我是 k8s 的新手，并试图在没有任何自动化的情况下从头开始在 Vagrant（Ubuntu 16.04）中运行 3 节点（master + 2 workers）集群（v1.9.6）。我相信对于像我这样的初学者来说，这是获得实践经验的正确方法。老实说，我已经为此花费了一个多星期，感到绝望。
我的问题是 coredns pod（与 kube-dns 相同）无法通过 ClusterIP 访问 kube-apiserver。它看起来像这样：
vagrant@master-0:~$ kubectl get svc --all-namespaces
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 2d
kube-system kube-dns ClusterIP 10.0.30.1 <none> 53/UDP,53/TCP 2h
vagrant@master-0:~$ kubectl logs coredns-5c6d9fdb86-mffzk -n kube-system
E0330 15:40:45.476465 1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:319: Failed to list *v1.Namespace: Get https://10.0.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.0.0.1:443: i/o timeout
E0330 15:40:45.478241 1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:312: Failed to list *v1.Service: Get https://10.0.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.0.0.1:443: i/o timeout
E0330 15:40:45.478289 1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:314: Failed to list *v1.Endpoints: Get https://10.0.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.0.0.1:443: i/o timeout
同时，我可以从任何机器和 pod 内部 ping 10.0.0.1（使用busybox 进行测试），但 curl 不起作用。
掌握
接口
br-e468013fba9d Link encap:Ethernet HWaddr 02:42:8f:da:d3:35
inet addr:172.18.0.1 Bcast:172.18.255.255 Mask:255.255.0.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
docker0 Link encap:Ethernet HWaddr 02:42:d7:91:fd:9b
inet addr:172.17.0.1 Bcast:172.17.255.255 Mask:255.255.0.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
enp0s3 Link encap:Ethernet HWaddr 02:74:f2:80:ad:a4
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::74:f2ff:fe80:ada4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3521 errors:0 dropped:0 overruns:0 frame:0
TX packets:2116 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:784841 (784.8 KB) TX bytes:221888 (221.8 KB)
enp0s8 Link encap:Ethernet HWaddr 08:00:27:45:ed:ec
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe45:edec/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:322839 errors:0 dropped:0 overruns:0 frame:0
TX packets:329938 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:45879993 (45.8 MB) TX bytes:89279972 (89.2 MB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:249239 errors:0 dropped:0 overruns:0 frame:0
TX packets:249239 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:75677355 (75.6 MB) TX bytes:75677355 (75.6 MB)
iptables
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
-N DOCKER
-N DOCKER-ISOLATION
-N DOCKER-USER
-A FORWARD -j DOCKER-USER
-A FORWARD -j DOCKER-ISOLATION
-A FORWARD -o docker0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -o docker0 -j DOCKER
-A FORWARD -i docker0 ! -o docker0 -j ACCEPT
-A FORWARD -i docker0 -o docker0 -j ACCEPT
-A FORWARD -o br-e468013fba9d -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -o br-e468013fba9d -j DOCKER
-A FORWARD -i br-e468013fba9d ! -o br-e468013fba9d -j ACCEPT
-A FORWARD -i br-e468013fba9d -o br-e468013fba9d -j ACCEPT
-A DOCKER-ISOLATION -i br-e468013fba9d -o docker0 -j DROP
-A DOCKER-ISOLATION -i docker0 -o br-e468013fba9d -j DROP
-A DOCKER-ISOLATION -j RETURN
-A DOCKER-USER -j RETURN
路线
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 10.0.2.2 0.0.0.0 UG 0 0 0 enp0s3
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 enp0s3
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
172.18.0.0 0.0.0.0 255.255.0.0 U 0 0 0 br-e468013fba9d
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 enp0s8
