coredns Pod具有CrashLoopBackOff或Error状态

  • Z时代
  • 2024-01-10
  • 分类：问答

我正在尝试通过发出以下命令来设置Kubernetes主机：

kubeadm初始化–pod-network-cidr = 192.168.0.0 / 16

  1. 随后：安装Pod Network附加组件（Calico）

  2. 跟：主隔离

问题：coredns豆荚有CrashLoopBackOff或Error状态：

# kubectl get pods -n kube-system
NAME                                       READY   STATUS             RESTARTS   AGE
calico-node-lflwx                          2/2     Running            0          2d
coredns-576cbf47c7-nm7gc                   0/1     CrashLoopBackOff   69         2d
coredns-576cbf47c7-nwcnx                   0/1     CrashLoopBackOff   69         2d
etcd-suey.nknwn.local                      1/1     Running            0          2d
kube-apiserver-suey.nknwn.local            1/1     Running            0          2d
kube-controller-manager-suey.nknwn.local   1/1     Running            0          2d
kube-proxy-xkgdr                           1/1     Running            0          2d
kube-scheduler-suey.nknwn.local            1/1     Running            0          2d
#

我尝试对kubeadm-

Kubernetes进行故障排除，但是我的节点未运行，SELinux并且Docker是最新的。

# docker --version
Docker version 18.06.1-ce, build e68fc7a
#

kubectl的describe：

# kubectl -n kube-system describe pod coredns-576cbf47c7-nwcnx 
Name:               coredns-576cbf47c7-nwcnx
Namespace:          kube-system
Priority:           0
PriorityClassName:  <none>
Node:               suey.nknwn.local/192.168.86.81
Start Time:         Sun, 28 Oct 2018 22:39:46 -0400
Labels:             k8s-app=kube-dns
                    pod-template-hash=576cbf47c7
Annotations:        cni.projectcalico.org/podIP: 192.168.0.30/32
Status:             Running
IP:                 192.168.0.30
Controlled By:      ReplicaSet/coredns-576cbf47c7
Containers:
  coredns:
    Container ID:  docker://ec65b8f40c38987961e9ed099dfa2e8bb35699a7f370a2cda0e0d522a0b05e79
    Image:         k8s.gcr.io/coredns:1.2.2
    Image ID:      docker-pullable://k8s.gcr.io/coredns@sha256:3e2be1cec87aca0b74b7668bbe8c02964a95a402e45ceb51b2252629d608d03a
    Ports:         53/UDP, 53/TCP, 9153/TCP
    Host Ports:    0/UDP, 0/TCP, 0/TCP
    Args:
      -conf
      /etc/coredns/Corefile
    State:          Running
      Started:      Wed, 31 Oct 2018 23:28:58 -0400
    Last State:     Terminated
      Reason:       Error
      Exit Code:    137
      Started:      Wed, 31 Oct 2018 23:21:35 -0400
      Finished:     Wed, 31 Oct 2018 23:23:54 -0400
    Ready:          True
    Restart Count:  103
    Limits:
      memory:  170Mi
    Requests:
      cpu:        100m
      memory:     70Mi
    Liveness:     http-get http://:8080/health delay=60s timeout=5s period=10s #success=1 #failure=5
    Environment:  <none>
    Mounts:
      /etc/coredns from config-volume (ro)
      /var/run/secrets/kubernetes.io/serviceaccount from coredns-token-xvq8b (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  config-volume:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      coredns
    Optional:  false
  coredns-token-xvq8b:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  coredns-token-xvq8b
    Optional:    false
QoS Class:       Burstable
Node-Selectors:  <none>
Tolerations:     CriticalAddonsOnly
                 node-role.kubernetes.io/master:NoSchedule
                 node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason     Age                     From                       Message
  ----     ------     ----                    ----                       -------
  Normal   Killing    54m (x10 over 4h19m)    kubelet, suey.nknwn.local  Killing container with id docker://coredns:Container failed liveness probe.. Container will be killed and recreated.
  Warning  Unhealthy  9m56s (x92 over 4h20m)  kubelet, suey.nknwn.local  Liveness probe failed: HTTP probe failed with statuscode: 503
  Warning  BackOff    5m4s (x173 over 4h10m)  kubelet, suey.nknwn.local  Back-off restarting failed container
# kubectl -n kube-system describe pod coredns-576cbf47c7-nm7gc 
Name:               coredns-576cbf47c7-nm7gc
Namespace:          kube-system
Priority:           0
PriorityClassName:  <none>
Node:               suey.nknwn.local/192.168.86.81
Start Time:         Sun, 28 Oct 2018 22:39:46 -0400
Labels:             k8s-app=kube-dns
                    pod-template-hash=576cbf47c7
Annotations:        cni.projectcalico.org/podIP: 192.168.0.31/32
Status:             Running
IP:                 192.168.0.31
Controlled By:      ReplicaSet/coredns-576cbf47c7
Containers:
  coredns:
    Container ID:  docker://0f2db8d89a4c439763e7293698d6a027a109bf556b806d232093300952a84359
    Image:         k8s.gcr.io/coredns:1.2.2
