kubedns container cannot connect to apiserver #193

phagunbaya · 2017-03-03T20:21:50Z

kubedns logs:

I0303 20:17:56.595813       1 dns.go:42] version: v1.6.0-alpha.0.680+3872cb93abf948-dirty
I0303 20:17:56.596373       1 server.go:107] Using https://10.96.0.1:443 for kubernetes master, kubernetes API: <nil>
I0303 20:17:56.596882       1 server.go:68] Using configuration read from ConfigMap: kube-system:kube-dns
I0303 20:17:56.596925       1 server.go:113] FLAG: --alsologtostderr="false"
I0303 20:17:56.596943       1 server.go:113] FLAG: --config-map="kube-dns"
I0303 20:17:56.596949       1 server.go:113] FLAG: --config-map-namespace="kube-system"
I0303 20:17:56.596952       1 server.go:113] FLAG: --dns-bind-address="0.0.0.0"
I0303 20:17:56.596956       1 server.go:113] FLAG: --dns-port="10053"
I0303 20:17:56.596961       1 server.go:113] FLAG: --domain="cluster.local."
I0303 20:17:56.596967       1 server.go:113] FLAG: --federations=""
I0303 20:17:56.596971       1 server.go:113] FLAG: --healthz-port="8081"
I0303 20:17:56.596976       1 server.go:113] FLAG: --kube-master-url=""
I0303 20:17:56.596981       1 server.go:113] FLAG: --kubecfg-file=""
I0303 20:17:56.596985       1 server.go:113] FLAG: --log-backtrace-at=":0"
I0303 20:17:56.596992       1 server.go:113] FLAG: --log-dir=""
I0303 20:17:56.596996       1 server.go:113] FLAG: --log-flush-frequency="5s"
I0303 20:17:56.597001       1 server.go:113] FLAG: --logtostderr="true"
I0303 20:17:56.597005       1 server.go:113] FLAG: --stderrthreshold="2"
I0303 20:17:56.597009       1 server.go:113] FLAG: --v="2"
I0303 20:17:56.597014       1 server.go:113] FLAG: --version="false"
I0303 20:17:56.597019       1 server.go:113] FLAG: --vmodule=""
I0303 20:17:56.597113       1 server.go:155] Starting SkyDNS server (0.0.0.0:10053)
I0303 20:17:56.597414       1 server.go:165] Skydns metrics enabled (/metrics:10055)
I0303 20:17:56.597437       1 dns.go:144] Starting endpointsController
I0303 20:17:56.597443       1 dns.go:147] Starting serviceController
I0303 20:17:56.597531       1 logs.go:41] skydns: ready for queries on cluster.local. for tcp://0.0.0.0:10053 [rcache 0]
I0303 20:17:56.597554       1 logs.go:41] skydns: ready for queries on cluster.local. for udp://0.0.0.0:10053 [rcache 0]
E0303 20:17:57.601223       1 sync.go:105] Error getting ConfigMap kube-system:kube-dns err: Get https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/kube-dns: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:17:57.601271       1 dns.go:190] Error getting initial ConfigMap: Get https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/kube-dns: dial tcp 10.96.0.1:443: getsockopt: no route to host, starting with default values
I0303 20:17:57.601317       1 dns.go:163] Waiting for Kubernetes service
I0303 20:17:57.601331       1 dns.go:169] Waiting for service: default/kubernetes
E0303 20:17:59.605100       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:01.607159       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:04.617151       1 reflector.go:199] pkg/dns/config/sync.go:114: Failed to list *api.ConfigMap: Get https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps?fieldSelector=metadata.name%3Dkube-dns&resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:05.613089       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:07.617099       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:09.619173       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:11.621183       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:15.629124       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:17.633140       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:19.635211       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:21.637134       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:25.645156       1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: getsockopt: no route to host
E0303 20:18:26.598781       1 reflector.go:199] pkg/dns/dns.go:145: Failed to list *api.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout

kube-apiserver logs

I0303 20:02:55.656265       1 config.go:527] Will report 10.160.20.150 as public IP address.
E0303 20:02:55.658840       1 reflector.go:199] k8s.io/kubernetes/plugin/pkg/admission/serviceaccount/admission.go:103: Failed to list *api.ServiceAccount: Get http://127.0.0.1:8080/api/v1/serviceaccounts?resourceVersion=0: dial tcp 127.0.0.1:8080: getsockopt: connection refused
E0303 20:02:55.661056       1 reflector.go:199] k8s.io/kubernetes/plugin/pkg/admission/serviceaccount/admission.go:119: Failed to list *api.Secret: Get http://127.0.0.1:8080/api/v1/secrets?fieldSelector=type%3Dkubernetes.io%2Fservice-account-token&resourceVersion=0: dial tcp 127.0.0.1:8080: getsockopt: connection refused
E0303 20:02:55.661974       1 reflector.go:199] k8s.io/kubernetes/plugin/pkg/admission/storageclass/default/admission.go:75: Failed to list *storage.StorageClass: Get http://127.0.0.1:8080/apis/storage.k8s.io/v1beta1/storageclasses?resourceVersion=0: dial tcp 127.0.0.1:8080: getsockopt: connection refused
E0303 20:02:55.662031       1 reflector.go:199] k8s.io/kubernetes/plugin/pkg/admission/resourcequota/resource_access.go:83: Failed to list *api.ResourceQuota: Get http://127.0.0.1:8080/api/v1/resourcequotas?resourceVersion=0: dial tcp 127.0.0.1:8080: getsockopt: connection refused
E0303 20:02:55.709032       1 reflector.go:199] pkg/controller/informers/factory.go:89: Failed to list *api.LimitRange: Get http://127.0.0.1:8080/api/v1/limitranges?resourceVersion=0: dial tcp 127.0.0.1:8080: getsockopt: connection refused
E0303 20:02:55.709152       1 reflector.go:199] pkg/controller/informers/factory.go:89: Failed to list *api.Namespace: Get http://127.0.0.1:8080/api/v1/namespaces?resourceVersion=0: dial tcp 127.0.0.1:8080: getsockopt: connection refused
[restful] 2017/03/03 20:02:55 log.go:30: [restful/swagger] listing is available at https://10.160.20.150:6443/swaggerapi/
[restful] 2017/03/03 20:02:55 log.go:30: [restful/swagger] https://10.160.20.150:6443/swaggerui/ is mapped to folder /swagger-ui/
I0303 20:02:55.771165       1 serve.go:88] Serving securely on 0.0.0.0:6443
I0303 20:02:55.771302       1 serve.go:102] Serving insecurely on 127.0.0.1:8080
I0303 20:02:56.730792       1 trace.go:61] Trace "Update /api/v1/namespaces/kube-system/pods/kube-apiserver-wyml01/status" (started 2017-03-03 20:02:55.825739356 +0000 UTC):
[63.968µs] [63.968µs] About to convert to expected version
[275.186µs] [211.218µs] Conversion done
[283.347µs] [8.161µs] About to store object in database
[904.938318ms] [904.654971ms] Object stored in database
[904.9425ms] [4.182µs] Self-link added
[905.006032ms] [63.532µs] END

