master2
10.0.1.225  master3.cluster.local master3
10.0.1.209  node1.cluster.local node1
10.0.1.211  node2.cluster.local node2
10.0.1.212  node3.cluster.local node3
10.0.1.99  lb.kubesphere.local
10.0.1.185  harbor.dockerregistry.com
[root@master1 ~]# kubectl -n kube-system edit cm coredns
# Please edit the object below. Lines beginning with a '#' will be ignored,
# and an empty file will abort the edit. If an error occurs while saving this file will be
# reopened with the relevant failures.
#
apiVersion: v1
data:
  Corefile: |
    .:53 {
        errors
        health {
           lameduck 5s
        }
        hosts{
           10.0.1.223  master1.cluster.local master1
           10.0.1.224  master2.cluster.local master2
           10.0.1.225  master3.cluster.local master3
           10.0.1.209  node1.cluster.local node1
           10.0.1.211  node2.cluster.local node2
           10.0.1.212  node3.cluster.local node3
           10.0.1.99  lb.kubesphere.local
           10.0.1.185  harbor.dockerregistry.com
           fallthrough
        }
        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
        #forward . 10.233.0.3 {
        #    force_tcp
        #}
        cache 30
        loop
        reload
        loadbalance
    }
kind: ConfigMap
metadata:
  creationTimestamp: "2020-12-19T10:04:53Z"
  name: coredns
  namespace: kube-system
  resourceVersion: "42499"
"/tmp/kubectl-edit-2jjw7.yaml" 47L, 1374C written
configmap/coredns edited
[root@master1 ~]#