    Image ID:      docker-pullable://k8s.gcr.io/coredns@sha256:3e2be1cec87aca0b74b7668bbe8c02964a95a402e45ceb51b2252629d608d03a
    Ports:         53/UDP, 53/TCP, 9153/TCP
    Host Ports:    0/UDP, 0/TCP, 0/TCP
    Args:
      -conf
      /etc/coredns/Corefile
    State:          Running
      Started:      Wed, 31 Oct 2018 23:29:11 -0400
    Last State:     Terminated
      Reason:       Error
      Exit Code:    137
      Started:      Wed, 31 Oct 2018 23:21:58 -0400
      Finished:     Wed, 31 Oct 2018 23:24:08 -0400
    Ready:          True
    Restart Count:  102
    Limits:
      memory:  170Mi
    Requests:
      cpu:        100m
      memory:     70Mi
    Liveness:     http-get http://:8080/health delay=60s timeout=5s period=10s #success=1 #failure=5
    Environment:  <none>
    Mounts:
      /etc/coredns from config-volume (ro)
      /var/run/secrets/kubernetes.io/serviceaccount from coredns-token-xvq8b (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  config-volume:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      coredns
    Optional:  false
  coredns-token-xvq8b:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  coredns-token-xvq8b
    Optional:    false
QoS Class:       Burstable
Node-Selectors:  <none>
Tolerations:     CriticalAddonsOnly
                 node-role.kubernetes.io/master:NoSchedule
                 node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason     Age                     From                       Message
  ----     ------     ----                    ----                       -------
  Normal   Killing    44m (x12 over 4h18m)    kubelet, suey.nknwn.local  Killing container with id docker://coredns:Container failed liveness probe.. Container will be killed and recreated.
  Warning  BackOff    4m58s (x170 over 4h9m)  kubelet, suey.nknwn.local  Back-off restarting failed container
  Warning  Unhealthy  8s (x102 over 4h19m)    kubelet, suey.nknwn.local  Liveness probe failed: HTTP probe failed with statuscode: 503
#

kubectl的log：

# kubectl -n kube-system logs -f coredns-576cbf47c7-nm7gc 
E1101 03:31:58.974836       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:348: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:31:58.974836       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:355: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:31:58.974857       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:350: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:32:29.975493       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:348: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:32:29.976732       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:355: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:32:29.977788       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:350: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:33:00.976164       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:348: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:33:00.977415       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:355: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:33:00.978332       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:350: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
2018/11/01 03:33:08 [INFO] SIGTERM: Shutting down servers then terminating
E1101 03:33:31.976864       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:348: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:33:31.978080       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:355: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1101 03:33:31.979156       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:350: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
#
# kubectl -n kube-system log -f coredns-576cbf47c7-gqdgd
.:53
2018/11/05 04:04:13 [INFO] CoreDNS-1.2.2
2018/11/05 04:04:13 [INFO] linux/amd64, go1.11, eb51e8b
CoreDNS-1.2.2
linux/amd64, go1.11, eb51e8b
2018/11/05 04:04:13 [INFO] plugin/reload: Running configuration MD5 = f65c4821c8a9b7b5eb30fa4fbc167769
2018/11/05 04:04:19 [FATAL] plugin/loop: Seen "HINFO IN 3597544515206064936.6415437575707023337." more than twice, loop detected
# kubectl -n kube-system log -f coredns-576cbf47c7-hhmws
.:53
2018/11/05 04:04:18 [INFO] CoreDNS-1.2.2
2018/11/05 04:04:18 [INFO] linux/amd64, go1.11, eb51e8b
CoreDNS-1.2.2
linux/amd64, go1.11, eb51e8b
2018/11/05 04:04:18 [INFO] plugin/reload: Running configuration MD5 = f65c4821c8a9b7b5eb30fa4fbc167769
2018/11/05 04:04:24 [FATAL] plugin/loop: Seen "HINFO IN 6900627972087569316.7905576541070882081." more than twice, loop detected
#