phagunbaya · 2017-03-03T20:24:43Z

iptables

[root@wyml01 Falkonry-k8-installer]# iptables-save 
# Generated by iptables-save v1.4.21 on Fri Mar  3 13:23:40 2017
*nat
:PREROUTING ACCEPT [2:156]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:KUBE-MARK-DROP - [0:0]
:KUBE-MARK-MASQ - [0:0]
:KUBE-NODEPORTS - [0:0]
:KUBE-POSTROUTING - [0:0]
:KUBE-SEP-SAGRE6MUSU7ISKH2 - [0:0]
:KUBE-SERVICES - [0:0]
:KUBE-SVC-ERIFXISQEP7F7OF4 - [0:0]
:KUBE-SVC-NPX46M4PTMTKRN6Y - [0:0]
:KUBE-SVC-TCOU7JCQXEZGVUNU - [0:0]
-A PREROUTING -m comment --comment "kubernetes service portals" -j KUBE-SERVICES
-A OUTPUT -m comment --comment "kubernetes service portals" -j KUBE-SERVICES
-A POSTROUTING -m comment --comment "kubernetes postrouting rules" -j KUBE-POSTROUTING
-A KUBE-MARK-DROP -j MARK --set-xmark 0x8000/0x8000
-A KUBE-MARK-MASQ -j MARK --set-xmark 0x4000/0x4000
-A KUBE-POSTROUTING -m comment --comment "kubernetes service traffic requiring SNAT" -m mark --mark 0x4000/0x4000 -j MASQUERADE
-A KUBE-SEP-SAGRE6MUSU7ISKH2 -s 10.160.20.150/32 -m comment --comment "default/kubernetes:https" -j KUBE-MARK-MASQ
-A KUBE-SEP-SAGRE6MUSU7ISKH2 -p tcp -m comment --comment "default/kubernetes:https" -m recent --set --name KUBE-SEP-SAGRE6MUSU7ISKH2 --mask 255.255.255.255 --rsource -m tcp -j DNAT --to-destination 10.160.20.150:6443
-A KUBE-SERVICES -d 10.96.0.10/32 -p udp -m comment --comment "kube-system/kube-dns:dns cluster IP" -m udp --dport 53 -j KUBE-SVC-TCOU7JCQXEZGVUNU
-A KUBE-SERVICES -d 10.96.0.10/32 -p tcp -m comment --comment "kube-system/kube-dns:dns-tcp cluster IP" -m tcp --dport 53 -j KUBE-SVC-ERIFXISQEP7F7OF4
-A KUBE-SERVICES -d 10.96.0.1/32 -p tcp -m comment --comment "default/kubernetes:https cluster IP" -m tcp --dport 443 -j KUBE-SVC-NPX46M4PTMTKRN6Y
-A KUBE-SERVICES -m comment --comment "kubernetes service nodeports; NOTE: this must be the last rule in this chain" -m addrtype --dst-type LOCAL -j KUBE-NODEPORTS
-A KUBE-SVC-NPX46M4PTMTKRN6Y -m comment --comment "default/kubernetes:https" -m recent --rcheck --seconds 10800 --reap --name KUBE-SEP-SAGRE6MUSU7ISKH2 --mask 255.255.255.255 --rsource -j KUBE-SEP-SAGRE6MUSU7ISKH2
-A KUBE-SVC-NPX46M4PTMTKRN6Y -m comment --comment "default/kubernetes:https" -j KUBE-SEP-SAGRE6MUSU7ISKH2
COMMIT
# Completed on Fri Mar  3 13:23:40 2017
# Generated by iptables-save v1.4.21 on Fri Mar  3 13:23:40 2017
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [8:452]
:KUBE-FIREWALL - [0:0]
:KUBE-SERVICES - [0:0]
:WEAVE-NPC - [0:0]
:WEAVE-NPC-DEFAULT - [0:0]
:WEAVE-NPC-INGRESS - [0:0]
-A INPUT -j KUBE-FIREWALL
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
-A OUTPUT -m comment --comment "kubernetes service portals" -j KUBE-SERVICES
-A OUTPUT -j KUBE-FIREWALL
-A KUBE-FIREWALL -m comment --comment "kubernetes firewall for dropping marked packets" -m mark --mark 0x8000/0x8000 -j DROP
-A KUBE-SERVICES -d 10.96.0.10/32 -p udp -m comment --comment "kube-system/kube-dns:dns has no endpoints" -m udp --dport 53 -j REJECT --reject-with icmp-port-unreachable
-A KUBE-SERVICES -d 10.96.0.10/32 -p tcp -m comment --comment "kube-system/kube-dns:dns-tcp has no endpoints" -m tcp --dport 53 -j REJECT --reject-with icmp-port-unreachable
-A WEAVE-NPC -m state --state RELATED,ESTABLISHED -j ACCEPT
-A WEAVE-NPC -d 224.0.0.0/4 -j ACCEPT
-A WEAVE-NPC -m state --state NEW -j WEAVE-NPC-DEFAULT
-A WEAVE-NPC -m state --state NEW -j WEAVE-NPC-INGRESS
-A WEAVE-NPC-DEFAULT -m set --match-set weave-k?Z;25^M}|1s7P3|H9i;*;MhG dst -j ACCEPT
-A WEAVE-NPC-DEFAULT -m set --match-set weave-iuZcey(5DeXbzgRFs8Szo]<@p dst -j ACCEPT
COMMIT
# Completed on Fri Mar  3 13:23:40 2017