kube-apiserver (docker-compose)
version: '3'
services:
kube_apiserver:
image: gcr.io/google-containers/hyperkube:v1.9.6
restart: always
network_mode: host
container_name: kube-apiserver
ports:
- "8080"
volumes:
- "/var/lib/kubernetes/ca-key.pem:/var/lib/kubernetes/ca-key.pem"
- "/var/lib/kubernetes/ca.pem:/var/lib/kubernetes/ca.pem"
- "/var/lib/kubernetes/kubernetes.pem:/var/lib/kubernetes/kubernetes.pem"
- "/var/lib/kubernetes/kubernetes-key.pem:/var/lib/kubernetes/kubernetes-key.pem"
command: ["/usr/local/bin/kube-apiserver",
"--admission-control", "Initializers,NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota",
"--advertise-address", "192.168.0.1",
"--etcd-servers", "http://192.168.0.1:2379,http://192.168.0.2:2379,http://192.168.0.3:2379",
"--insecure-bind-address", "127.0.0.1",
"--insecure-port", "8080",
"--kubelet-https", "true",
"--service-cluster-ip-range", "10.0.0.0/16",
"--allow-privileged", "true",
"--runtime-config", "api/all",
"--service-account-key-file", "/var/lib/kubernetes/ca-key.pem",
"--client-ca-file", "/var/lib/kubernetes/ca.pem",
"--tls-ca-file", "/var/lib/kubernetes/ca.pem",
"--tls-cert-file", "/var/lib/kubernetes/kubernetes.pem",
"--tls-private-key-file", "/var/lib/kubernetes/kubernetes-key.pem",
"--kubelet-certificate-authority", "/var/lib/kubernetes/ca.pem",
"--kubelet-client-certificate", "/var/lib/kubernetes/kubernetes.pem",
"--kubelet-client-key", "/var/lib/kubernetes/kubernetes-key.pem"]
kube-controller-manager (docker-compose)
version: '3'
services:
kube_controller_manager:
image: gcr.io/google-containers/hyperkube:v1.9.6
restart: always
network_mode: host
container_name: kube-controller-manager
ports:
- "10252"
volumes:
- "/var/lib/kubernetes/ca-key.pem:/var/lib/kubernetes/ca-key.pem"
- "/var/lib/kubernetes/ca.pem:/var/lib/kubernetes/ca.pem"
command: ["/usr/local/bin/kube-controller-manager",
"--allocate-node-cidrs", "true",
"--cluster-cidr", "10.10.0.0/16",
"--master", "http://127.0.0.1:8080",
"--port", "10252",
"--service-cluster-ip-range", "10.0.0.0/16",
"--leader-elect", "false",
"--service-account-private-key-file", "/var/lib/kubernetes/ca-key.pem",
"--root-ca-file", "/var/lib/kubernetes/ca.pem"]
kube-调度程序（docker-compose）
version: '3'
services:
kube_scheduler:
image: gcr.io/google-containers/hyperkube:v1.9.6
restart: always
network_mode: host
container_name: kube-scheduler
ports:
- "10252"
command: ["/usr/local/bin/kube-scheduler",
"--master", "http://127.0.0.1:8080",
"--port", "10251"]
工人0
接口
br-c5e101440189 Link encap:Ethernet HWaddr 02:42:60:ba:c9:81
inet addr:172.18.0.1 Bcast:172.18.255.255 Mask:255.255.0.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
cbr0 Link encap:Ethernet HWaddr ae:48:89:15:60:fd
inet addr:10.10.0.1 Bcast:10.10.0.255 Mask:255.255.255.0
inet6 addr: fe80::a406:b0ff:fe1d:1d85/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1149 errors:0 dropped:0 overruns:0 frame:0
TX packets:409 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:72487 (72.4 KB) TX bytes:35650 (35.6 KB)
enp0s3 Link encap:Ethernet HWaddr 02:74:f2:80:ad:a4
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::74:f2ff:fe80:ada4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3330 errors:0 dropped:0 overruns:0 frame:0
TX packets:2269 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:770147 (770.1 KB) TX bytes:246770 (246.7 KB)
enp0s8 Link encap:Ethernet HWaddr 08:00:27:07:69:06
