根据以下内容安装kubernetes：https://coreos.com/kubernetes/docs/latest/getting-started.html我无法设置dns插件。
Kubelet正在运行：
● 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
但是kube-dns无法连接到api-server：
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
来自api服务器的日志：
[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服务器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服务：
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
答案 0 :(得分：0)
从我看到的，API服务器地址（10.10.0.201）和DNS服务尝试访问的API服务器地址（10.3.0.1）不匹配。必须将DNS服务配置为使用10.10.0.201作为API地址。
我认为Kubelet中的--api-servers=http://127.0.0.1:8080（我假设kube-dns服务可能在与api服务器不同的节点中运行）可能是问题的原因。