pipejakob · 2017-03-07T02:06:28Z

I suspect you're hitting issue #196. You can verify that this is the root cause by manually editing /etc/kubernetes/manifests/kube-apiserver.yaml on the master and changing the liveness probe:

livenessProbe:
  failureThreshold: 8
  httpGet:
    host: 127.0.0.1
    path: /healthz
    port: 443           # was 6443
    scheme: HTTPS

pipejakob · 2017-03-07T02:08:54Z

@phagunbaya If you do try the above, I would also kill/restart kubelet for it to take effect faster. When I hit this problem myself, kubelet's exponential backoff was making it take forever to try to restart the kube-apiserver pod.

msavlani · 2017-03-08T02:58:56Z

Did you try flushing your iptable rules and restart kubelet service ?

phagunbaya · 2017-03-08T03:01:40Z

@msavlani Flushing iptable rules did not help.
@pipejakob Thanks ! that resolved.

errordeveloper · 2017-04-12T17:02:37Z

Also killing DNS pod seems to resolve this for me...

errordeveloper · 2017-04-12T17:05:47Z

I am not entierly sure this has to do with #196, I think there is a race condition elsewhere. I've just hit this in something I'm working on at the moment, I will update if I figure out what causes it, as seem to have a way of reproducing is reliably.

TracyBin · 2017-04-14T09:23:22Z

I setup a single-machine Kubernetes cluster for development and faced the same problem.But modifying the port does not solve the problem

jeffchanjunwei · 2017-04-25T02:28:39Z

Hi @TracyBin, how do you solve this problem at last?

TracyBin · 2017-04-25T02:32:07Z

@jeffchanjunwei It is the problem of iptables.Please try the blow command

iptables -P FORWARD ACCEPT

If the command solve your problem,please tell me.

jeffchanjunwei · 2017-04-25T02:52:16Z

@TracyBin It doesn't work. kubedns-amd64:1.9 images still can not start. Errors as follows:

kubectl describe pod kubedns
<invalid> <invalid> 1 {kubelet k8sminion1} spec.containers{kubedns} Warning Unhealthy Readiness probe failed: Get http://10.233.124.95:8081/readiness: dial tcp 10.233.124.95:8081: getsockopt: connection refused

docker logs kubedns-amd
E0425 02:28:03.129272 1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.233.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.233.0.1:443: i/o timeout
E0425 02:28:03.234570 1 reflector.go:199] pkg/dns/dns.go:145: Failed to list *api.Endpoints: Get https://10.233.0.1:443/api/v1/endpoints?resourceVersion=0: dial tcp 10.233.0.1:443: i/o timeout

pineking · 2017-05-12T11:24:31Z

@jeffchanjunwei do you solve this problem?

jeffchanjunwei · 2017-05-15T02:16:16Z

@pineking yes. It is the cause of network that results into the problem.

frankruizhi · 2017-05-16T08:30:00Z

I got the same issue,my kubedns log :