inet addr:192.168.0.2 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe07:6906/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:268762 errors:0 dropped:0 overruns:0 frame:0
TX packets:258080 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:48488207 (48.4 MB) TX bytes:25791040 (25.7 MB)
flannel.1 Link encap:Ethernet HWaddr 86:8e:2f:c4:98:82
inet addr:10.10.0.0 Bcast:0.0.0.0 Mask:255.255.255.255
inet6 addr: fe80::848e:2fff:fec4:9882/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1450 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:8 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:2955 errors:0 dropped:0 overruns:0 frame:0
TX packets:2955 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:218772 (218.7 KB) TX bytes:218772 (218.7 KB)
vethe5d2604 Link encap:Ethernet HWaddr ae:48:89:15:60:fd
inet6 addr: fe80::ac48:89ff:fe15:60fd/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:828 (828.0 B)
iptables
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
-N DOCKER
-N DOCKER-ISOLATION
-N DOCKER-USER
-N KUBE-FIREWALL
-N KUBE-FORWARD
-N KUBE-SERVICES
-A INPUT -j KUBE-FIREWALL
-A INPUT -m comment --comment "kubernetes service portals" -j KUBE-SERVICES
-A FORWARD -j DOCKER-USER
-A FORWARD -m comment --comment "kubernetes forward rules" -j KUBE-FORWARD
-A FORWARD -s 10.0.0.0/16 -j ACCEPT
-A FORWARD -d 10.0.0.0/16 -j ACCEPT
-A OUTPUT -j KUBE-FIREWALL
-A OUTPUT -m comment --comment "kubernetes service portals" -j KUBE-SERVICES
-A DOCKER-USER -j RETURN
-A KUBE-FIREWALL -m comment --comment "kubernetes firewall for dropping marked packets" -m mark --mark 0x8000/0x8000 -j DROP
-A KUBE-FORWARD -m comment --comment "kubernetes forwarding rules" -m mark --mark 0x4000/0x4000 -j ACCEPT
-A KUBE-FORWARD -s 10.10.0.0/16 -m comment --comment "kubernetes forwarding conntrack pod source rule" -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A KUBE-FORWARD -d 10.10.0.0/16 -m comment --comment "kubernetes forwarding conntrack pod destination rule" -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
路线
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 10.0.2.2 0.0.0.0 UG 0 0 0 enp0s3
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 enp0s3
10.10.0.0 0.0.0.0 255.255.255.0 U 0 0 0 cbr0
10.10.1.0 10.10.1.0 255.255.255.0 UG 0 0 0 flannel.1
172.18.0.0 0.0.0.0 255.255.0.0 U 0 0 0 br-c5e101440189
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 enp0s8
kubelet（系统服务）
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/kubernetes/kubernetes
#After=docker.service
#Requires=docker.service
[Service]
ExecStart=/usr/local/bin/kubelet \
--allow-privileged=true \
--anonymous-auth=false \
--authorization-mode=AlwaysAllow \
--cloud-provider= \
--cluster-dns=10.0.30.1 \
--cluster-domain=cluster.local \
--node-ip=192.168.0.2 \
--pod-cidr=10.10.0.0/24 \
--kubeconfig=/var/lib/kubelet/kubeconfig \
--runtime-request-timeout=15m \
--hostname-override=worker0 \
# --read-only-port=10255 \
--client-ca-file=/var/lib/kubernetes/ca.pem \
--tls-cert-file=/var/lib/kubelet/worker0.pem \
--tls-private-key-file=/var/lib/kubelet/worker0-key.pem
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
kube-proxy（系统服务）
[Unit]
Description=Kubernetes Kube Proxy
Documentation=https://github.com/kubernetes/kubernetes
#After=docker.service
#Requires=docker.service
[Service]
ExecStart=/usr/local/bin/kube-proxy \
--cluster-cidr=10.10.0.0/16 \
--kubeconfig=/var/lib/kube-proxy/kubeconfig \
--v=5
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
Worker1 的配置与 worker0 非常相似。
如果需要任何其他信息，请告诉我。