describe（apiserver）：

# kubectl -n kube-system describe pod kube-apiserver-suey.nknwn.local
Name:               kube-apiserver-suey.nknwn.local
Namespace:          kube-system
Priority:           2000000000
PriorityClassName:  system-cluster-critical
Node:               suey.nknwn.local/192.168.87.20
Start Time:         Fri, 02 Nov 2018 00:28:44 -0400
Labels:             component=kube-apiserver
                    tier=control-plane
Annotations:        kubernetes.io/config.hash: 2433a531afe72165364aace3b746ea4c
                    kubernetes.io/config.mirror: 2433a531afe72165364aace3b746ea4c
                    kubernetes.io/config.seen: 2018-11-02T00:28:43.795663261-04:00
                    kubernetes.io/config.source: file
                    scheduler.alpha.kubernetes.io/critical-pod: 
Status:             Running
IP:                 192.168.87.20
Containers:
  kube-apiserver:
    Container ID:  docker://659456385a1a859f078d36f4d1b91db9143d228b3bc5b3947a09460a39ce41fc
    Image:         k8s.gcr.io/kube-apiserver:v1.12.2
    Image ID:      docker-pullable://k8s.gcr.io/kube-apiserver@sha256:094929baf3a7681945d83a7654b3248e586b20506e28526121f50eb359cee44f
    Port:          <none>
    Host Port:     <none>
    Command:
      kube-apiserver
      --authorization-mode=Node,RBAC
      --advertise-address=192.168.87.20
      --allow-privileged=true
      --client-ca-file=/etc/kubernetes/pki/ca.crt
      --enable-admission-plugins=NodeRestriction
      --enable-bootstrap-token-auth=true
      --etcd-cafile=/etc/kubernetes/pki/etcd/ca.crt
      --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt
      --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key
      --etcd-servers=https://127.0.0.1:2379
      --insecure-port=0
      --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt
      --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key
      --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
      --proxy-client-cert-file=/etc/kubernetes/pki/front-proxy-client.crt
      --proxy-client-key-file=/etc/kubernetes/pki/front-proxy-client.key
      --requestheader-allowed-names=front-proxy-client
      --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
      --requestheader-extra-headers-prefix=X-Remote-Extra-
      --requestheader-group-headers=X-Remote-Group
      --requestheader-username-headers=X-Remote-User
      --secure-port=6443
      --service-account-key-file=/etc/kubernetes/pki/sa.pub
      --service-cluster-ip-range=10.96.0.0/12
      --tls-cert-file=/etc/kubernetes/pki/apiserver.crt
      --tls-private-key-file=/etc/kubernetes/pki/apiserver.key
    State:          Running
      Started:      Sun, 04 Nov 2018 22:57:27 -0500
    Last State:     Terminated
      Reason:       Completed
      Exit Code:    0
      Started:      Sun, 04 Nov 2018 20:12:06 -0500
      Finished:     Sun, 04 Nov 2018 22:55:24 -0500
    Ready:          True
    Restart Count:  2
    Requests:
      cpu:        250m
    Liveness:     http-get https://192.168.87.20:6443/healthz delay=15s timeout=15s period=10s #success=1 #failure=8
    Environment:  <none>
    Mounts:
      /etc/ca-certificates from etc-ca-certificates (ro)
      /etc/kubernetes/pki from k8s-certs (ro)
      /etc/ssl/certs from ca-certs (ro)
      /usr/local/share/ca-certificates from usr-local-share-ca-certificates (ro)
      /usr/share/ca-certificates from usr-share-ca-certificates (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  etc-ca-certificates:
    Type:          HostPath (bare host directory volume)
    Path:          /etc/ca-certificates
    HostPathType:  DirectoryOrCreate
  k8s-certs:
    Type:          HostPath (bare host directory volume)
    Path:          /etc/kubernetes/pki
    HostPathType:  DirectoryOrCreate
  ca-certs:
    Type:          HostPath (bare host directory volume)
    Path:          /etc/ssl/certs
    HostPathType:  DirectoryOrCreate
  usr-share-ca-certificates:
    Type:          HostPath (bare host directory volume)
    Path:          /usr/share/ca-certificates
    HostPathType:  DirectoryOrCreate
  usr-local-share-ca-certificates:
    Type:          HostPath (bare host directory volume)
    Path:          /usr/local/share/ca-certificates
    HostPathType:  DirectoryOrCreate
QoS Class:         Burstable
Node-Selectors:    <none>
Tolerations:       :NoExecute
Events:            <none>
#

