Kubernetes - DNS kann nicht eingerichtet werden

Question

Nach der Installation von Kubernetes nach: https://coreos.com/kubernetes/docs/latest/getting-started.html kann ich DNS-Addon nicht einrichten.

Kubelet läuft:

● kubelet.service 
    Loaded: loaded (/etc/systemd/system/kubelet.service; enabled; vendor preset: disabled) 
    Active: active (running) since Tue 2017-07-11 08:30:18 UTC; 35min ago 
    Process: 5489 ExecStop=/usr/bin/rkt stop --uuid-file=/var/run/kubelet-pod.uuid (code=exited, status=0/SUCCESS) 
    Process: 5507 ExecStartPre=/usr/bin/rkt rm --uuid-file=/var/run/kubelet-pod.uuid (code=exited, status=0/SUCCESS) 
    Process: 5503 ExecStartPre=/usr/bin/mkdir -p /var/log/containers (code=exited, status=0/SUCCESS) 
    Process: 5501 ExecStartPre=/usr/bin/mkdir -p /etc/kubernetes/manifests (code=exited, status=0/SUCCESS) 
Main PID: 5519 (kubelet) 
    Tasks: 21 (limit: 32768) 
    Memory: 67.1M 
     CPU: 40.541s 
    CGroup: /system.slice/kubelet.service 
      ├─5519 /kubelet --api-servers=http://127.0.0.1:8080 --register-schedulable=false --cni-conf-dir=/etc/kubernetes/cni/net.d --network-plugin= --container-runtime=docker --allow-privileged=true --pod-manifest-path=/etc/kubernetes/ 
      └─5574 journalctl -k -f 

Aber kube-dns ist nicht in der Lage zu api-Server verbinden:

I0711 09:04:36.117052  1 dns.go:42] version: v1.6.0-alpha.0.680+3872cb93abf948-dirty 
I0711 09:04:36.117449  1 server.go:107] Using https://10.3.0.1:443 for kubernetes master, kubernetes API: <nil> 
I0711 09:04:36.118188  1 server.go:63] ConfigMap not configured, using values from command line flags 
I0711 09:04:36.118223  1 server.go:113] FLAG: --alsologtostderr="false" 
I0711 09:04:36.118234  1 server.go:113] FLAG: --config-map="" 
I0711 09:04:36.118241  1 server.go:113] FLAG: --config-map-namespace="kube-system" 
I0711 09:04:36.118246  1 server.go:113] FLAG: --dns-bind-address="0.0.0.0" 
I0711 09:04:36.118264  1 server.go:113] FLAG: --dns-port="10053" 
I0711 09:04:36.118271  1 server.go:113] FLAG: --domain="cluster.local." 
I0711 09:04:36.118277  1 server.go:113] FLAG: --federations="" 
I0711 09:04:36.118289  1 server.go:113] FLAG: --healthz-port="8081" 
I0711 09:04:36.118294  1 server.go:113] FLAG: --kube-master-url="" 
I0711 09:04:36.118299  1 server.go:113] FLAG: --kubecfg-file="" 
I0711 09:04:36.118303  1 server.go:113] FLAG: --log-backtrace-at=":0" 
I0711 09:04:36.118310  1 server.go:113] FLAG: --log-dir="" 
I0711 09:04:36.118315  1 server.go:113] FLAG: --log-flush-frequency="5s" 
I0711 09:04:36.118322  1 server.go:113] FLAG: --logtostderr="true" 
I0711 09:04:36.118327  1 server.go:113] FLAG: --stderrthreshold="2" 
I0711 09:04:36.118331  1 server.go:113] FLAG: --v="0" 
I0711 09:04:36.118335  1 server.go:113] FLAG: --version="false" 
I0711 09:04:36.118342  1 server.go:113] FLAG: --vmodule="" 
I0711 09:04:36.119467  1 server.go:155] Starting SkyDNS server (0.0.0.0:10053) 
I0711 09:04:36.119543  1 server.go:167] Skydns metrics not enabled 
I0711 09:04:36.119626  1 logs.go:41] skydns: ready for queries on cluster.local. for tcp://0.0.0.0:10053 [rcache 0] 
I0711 09:04:36.119644  1 logs.go:41] skydns: ready for queries on cluster.local. for udp://0.0.0.0:10053 [rcache 0] 
E0711 09:05:06.120481  1 reflector.go:199] pkg/dns/dns.go:145: Failed to list *api.Endpoints: Get https://10.3.0.1:443/api/v1/endpoints?resourceVersion=0: dial tcp 10.3.0.1:443: i/o timeout 
E0711 09:05:06.120729  1 reflector.go:199] pkg/dns/dns.go:148: Failed to list *api.Service: Get https://10.3.0.1:443/api/v1/services?resourceVersion=0: dial tcp 10.3.0.1:443: i/o timeout 

Logs von api Server:

