les pods de Coredns ont l’état CrashLoopBackOff ou Error
J'essaie de configurer le maître Kubernetes en émettant:
kubeadm init --pod-network-cidr = 192.168.0.0/16
- suivi de: Installation d'un add-on pour réseau de pod (Calico)
- suivi de: Master Isolation
problème: les variables coredns ont le statut CrashLoopBackOff ou Error:
# 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
#
J'ai essayé avec Dépannage de kubeadm - Kubernetes , cependant mon noeud ne tourne pas SELinux et mon Docker est à jour.
# docker --version
Docker version 18.06.1-ce, build e68fc7a
#
kubectl 's 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 's 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 (hôte):
4 novembre 22:59:36 suey kubelet [1234]: E1104 22: 59: 36.139538 1234 pod_workers.go: 186] Erreur lors de la synchronisation du pod d8146b7e-de57-11e8-a1e2-ec8eb57434c8 ("coredns-576cbf47c7-hhmws_kube-system (d8146b7e-de-11-118-a1e2-ec8eb57434c8)"), sautant: échec de "StartContainer" pour "coredns" avec CrashLoopBackOff: "Retarder le redémarrage de 40 secondes container = coredns Pod = coredns-576cbf47c7-hhmws_kube-system (d8146b7e-de57-11e8-a1e2-ec8eb57434c8)"
S'il vous plaît donnez votre avis.
Cette erreur
[FATAL] plugin/loop: Seen "HINFO IN 6900627972087569316.7905576541070882081." more than twice, loop detected
est provoqué lorsque CoreDNS détecte une boucle dans la configuration de résolution et qu'il s'agit du comportement souhaité. Vous frappez ce problème:
https://github.com/kubernetes/kubeadm/issues/1162
https://github.com/coredns/coredns/issues/2087
Solution Hacky: Désactiver la détection de boucle CoreDNS
Editez le configmap CoreDNS:
kubectl -n kube-system edit configmap coredns
Supprimez ou commentez la ligne avec loop, enregistrez et quittez.
Ensuite, supprimez les pods CoreDNS pour en créer de nouveaux avec une nouvelle configuration:
kubectl -n kube-system delete pod -l k8s-app=kube-dns
Tout devrait bien se passer après.
Solution recommandée: supprimez la boucle dans la configuration DNS
Tout d’abord, vérifiez si vous utilisez systemd-resolved. Si vous utilisez Ubuntu 18.04, c'est probablement le cas.
systemctl list-unit-files | grep enabled | grep systemd-resolved
Si tel est le cas, vérifiez le fichier resolv.conf que votre cluster utilise comme référence:
ps auxww | grep kubelet
Vous pourriez voir une ligne comme:
/usr/bin/kubelet ... --resolv-conf=/run/systemd/resolve/resolv.conf
La partie importante est --resolv-conf - nous déterminons si systemd resolv.conf est utilisé ou non.
S'il s'agit du resolv.conf de systemd, procédez comme suit:
Vérifiez le contenu de /run/systemd/resolve/resolv.conf pour voir s’il existe un enregistrement du type:
nameserver 127.0.0.1
S'il existe 127.0.0.1, c'est celui qui provoque la boucle.
Pour vous en débarrasser, vous ne devez pas éditer ce fichier, mais consulter d’autres emplacements pour le générer correctement.
Vérifiez tous les fichiers sous /etc/systemd/network et si vous trouvez un enregistrement comme
DNS=127.0.0.1
supprimer cet enregistrement. Vérifiez également /etc/systemd/resolved.conf et faites la même chose si nécessaire. Assurez-vous d’avoir au moins un ou deux serveurs DNS configurés, tels que
DNS=1.1.1.1 1.0.0.1
Après avoir fait tout cela, redémarrez les services systemd pour que vos modifications prennent effet: Systemctl redémarrez systemd-networkd avec la résolution systemd
Après cela, vérifiez que DNS=127.0.0.1 ne figure plus dans le fichier resolv.conf:
cat /run/systemd/resolve/resolv.conf
Enfin, déclencher la recréation des pods DNS
kubectl -n kube-system delete pod -l k8s-app=kube-dns
Résumé: La solution consiste à supprimer de la configuration DNS de l'hôte une boucle de recherche DNS. Les étapes varient entre différents gestionnaires/implémentations de resolv.conf.
Voici quelques exemples de hackery Shell qui automatise Utku 's answer :
# remove loop from DNS config files
Sudo find /etc/systemd/network /etc/systemd/resolved.conf -type f \
-exec sed -i '/^DNS=127.0.0.1/d' {} +
# if necessary, configure some DNS servers (use cloudfare public)
if ! grep '^DNS=.*' /etc/systemd/resolved.conf; then
Sudo sed -i '$aDNS=1.1.1.1 1.0.0.1' /etc/systemd/resolved.conf
fi
# restart systemd services
Sudo systemctl restart systemd-networkd systemd-resolved
# force (re-) creation of the dns pods
kubectl -n kube-system delete pod -l k8s-app=kube-dns