[root@k8s ~]# I0516 07:38:31.041503 I0516 07:38:31.042564 I0516 07:38:31.043625 I0516 07:38:31.043729 I0516 07:38:31.043762 I0516 07:38:31.043773 I0516 07:38:31.043780 I0516 07:38:31.043786 I0516 07:38:31.043810 I0516 07:38:31.043821 I0516 07:38:31.043829 I0516 07:38:31.043837 I0516 07:38:31.043847 I0516 07:38:31.043853 I0516 07:38:31.043863 I0516 07:38:31.043870 I0516 07:38:31.043880 I0516 07:38:31.043887 I0516 07:38:31.043901 I0516 07:38:31.043908 I0516 07:38:31.043918 I0516 07:38:31.044094 I0516 07:38:31.048954 I0516 07:38:31.048987 I0516 07:38:31.048997 I0516 07:38:31.049354 I0516 07:38:31.049383 E0516 07:39:01.051248 E0516 07:39:01.051307 I0516 07:39:01.051338 I0516 07:39:01.051347 E0516 07:39:02.228560 E0516 07:39:02.228646 E0516 07:39:32.229250 kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name) -c kubedns
1 dns.go:42] version: v1.6.0-alpha.0.680+3872cb93abf948-dirty
1 server.go:107] Using https://10.254.0.1:443 for kubernetes master, kubernetes API:
1 server.go:68] Using configuration read from ConfigMap: kube-system:kube-dns
1 server.go:113] FLAG: --alsologtostderr="false"
1 server.go:113] FLAG: --config-map="kube-dns"
1 server.go:113] FLAG: --config-map-namespace="kube-system"
1 server.go:113] FLAG: --dns-bind-address="0.0.0.0"
1 server.go:113] FLAG: --dns-port="10053"
1 server.go:113] FLAG: --domain="cluster.local."
1 server.go:113] FLAG: --federations=""
1 server.go:113] FLAG: --healthz-port="8081"
1 server.go:113] FLAG: --kube-master-url=""
1 server.go:113] FLAG: --kubecfg-file=""
1 server.go:113] FLAG: --log-backtrace-at=":0"
1 server.go:113] FLAG: --log-dir=""
1 server.go:113] FLAG: --log-flush-frequency="5s"
1 server.go:113] FLAG: --logtostderr="true"
1 server.go:113] FLAG: --stderrthreshold="2"
1 server.go:113] FLAG: --v="2"
1 server.go:113] FLAG: --version="false"
1 server.go:113] FLAG: --vmodule=""
1 server.go:155] Starting SkyDNS server (0.0.0.0:10053)
1 server.go:165] Skydns metrics enabled (/metrics:10055)
1 dns.go:144] Starting endpointsController
1 dns.go:147] Starting serviceController
1 logs.go:41] skydns: ready for queries on cluster.local. for tcp://0.0.0.0:10053 [rcache 0]
1 logs.go:41] skydns: ready for queries on cluster.local. for udp://0.0.0.0:10053 [rcache 0]
1 sync.go:105] Error getting ConfigMap kube-system:kube-dns err: Get https://10.254.0.1:443/api/v1/namespaces/kube-system/configmaps/kube-dns: dial tcp 10.254.0.1:443: i/o timeout
1 dns.go:190] Error getting initial ConfigMap: Get https://10.254.0.1:443/api/v1/namespaces/kube-system/configmaps/kube-dns: dial tcp 10.254.0.1:443: i/o timeout, starting with default values
1 dns.go:163] Waiting for Kubernetes service
1 dns.go:169] Waiting for service: default/kubernetes
1 reflector.go:199] pkg/dns/dns.go:145: Failed to list *api.Endpoints: Get https://10.254.0.1:443/api/v1/endpoints?resourceVersion=0: dial tcp 10.254.0.1:443: i/o timeout
1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.254.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.254.0.1:443: i/o timeout
1 reflector.go:199] pkg/dns/config/sync.go:114: Failed to list *api.ConfigMap: Get https://10.254.0.1:443/api/v1/namespaces/kube-system/configmaps?fieldSelector=metadata.name%3Dkube-dns&resourceVersion=0: dial tcp 10.254.0.1:443: i/o timeout

I've tied a lot ,but none of them worked.

frankruizhi · 2017-05-19T01:39:42Z

I have found the solution to my problem:

Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"a55267932d501b9fbd6d73e5ded47d79b5763ce5", GitTreeState:"clean", BuildDate:"2017-04-14T13:36:25Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"a55267932d501b9fbd6d73e5ded47d79b5763ce5", GitTreeState:"clean", BuildDate:"2017-04-14T13:36:25Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"linux/amd64"}

1.First,we should make sure the ip-forward enabled on the linux kernel of every node.Just execute command:
sysctl net.ipv4.conf.all.forwarding = 1

2.Secondly,if your docker's version >=1.13,the default FORWARD chain policy was DROP,you should set default policy of the FORWARD chain to ACCEPT:$ sudo iptables -P FORWARD ACCEPT.

3.Then the configuration of the kube-proxy must be pass in :
--cluster-cidr=.

ps: --cluster-cidr string The CIDR range of pods in the cluster. It is used to bridge traffic coming from outside of the cluster. If not provided, no off-cluster bridging will be performed.
Refer to this:kubernetes/kubernetes#36835

luxas · 2017-05-29T14:24:24Z

Closing this as fixed with v1.6

mhsabbagh · 2017-08-14T18:07:08Z

This is still here on 1.7.3 with Ubuntu 16.04. Same exact problem. Have been trying all the possible solutions from disabling apparmor, changing the ports, making sure nothing blocks it.. It still doesn't work.

I tried it on a completely fresh droplet from DigitalOcean and it's still the same. Doesn't look like a configuration problem from my side. I just ran the commands as they are in https://medium.com/@SystemMining/setup-kubenetes-cluster-on-ubuntu-16-04-with-kubeadm-336f4061d929

pengyue · 2017-08-21T10:50:27Z

@mhsabbagh, I have the exact version as yours, 1 master, 3 nodes, the dashboard was setup on node 2 automatically when apply dashboard.yaml. and dashboard error looks like the same as others.

Using HTTP port: 8443 Using in-cluster config to connect to apiserver Using service account token for csrf signing No request provided. Skipping authorization header Error while initializing connection to Kubernetes apiserver. This most likely means that the cluster is misconfigured (e.g., it has invalid apiserver certificates or service accounts configuration) or the --apiserver-host param points to a server that does not exist. Reason: Get https://10.96.0.1:443/version: dial tcp 10.96.0.1:443: i/o timeout Refer to the troubleshooting guide for more information: https://github.com/kubernetes/dashboard/blob/master/docs/user-guide/troubleshooting.md

I have been searching for an solution, but still cannot find a solution. I could telnet to 10.96.0.1 on port 443 from any of the master and nodes

Are we sure it has been fixed in v1.6?

gogeof · 2017-08-29T07:13:29Z

I also have this problem in kubernetes v1.7.4, and after I restart docker, it fix.