[restful] 2017/07/11 07:52:32 log.go:30: [restful/swagger] listing is available at https://10.10.0.201:443/swaggerapi/ 
[restful] 2017/07/11 07:52:32 log.go:30: [restful/swagger] https://10.10.0.201:443/swaggerui/ is mapped to folder /swagger-ui/ 
I0711 07:52:32.740429  1 serve.go:79] Serving securely on 0.0.0.0:443 
I0711 07:52:32.740816  1 serve.go:94] Serving insecurely on 127.0.0.1:8080 
I0711 07:52:33.679354  1 trace.go:61] Trace "Update /api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication" (started 2017-07-11 07:52:32.965645672 +0000 UTC): 
[28.85µs] [28.85µs] About to convert to expected version 
[104.67µs] [75.82µs] Conversion done 
[111.099µs] [6.429µs] About to store object in database 
[713.576512ms] [713.465413ms] Object stored in database 
[713.584455ms] [7.943µs] Self-link added 
"Update /api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication" [713.659549ms] [75.094µs] END 
I0711 08:08:32.606430  1 trace.go:61] Trace "Update /api/v1/namespaces/kube-system/endpoints/kube-controller-manager" (started 2017-07-11 08:08:31.933189525 +0000 UTC): 
[8.907µs] [8.907µs] About to convert to expected version 
[19.758µs] [10.851µs] Conversion done 
[23.027µs] [3.269µs] About to store object in database 
[673.145516ms] [673.122489ms] Object stored in database 
[673.153091ms] [7.575µs] Self-link added 
"Update /api/v1/namespaces/kube-system/endpoints/kube-controller-manager" [673.202028ms] [48.937µs] END 
I0711 08:20:10.566203  1 trace.go:61] Trace "Update /api/v1/namespaces/kube-system/endpoints/kube-scheduler" (started 2017-07-11 08:20:07.032156665 +0000 UTC): 
[22.756µs] [22.756µs] About to convert to expected version 
[40.481µs] [17.725µs] Conversion done 
[44.63µs] [4.149µs] About to store object in database 
[3.533855608s] [3.533810978s] Object stored in database 
[3.53385947s] [3.862µs] Self-link added 
"Update /api/v1/namespaces/kube-system/endpoints/kube-scheduler" [3.53395749s] [98.02µs] END 
I0711 08:20:10.568558  1 trace.go:61] Trace "Update /api/v1/namespaces/kube-system/endpoints/kube-controller-manager" (started 2017-07-11 08:20:08.786760574 +0000 UTC): 
[12.63µs] [12.63µs] About to convert to expected version 
[29.044µs] [16.414µs] Conversion done 
[32.943µs] [3.899µs] About to store object in database 
[1.781715989s] [1.781683046s] Object stored in database 
[1.78171996s] [3.971µs] Self-link added 
"Update /api/v1/namespaces/kube-system/endpoints/kube-controller-manager" [1.781762523s] [42.563µs] END 
I0711 08:20:48.669858  1 trace.go:61] Trace "Update /api/v1/namespaces/kube-system/endpoints/kube-scheduler" (started 2017-07-11 08:20:45.030964285 +0000 UTC): 
[11.455µs] [11.455µs] About to convert to expected version 
[25.762µs] [14.307µs] Conversion done 
[29.427µs] [3.665µs] About to store object in database 
[3.638826479s] [3.638797052s] Object stored in database 
[3.638829618s] [3.139µs] Self-link added 
"Update /api/v1/namespaces/kube-system/endpoints/kube-scheduler" [3.638855999s] [26.381µs] END 
I0711 08:20:48.670137  1 trace.go:61] Trace "Update /api/v1/namespaces/kube-system/endpoints/kube-controller-manager" (started 2017-07-11 08:20:45.495019689 +0000 UTC): 
[13.604µs] [13.604µs] About to convert to expected version 
[33.752µs] [20.148µs] Conversion done 
[37.844µs] [4.092µs] About to store object in database 
[3.175049169s] [3.175011325s] Object stored in database 

Api Server ips :

# ip addr                         
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 
    inet 127.0.0.1/8 scope host lo 
     valid_lft forever preferred_lft forever 
    inet6 ::1/128 scope host 
     valid_lft forever preferred_lft forever 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 
    link/ether 5e:a7:f2:78:8d:04 brd ff:ff:ff:ff:ff:ff 
    inet 10.10.0.201/24 brd 10.10.0.255 scope global eth0 
     valid_lft forever preferred_lft forever 
    inet6 fe80::5ca7:f2ff:fe78:8d04/64 scope link 
     valid_lft forever preferred_lft forever 
3: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default 
    link/ether ae:1e:17:85:1b:63 brd ff:ff:ff:ff:ff:ff 
    inet 10.2.13.0/32 scope global flannel.1 
     valid_lft forever preferred_lft forever 
    inet6 fe80::ac1e:17ff:fe85:1b63/64 scope link 
     valid_lft forever preferred_lft forever 
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:06:e4:42:33 brd ff:ff:ff:ff:ff:ff 
    inet 172.17.0.1/16 scope global docker0 
     valid_lft forever preferred_lft forever 

DNS Service:

kubectl --namespace=kube-system get svc -o wide 
NAME     CLUSTER-IP EXTERNAL-IP PORT(S)   AGE  SELECTOR 
kube-dns    10.3.0.10 <none>  53/UDP,53/TCP 1h  k8s-app=kube-dns 

Answer 1

Von dem, was ich sehe, die API-Server-Adresse (10.10.0.201) und die API-Server-Adresse des DNS-Dienst zuzugreifen versucht (10.3.0.1) passen nicht zusammen. Der DNS-Dienst muss so konfiguriert sein, dass er 10.10.0.201 als API-Adresse verwendet.

Ich denke, die --api-servers=http://127.0.0.1:8080 in Kubelet (ich nehme an, dass der Kube-DNS-Dienst möglicherweise in einem anderen Knoten als der API-Server ausgeführt wird), kann die Ursache des Problems sein.