[root@master1 ~]#
[root@master1 ~]#
[root@master1 ~]# kubectl get pod -A|grep dns
kube-system                    coredns-564cdd5d55-7mbxn                             1/1     Running     0          91m
kube-system                    coredns-564cdd5d55-lfctb                             1/1     Running     0          91m
kube-system                    nodelocaldns-grvrk                                   1/1     Running     0          91m
kube-system                    nodelocaldns-k4w6g                                   1/1     Running     0          91m
kube-system                    nodelocaldns-kvb54                                   1/1     Running     0          91m
kube-system                    nodelocaldns-mnn2f                                   1/1     Running     0          91m
kube-system                    nodelocaldns-sd8fz                                   1/1     Running     0          91m
kube-system                    nodelocaldns-shjst                                   1/1     Running     0          91m
[root@master1 ~]# kubectl delete -n kube-system pod `kubectl get pod -A|grep dns|awk '{print $2}'`
pod "coredns-564cdd5d55-7mbxn" deleted
pod "coredns-564cdd5d55-lfctb" deleted
pod "nodelocaldns-grvrk" deleted
pod "nodelocaldns-k4w6g" deleted
pod "nodelocaldns-kvb54" deleted
pod "nodelocaldns-mnn2f" deleted
pod "nodelocaldns-sd8fz" deleted
pod "nodelocaldns-shjst" deleted
[root@master1 ~]# kubectl get pod -A|grep dns
kube-system                    coredns-564cdd5d55-b57mw                             0/1     CrashLoopBackOff   2          28s
kube-system                    coredns-564cdd5d55-tww96                             0/1     CrashLoopBackOff   2          28s
kube-system                    nodelocaldns-82w8t                                   1/1     Running            0          28s
kube-system                    nodelocaldns-bx8z6                                   1/1     Running            0          28s
kube-system                    nodelocaldns-cznmc                                   1/1     Running            0          28s
kube-system                    nodelocaldns-h4s7v                                   1/1     Running            0          28s
kube-system                    nodelocaldns-rk6rm                                   1/1     Running            0          28s
kube-system                    nodelocaldns-st5fk                                   1/1     Running            0          28s
[root@master1 ~]# kubectl logs -f -n kube-system coredns-564cdd5d55-b57mw
/etc/coredns/Corefile:6 - Error during parsing: Unknown directive 'hosts{'
[root@master1 ~]# kubectl -n kube-system edit cm coredns
# Please edit the object below. Lines beginning with a '#' will be ignored,
# and an empty file will abort the edit. If an error occurs while saving this file will be
# reopened with the relevant failures.
#
apiVersion: v1
data:
  Corefile: |
    .:53 {
        errors
        health {
           lameduck 5s
        }
        hosts {
           10.0.1.223  master1.cluster.local master1
           10.0.1.224  master2.cluster.local master2
           10.0.1.225  master3.cluster.local master3
           10.0.1.209  node1.cluster.local node1
           10.0.1.211  node2.cluster.local node2
           10.0.1.212  node3.cluster.local node3
           10.0.1.99  lb.kubesphere.local
           10.0.1.185  harbor.dockerregistry.com
           fallthrough
        }
        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
        #forward . 10.233.0.3 {
        #    force_tcp
        #}
        cache 30
        loop
        reload
        loadbalance
    }
kind: ConfigMap
metadata:
  creationTimestamp: "2020-12-19T10:04:53Z"
  name: coredns
  namespace: kube-system
  resourceVersion: "76280"
"/tmp/kubectl-edit-4czc0.yaml" 47L, 1375C written
configmap/coredns edited
[root@master1 ~]# kubectl delete -n kube-system pod `kubectl get pod -A|grep dns|awk '{print $2}'`
pod "coredns-564cdd5d55-b57mw" deleted
pod "coredns-564cdd5d55-tww96" deleted
pod "nodelocaldns-82w8t" deleted
pod "nodelocaldns-bx8z6" deleted
pod "nodelocaldns-cznmc" deleted
pod "nodelocaldns-h4s7v" deleted
pod "nodelocaldns-rk6rm" deleted
pod "nodelocaldns-st5fk" deleted
[root@master1 ~]# kubectl get pod -A|grep dns
kube-system                    coredns-564cdd5d55-ffcfv                             1/1     Running     0          18s
kube-system                    coredns-564cdd5d55-wxrjc                             1/1     Running     0          18s
kube-system                    nodelocaldns-22ccz                                   1/1     Running     0          18s
kube-system                    nodelocaldns-4ghrt                                   1/1     Running     0          18s
kube-system                    nodelocaldns-5xdgx                                   1/1     Running     0          18s
kube-system                    nodelocaldns-6k6fc                                   1/1     Running     0          18s
kube-system                    nodelocaldns-bf455                                   1/1     Running     0          18s
kube-system                    nodelocaldns-cjp4k                                   1/1     Running     0          18s
[root@master1 ~]# nslookup node1  -n 10.233.0.3
*** Invalid option: n
Server:		10.233.0.3
Address:	10.233.0.3#53

Name:	node1
Address: 10.0.1.209

freemankevin

供排错的伙伴参考：

COREDNS

[root@master1 ~]# kubectl -n kube-system get cm coredns -oyaml
apiVersion: v1
data:
  Corefile: |
    .:53 {
        errors
        health {
           lameduck 5s
        }
        hosts {
           10.0.1.223  master1.cluster.local master1
           10.0.1.224  master2.cluster.local master2
           10.0.1.225  master3.cluster.local master3
           10.0.1.209  node1.cluster.local node1
           10.0.1.211  node2.cluster.local node2
           10.0.1.212  node3.cluster.local node3
           10.0.1.99  lb.kubesphere.local
           10.0.1.185  harbor.dockerregistry.com
           fallthrough
        }
        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
        #forward . 10.233.0.3 {
        #    force_tcp
        #}
        cache 30
        loop
        reload
        loadbalance
    }
kind: ConfigMap
metadata:
  creationTimestamp: "2020-12-19T10:04:53Z"
  name: coredns
  namespace: kube-system
  resourceVersion: "77112"
  selfLink: /api/v1/namespaces/kube-system/configmaps/coredns
  uid: f53c6d73-842d-4c38-a0b0-9df3b5a74cc4