BenHall · 2017-09-05T09:26:52Z

Also hitting this on a fair frequent basis with Kubernetes 1.7 on top of Docker 1.12.6

Running iptables -P FORWARD ACCEPT didn't resolve the issue.

luxas · 2017-09-05T15:05:41Z

@BenHall please open a new issue with relevant details.

lastboy1228 · 2017-09-17T16:37:48Z

systemctl stop kubelet
systemctl stop docker
iptables --flush
iptables -tnat --flush
systemctl start kubelet
systemctl start docker

The route problem can be solved by flush iptables.

P4otocol · 2017-10-13T07:12:12Z

Thanks @frankruizhi for the info. Worked for me!! (Used docker version >1.13)

WanChengHu · 2017-10-15T14:57:08Z

I got the same problem when I use kubeadm to init a k8s v1.8 cluster with one master and one node.

Client Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.0", GitCommit:"6e937839ac04a38cac63e6a7a306c5d035fe7b0a", GitTreeState:"clean", BuildDate:"2017-09-28T22:57:57Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.0", GitCommit:"6e937839ac04a38cac63e6a7a306c5d035fe7b0a", GitTreeState:"clean", BuildDate:"2017-09-28T22:46:41Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}

WanChengHu · 2017-10-15T14:57:54Z

kubectl get pod -n kube-system

NAME READY STATUS RESTARTS AGE
etcd-redis 1/1 Running 0 6h
kube-apiserver-redis 1/1 Running 0 6h
kube-controller-manager-redis 1/1 Running 0 6h
kube-dns-545bc4bfd4-zqv6j 2/3 CrashLoopBackOff 146 6h
kube-flannel-ds-8cphc 1/1 Running 0 6h
kube-flannel-ds-dqsbr 1/1 Running 7 6h
kube-proxy-fjhlf 1/1 Running 0 6h
kube-proxy-j5pwk 1/1 Running 0 6h
kube-scheduler-redis 1/1 Running 0 6h

WanChengHu · 2017-10-15T14:59:20Z

kubectl logs kube-dns-545bc4bfd4-zqv6j -n kube-system -c kubedns --previous=true
I1015 13:25:06.436183 1 dns.go:48] version: 1.14.4-2-g5584e04
I1015 13:25:06.436763 1 server.go:70] Using configuration read from directory: /kube-dns-config with period 10s
I1015 13:25:06.436807 1 server.go:113] FLAG: --alsologtostderr="false"
I1015 13:25:06.436818 1 server.go:113] FLAG: --config-dir="/kube-dns-config"
I1015 13:25:06.436824 1 server.go:113] FLAG: --config-map=""
I1015 13:25:06.436826 1 server.go:113] FLAG: --config-map-namespace="kube-system"
I1015 13:25:06.436829 1 server.go:113] FLAG: --config-period="10s"
I1015 13:25:06.436833 1 server.go:113] FLAG: --dns-bind-address="0.0.0.0"
I1015 13:25:06.436835 1 server.go:113] FLAG: --dns-port="10053"
I1015 13:25:06.436843 1 server.go:113] FLAG: --domain="cluster.local."
I1015 13:25:06.436848 1 server.go:113] FLAG: --federations=""
I1015 13:25:06.436851 1 server.go:113] FLAG: --healthz-port="8081"
I1015 13:25:06.436854 1 server.go:113] FLAG: --initial-sync-timeout="1m0s"
I1015 13:25:06.436856 1 server.go:113] FLAG: --kube-master-url=""
I1015 13:25:06.436861 1 server.go:113] FLAG: --kubecfg-file=""
I1015 13:25:06.436864 1 server.go:113] FLAG: --log-backtrace-at=":0"
I1015 13:25:06.436868 1 server.go:113] FLAG: --log-dir=""
I1015 13:25:06.436874 1 server.go:113] FLAG: --log-flush-frequency="5s"
I1015 13:25:06.436876 1 server.go:113] FLAG: --logtostderr="true"
I1015 13:25:06.436886 1 server.go:113] FLAG: --nameservers=""
I1015 13:25:06.436888 1 server.go:113] FLAG: --stderrthreshold="2"
I1015 13:25:06.436891 1 server.go:113] FLAG: --v="2"
I1015 13:25:06.436893 1 server.go:113] FLAG: --version="false"
I1015 13:25:06.436898 1 server.go:113] FLAG: --vmodule=""
I1015 13:25:06.436994 1 server.go:176] Starting SkyDNS server (0.0.0.0:10053)
I1015 13:25:06.437258 1 server.go:198] Skydns metrics enabled (/metrics:10055)
I1015 13:25:06.437275 1 dns.go:147] Starting endpointsController
I1015 13:25:06.437284 1 dns.go:150] Starting serviceController
I1015 13:25:06.437361 1 logs.go:41] skydns: ready for queries on cluster.local. for tcp://0.0.0.0:10053 [rcache 0]
I1015 13:25:06.437368 1 logs.go:41] skydns: ready for queries on cluster.local. for udp://0.0.0.0:10053 [rcache 0]
I1015 13:25:06.937453 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:07.437470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:07.937473 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:08.437480 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:08.937473 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:09.437483 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:09.937481 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:10.437460 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:10.937489 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:11.437451 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:11.937473 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:12.437473 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:12.937484 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:13.437496 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:13.937474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:14.437485 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:14.937470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:15.437470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:15.937467 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:16.437474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:16.937469 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:17.437484 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:17.937492 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:18.437474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:18.937499 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:19.437459 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:19.937495 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:20.437475 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:20.937483 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:21.437476 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:21.937459 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:22.437477 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:22.937462 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:23.437508 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:23.937452 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:24.437490 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:24.937443 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:25.437472 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:25.937494 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:26.437496 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:26.937482 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:27.437452 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:27.937494 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:28.437492 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:28.937486 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:29.437470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:29.937467 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:30.437456 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:30.937489 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:31.437469 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:31.937458 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:32.437459 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:32.937459 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:33.437468 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:33.937467 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:34.437467 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:34.937496 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:35.437477 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:35.937481 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:36.437505 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
E1015 13:25:36.437852 1 reflector.go:199] k8s.io/dns/vendor/k8s.io/client-go/tools/cache/reflector.go:94: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E1015 13:25:36.437865 1 reflector.go:199] k8s.io/dns/vendor/k8s.io/client-go/tools/cache/reflector.go:94: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
I1015 13:25:36.937466 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:37.437493 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:37.937476 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:38.437478 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:38.937487 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:39.437473 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:39.937470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:40.437487 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:40.937459 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:41.437504 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:41.937481 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:42.437470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:42.937469 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:43.437474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:43.937452 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:44.437449 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:44.937487 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:45.437460 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:45.937484 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:46.437500 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:46.937444 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:47.437488 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:47.937478 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:48.437479 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:48.937471 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:49.437485 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:49.937470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:50.437476 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:50.937475 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:51.437490 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:51.937446 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:52.437486 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:52.937470 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:53.437465 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:53.937482 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:54.437456 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:54.937469 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:55.437467 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:55.937489 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:56.437471 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:56.937464 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:57.437451 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:57.937504 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:58.437482 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:58.937474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:59.437479 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:59.937460 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:00.437505 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:00.937463 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:01.437480 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:01.937465 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:02.437468 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:02.937452 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:03.437474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:03.937474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:04.437474 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:04.937467 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:05.437473 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:26:05.937472 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...