syslog（主机）：

11月4日22:59:36 suey kubelet [1234]：E1104 22：59：36.139538 1234

pod_workers.go：186]同步pod d8146b7e-de57-11e8-a1e2-ec8eb57434c8（“

coredns-576cbf47c7-hhmws_kube-system（d8146b7e

de57-11e8-a1e2-ec8eb57434c8）“），跳过：使用CrashLoopBackOff无法为“ coredns”启动到“

StartContainer”：“退回40s重新启动失败的容器= coredns pod =

coredns-576cbf47c7-hhmws_kube-system（d8146b7e-de57-11e8 -a1e2-ec8eb57434c8）”

请指教。

回答：

这个错误

[FATAL] plugin/loop: Seen "HINFO IN 6900627972087569316.7905576541070882081." more than twice, loop detected

是当CoreDNS在解析配置中检测到循环时引起的，这是预期的行为。您遇到了以下问题：

https://github.com/kubernetes/kubeadm/issues/1162

https://github.com/coredns/coredns/issues/2087

编辑CoreDNS配置图：

kubectl -n kube-system edit configmap coredns

使用删除或注释掉该行loop，然后保存并退出。

然后删除CoreDNS Pod，以便可以使用新的配置创建新的Pod：

kubectl -n kube-system delete pod -l k8s-app=kube-dns

在那之后一切都会好起来的。

首先，检查您是否正在使用systemd-resolved。如果您正在运行Ubuntu 18.04，则可能是这种情况。

systemctl list-unit-files | grep enabled | grep systemd-resolved

如果是，请检查resolv.conf集群使用哪个文件作为参考：

ps auxww | grep kubelet

您可能会看到类似以下的行：

/usr/bin/kubelet ... --resolv-conf=/run/systemd/resolve/resolv.conf

重要的部分是--resolv-conf-我们确定是否使用了systemd resolv.conf。

检查的内容/run/systemd/resolve/resolv.conf以查看是否有类似的记录：

nameserver 127.0.0.1

如果存在127.0.0.1，则它是导致循环的原因。

要摆脱它，您不应编辑该文件，而应检查其他位置以使其正确生成。

检查下的所有文件，/etc/systemd/network以及是否找到类似的记录

DNS=127.0.0.1

删除该记录。还要检查/etc/systemd/resolved.conf并根据需要执行相同的操作。确保至少配置了一台或两台DNS服务器，例如

DNS=1.1.1.1 1.0.0.1

完成所有这些之后，重新启动systemd服务以使更改生效：systemctl restart systemd-networkd systemd-

resolved

之后，确认文件中DNS=127.0.0.1不再存在该resolv.conf文件：

cat /run/systemd/resolve/resolv.conf

最后，触发DNS容器的重新创建

kubectl -n kube-system delete pod -l k8s-app=kube-dns

解决方案涉及从主机DNS配置中消除看起来像DNS查找循环的内容。不同的resolv.conf管理器/实现之间的步骤有所不同。

以上是 coredns Pod具有CrashLoopBackOff或Error状态 的全部内容， 来源链接： utcz.com/qa/429604.html

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