nodelocaldns

[root@master1 ~]# kubectl -n kube-system get cm nodelocaldns -oyaml
apiVersion: v1
data:
  Corefile: |
    cluster.local:53 {
        errors
        cache {
            success 9984 30
            denial 9984 5
        }
        reload
        loop
        bind 169.254.25.10
        forward . 10.233.0.3 {
            force_tcp
        }
        prometheus :9253
        health 169.254.25.10:9254
    }
    in-addr.arpa:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.25.10
        forward . 10.233.0.3 {
            force_tcp
        }
        prometheus :9253
    }
    ip6.arpa:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.25.10
        forward . 10.233.0.3 {
            force_tcp
        }
        prometheus :9253
    }
    .:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.25.10
        #forward . /etc/resolv.conf
        forward . 10.233.0.3 {
            force_tcp
        }
        prometheus :9253
    }
kind: ConfigMap
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"v1","data":{"Corefile":"cluster.local:53 {\n    errors\n    cache {\n        success 9984 30\n        denial 9984 5\n    }\n    reload\n    loop\n    bind 169.254.25.10\n    forward . 10.233.0.3 {\n        force_tcp\n    }\n    prometheus :9253\n    health 169.254.25.10:9254\n}\nin-addr.arpa:53 {\n    errors\n    cache 30\n    reload\n    loop\n    bind 169.254.25.10\n    forward . 10.233.0.3 {\n        force_tcp\n    }\n    prometheus :9253\n}\nip6.arpa:53 {\n    errors\n    cache 30\n    reload\n    loop\n    bind 169.254.25.10\n    forward . 10.233.0.3 {\n        force_tcp\n    }\n    prometheus :9253\n}\n.:53 {\n    errors\n    cache 30\n    reload\n    loop\n    bind 169.254.25.10\n    forward . /etc/resolv.conf\n prometheus :9253\n}\n"},"kind":"ConfigMap","metadata":{"annotations":{},"labels":{"addonmanager.kubernetes.io/mode":"EnsureExists"},"name":"nodelocaldns","namespace":"kube-system"}}
  creationTimestamp: "2020-12-19T10:05:15Z"
  labels:
    addonmanager.kubernetes.io/mode: EnsureExists
  name: nodelocaldns
  namespace: kube-system
  resourceVersion: "34304"
  selfLink: /api/v1/namespaces/kube-system/configmaps/nodelocaldns
  uid: df5d3c4f-bd1d-46ff-9891-eec753bec78a

改好后修改删除原POD以重启dns

[root@master1 ~]# kubectl delete -n kube-system pod `kubectl get pod -A|grep dns|awk '{print $2}'`

如果没有异常，pod会很快running

[root@master1 ~]# kubectl get pod -A|grep dns
kube-system                    coredns-564cdd5d55-ffcfv                             1/1     Running     0          10m
kube-system                    coredns-564cdd5d55-wxrjc                             1/1     Running     0          10m
kube-system                    nodelocaldns-22ccz                                   1/1     Running     0          10m
kube-system                    nodelocaldns-4ghrt                                   1/1     Running     0          10m
kube-system                    nodelocaldns-5xdgx                                   1/1     Running     0          10m
kube-system                    nodelocaldns-6k6fc                                   1/1     Running     0          10m
kube-system                    nodelocaldns-bf455                                   1/1     Running     0          10m
kube-system                    nodelocaldns-cjp4k                                   1/1     Running     0          10m

最后再随便找个域名测试下

[root@master1 ~]# yum provides nslookup
[root@master1 ~]# yum -y install bind-utils
[root@master1 ~]# nslookup node1 -n ` kubectl get svc -A|grep dns|awk '{print $4}'`
*** Invalid option: n
Server:		10.233.0.3
Address:	10.233.0.3#53

Name:	node1
Address: 10.0.1.209