WanChengHu · 2017-10-15T15:00:28Z

kubectl logs kube-dns-545bc4bfd4-zqv6j -n kube-system -c dnsmasq --previous=true
I1015 13:25:06.494999 1 main.go:76] opts: {{/usr/sbin/dnsmasq [-k --cache-size=1000 --log-facility=- --server=/cluster.local/127.0.0.1#10053 --server=/in-addr.arpa/127.0.0.1#10053 --server=/ip6.arpa/127.0.0.1#10053] true} /etc/k8s/dns/dnsmasq-nanny 10000000000}
I1015 13:25:06.495117 1 nanny.go:86] Starting dnsmasq [-k --cache-size=1000 --log-facility=- --server=/cluster.local/127.0.0.1#10053 --server=/in-addr.arpa/127.0.0.1#10053 --server=/ip6.arpa/127.0.0.1#10053]
I1015 13:25:06.503314 1 nanny.go:111]
I1015 13:25:06.503330 1 nanny.go:108] dnsmasq[14]: started, version 2.78-security-prerelease cachesize 1000
W1015 13:25:06.503339 1 nanny.go:112] Got EOF from stdout
I1015 13:25:06.503343 1 nanny.go:108] dnsmasq[14]: compile time options: IPv6 GNU-getopt no-DBus no-i18n no-IDN DHCP DHCPv6 no-Lua TFTP no-conntrack ipset auth no-DNSSEC loop-detect inotify
I1015 13:25:06.503348 1 nanny.go:108] dnsmasq[14]: using nameserver 127.0.0.1#10053 for domain ip6.arpa
I1015 13:25:06.503352 1 nanny.go:108] dnsmasq[14]: using nameserver 127.0.0.1#10053 for domain in-addr.arpa
I1015 13:25:06.503355 1 nanny.go:108] dnsmasq[14]: using nameserver 127.0.0.1#10053 for domain cluster.local
I1015 13:25:06.503358 1 nanny.go:108] dnsmasq[14]: reading /etc/resolv.conf
I1015 13:25:06.503361 1 nanny.go:108] dnsmasq[14]: using nameserver 127.0.0.1#10053 for domain ip6.arpa
I1015 13:25:06.503364 1 nanny.go:108] dnsmasq[14]: using nameserver 127.0.0.1#10053 for domain in-addr.arpa
I1015 13:25:06.503402 1 nanny.go:108] dnsmasq[14]: using nameserver 127.0.0.1#10053 for domain cluster.local
I1015 13:25:06.503405 1 nanny.go:108] dnsmasq[14]: using nameserver 100.100.2.138#53
I1015 13:25:06.503409 1 nanny.go:108] dnsmasq[14]: using nameserver 100.100.2.136#53
I1015 13:25:06.503412 1 nanny.go:108] dnsmasq[14]: read /etc/hosts - 7 addresses

WanChengHu · 2017-10-16T04:43:07Z

@TracyBin flannel 0.9.0, yes I use kubeadm
@frankruizhi let me try

WanChengHu · 2017-10-16T05:59:21Z

@frankruizhi doesn't work

TracyBin · 2017-10-16T06:15:53Z

@WanChengHu Does pod bind with ip? Most of reason is iptables and flannel network.

systemctl disable firewalld;systemctl stop firewalld;iptables -P FORWARD ACCEPT

zxpower · 2017-10-16T13:24:41Z

I have exactly the same problem - had it on K8s v1.8.0 and today I upgrade to v1.8.1 - still the same.

OS: CoreOS 1465.8.0 (with included Docker 1.12.6)
K8s: v1.8.1
Etcd: 3.0.17
Flannel: 0.7.1

WanChengHu · 2017-10-19T01:07:16Z

@TracyBin my k8s cluster is installed in Aliyun, and they tell me that they don't support k8s 1.8
the firewalld is disabled, iptables allow all inboud and outboud traffic

TracyBin · 2017-10-19T03:29:08Z

@WanChengHu 加我QQ看一下 641555100

dl00 · 2017-10-20T08:19:22Z

I am also having this problem. Spent over 2 hours on gitter trying to resolve it with someone. No luck.

luxas · 2017-10-20T10:24:41Z

@dl00 and others, if you do think you've found an issue, please open a new issue with actual details from your environment. Please don't comment on closed ones.

ikus060 · 2017-11-10T18:45:01Z

Running iptables -P FORWARD ACCEPT on master and nodes solved the problem for me.
I was running flannel.

kwaazaar · 2018-02-04T13:40:38Z

Which pod network is preferred/works out of the box? I'm running into these same issues, but I have no clue how to fix them. I picked kube-router btw, but running into these same issues.

errordeveloper · 2018-02-13T18:57:27Z

Robert, I don't know how mature kube-router is, have you tried Weave Net?

…

On Sun, 4 Feb 2018, 1:40 pm Robert te Kaat, ***@***.***> wrote: Which pod network is preferred/works out of the box? I'm running into these same issues, but I have no clue how to fix them. I picked kube-router btw, but running into these same issues. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#193 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAPWS9zoKgV8dj6-lL_dyKmmfxlrw4Mqks5tRbNWgaJpZM4MStGG> .

xiaoguazh · 2018-06-07T14:53:39Z

I set k8s cluster using virtualbox, 1-kube-master, 2-kube-workers.

When google, there are lots of similar issue, although many ticket shows closed, I tried a lot, but no luck.
I tried "$sudo iptables -P FORWARD ACCEPT", "$ sudo iptables --flush", this doesn't work for me.

The root cause should be in kube-dns, flannel and kube-proxy, anyone can tell exactly what is wrong in them ? :-)

kube-dns has 3 components/container: kubedns, dnsmasq,sidecar

`
kube-system kube-dns-598d7bf7d4-dzbn8 2/3 CrashLoopBackOff 43 10h
kube-system kube-dns-598d7bf7d4-v99tk 2/3 CrashLoopBackOff 45 10h
kube-system kube-flannel-ds-mvrt5 1/1 Running 8 20h
kube-system kube-flannel-ds-vt2w6 1/1 Running 5 20h
kube-system kube-flannel-ds-xrsq8 1/1 Running 5 20h
kube-system kube-proxy-jrw6f 1/1 Running 5 21h
kube-system kube-proxy-mt6mz 1/1 Running 8 21h
kube-system kube-proxy-wwd95 1/1 Running 5 21h

`

try use kubectl exec to check each container

(1) kubedns = always down with error in log.

` Waiting for services and endpoints to be initialized from apiserver...

reflector.go:201] k8s.io/dns/pkg/dns/dns.go:147: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout

reflector.go:201] k8s.io/dns/pkg/dns/dns.go:150: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout

dns.go:173] Waiting for services and endpoints to be initialized from apiserver...

`

(2) dnsmasq = ok, but it seems the default /etc/resolv.conf might have issue, why it uses my HOST machine's DNS setting? should it use "nameserver 10.96.0.10" ?

`
dnsmasq[12]: using nameserver 127.0.0.1#10053 for domain ip6.arpa
dnsmasq[12]: using nameserver 127.0.0.1#10053 for domain in-addr.arpa
dnsmasq[12]: using nameserver 127.0.0.1#10053 for domain cluster.local
dnsmasq[12]: reading /etc/resolv.conf
dnsmasq[12]: using nameserver 127.0.0.1#10053 for domain ip6.arpa
dnsmasq[12]: using nameserver 127.0.0.1#10053 for domain in-addr.arpa
dnsmasq[12]: using nameserver 127.0.0.1#10053 for domain cluster.local
dnsmasq[12]: using nameserver 10.158.54.11#53
dnsmasq[12]: using nameserver 10.158.54.12#53
dnsmasq[12]: using nameserver 10.158.57.11#53
dnsmasq[12]: read /etc/hosts - 7 addresses

/ # cat /etc/resolv.conf
nameserver 10.158.54.11
nameserver 10.158.54.12
nameserver 10.158.57.11
search nokia.com china.nsn-net.net


/ # netstat -nl
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 0.0.0.0:53              0.0.0.0:*               LISTEN
tcp        0      0 :::10053                :::*                    LISTEN
tcp        0      0 :::10054                :::*                    LISTEN
tcp        0      0 :::10055                :::*                    LISTEN
tcp        0      0 :::53                   :::*                    LISTEN
udp        0      0 0.0.0.0:53              0.0.0.0:*
udp        0      0 0.0.0.0:14494           0.0.0.0:*
udp        0      0 0.0.0.0:42680           0.0.0.0:*
udp        0      0 0.0.0.0:61748           0.0.0.0:*
udp        0      0 :::10053                :::*
udp        0      0 :::53                   :::*

`

(3)sidecar = ok, with failure on dnsProbe, this seems NOT a big issue.

`
dnsprobe.go:75] Starting dnsProbe {Label:kubedns Server:127.0.0.1:10053 Name:kubernetes.default.svc.cluster.local. Interval:5s Type:33}

dnsprobe.go:75] Starting dnsProbe {Label:dnsmasq Server:127.0.0.1:53 Name:kubernetes.default.svc.cluster.local. Interval:5s Type:33}

server.go:64] Error getting metrics from dnsmasq: read udp 127.0.0.1:45259->127.0.0.1:53: read: connection refused
server.go:64] Error getting metrics from dnsmasq: read udp 127.0.0.1:45932->127.0.0.1:53: read: connection refused


~ $ netstat -nl
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 0.0.0.0:53              0.0.0.0:*               LISTEN
tcp        0      0 :::10054                :::*                    LISTEN
tcp        0      0 :::53                   :::*                    LISTEN
udp        0      0 0.0.0.0:39749           0.0.0.0:*
udp        0      0 0.0.0.0:45937           0.0.0.0:*
udp        0      0 0.0.0.0:44462           0.0.0.0:*
udp        0      0 0.0.0.0:18938           0.0.0.0:*
udp        0      0 0.0.0.0:53              0.0.0.0:*
udp        0      0 0.0.0.0:20040           0.0.0.0:*
udp        0      0 :::53                   :::*
Active UNIX domain sockets (only servers)
Proto RefCnt Flags       Type       State         I-Node Path

`

10.96.0.1:443 is the cluster ip of kubernetes service, this service is in "default" namespace, can kube-dns from namesapce "kube-system" able to access this in namespace "default" ? I suspect here might have problem ?

`
$ kubectl describe service kubernetes

Name:              kubernetes
Namespace:         default
Labels:            component=apiserver
                   provider=kubernetes
Annotations:       <none>
Selector:          <none>
Type:              ClusterIP
IP:                10.96.0.1                            #-service-cidr 10.96.0.0/12 
Port:              https  443/TCP
TargetPort:        6443/TCP
Endpoints:         192.168.56.101:6443
Session Affinity:  ClientIP
Events:            <none>

`

BenHall · 2018-06-07T14:55:27Z

@xiangpengzhao We had an issue where it was a timing related bug with IPTables. Our solution was to upgrade to the latest CNI plugin (in our case Weave).

Nurza · 2018-08-07T15:38:48Z

Same problem here with K8S 1.10.5 and weave 2.3.0.

The problem is solved temporarily thanks to lastboy1228 (#193 (comment))

xingjinglu · 2018-10-29T06:19:46Z

@pineking yes. It is the cause of network that results into the problem.

Hi, How did you solve the problem? I encounter the same issue too.

charles820 · 2018-10-31T11:59:32Z

@pineking yes. It is the cause of network that results into the problem.

Hi, How did you solve the problem? I encounter the same issue too.

kubectl delete svc kubernetes

ChangjunZhao · 2018-11-22T15:37:15Z

For flannel network add-on to work correctly, you must pass --pod-network-cidr=10.244.0.0/16 to kubeadm init

o3o3o · 2019-02-12T07:38:18Z

systemctl stop kubelet
systemctl stop docker
iptables --flush
iptables -tnat --flush
systemctl start kubelet
systemctl start docker

The route problem can be solved by flush iptables.

You may need to execute the below command to ensure that the default policy is ACCEPT， to avoiding you are kicked out of your machine when using ssh.

iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT

And then you can safely flush your rules:

iptables -F

tnimni · 2019-02-13T11:18:53Z

if you are using rancher you can go to kubernetes>infrastructre stacks
search for kubernetes pod and restart it

vincent081 · 2019-12-04T06:57:13Z

@WanChengHu 加我QQ看一下 641555100

这个问题解决了吗?我也遇到这个问题.TKS!

go/tools/cache/reflector.go:94: Failed to list *v1.Service: Get https://10.9.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.9.0.1:443: i/o timeout
E1015 13:25:36.437865 1 reflector.go:199] k8s.io/dns/vendor/k8s.io/client-go/tools/cache/reflector.go:94: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?resourceVersion=0: dial tcp 10.9.0.1:443: i/o timeout
I1015 13:25:36.937466 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserver...
I1015 13:25:37.437493 1 dns.go:174] Waiting for services and endpoints to be initialized from apiserv

luxas closed this May 29, 2017

keslerm mentioned this issue Aug 6, 2017

Pod not starting #237

Closed

BenHall mentioned this issue Sep 17, 2017

DNS unable to communicate with API - No route to host #459

Closed

dl00 mentioned this issue Oct 20, 2017

kube-dns cannot connect to apiserver #504

Closed

This was referenced Nov 10, 2017

Kubeadm hosted install fails (kube-dns CrashLoopBackOff after 3m) help wanted projectcalico/calico#1337

Closed

Kubeadm hosted install + Calico pod networking fails (kube-dns CrashLoopBackOff after 3m) kubernetes/kubernetes#55471

Closed

debloper mentioned this issue Nov 29, 2017

feat(deploy): run integrated planner stack on minishift #2342

Closed

BobbyJohansen mentioned this issue Dec 13, 2017

Altering autscale group in AWS makes dns faulty #4050

Closed

neolit123 mentioned this issue Nov 20, 2018

coredns fails with invalid kube-api endpoint #1264

Closed

mosaicwang mentioned this issue Jan 30, 2019

helm #1093

Open

albinsuresh mentioned this issue May 27, 2019

none: coredns CrashLoopBackOff: dial tcp ip:443: connect: no route to host #4350

Open

nidhi-ag mentioned this issue Sep 24, 2019

systemctl stop kubelet #1800

Closed

eddebc mentioned this issue Dec 2, 2019

kubernetes-dashboard CrashLoopBackOff #5188

Open

kubernetes/kubeadm

Join GitHub today

kubedns container cannot connect to apiserver #193

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