Kubernetes实战[1]: 基于kubernetes构建Docker集群环境实战

kubernetes是google公司基于docker所做的一个分布式集群，有以下主件组成

　　etcd: 高可用存储共享配置和服务发现，作为与minion机器上的flannel配套使用，作用是使每台 minion上运行的docker拥有不同的ip段，最终目的是使不同minion上正在运行的docker containner都有一个与别的任意一个containner（别的minion上运行的docker containner）不一样的IP地址。

　　flannel: 网络结构支持

　　kube-apiserver: 不论通过kubectl还是使用remote api 直接控制，都要经过apiserver

　　kube-controller-manager: 对replication controller, endpoints controller, namespace controller, and serviceaccounts controller的循环控制，与kube-apiserver交互，保证这些controller工作

　　kube-scheduler: Kubernetes scheduler的作用就是根据特定的调度算法将pod调度到指定的工作节点（minion）上，这一过程也叫绑定（bind)

　　kubelet: Kubelet运行在Kubernetes Minion Node上. 它是container agent的逻辑继任者

　　kube-proxy: kube-proxy是kubernetes 里运行在minion节点上的一个组件, 它起的作用是一个服务代理的角色

图为GIT+Jenkins+Kubernetes+Docker+Etcd+confd+Nginx+Glusterfs架构：

1、环境介绍及准备：

1.1 物理机操作系统

　　物理机操作系统采用Centos7.4 64位，细节如下。

[root@etcd ~]# uname -a
Linux etcd 3.10.0-693.el7.x86_64 #1 SMP Tue Aug 22 21:09:27 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
[root@etcd ~]# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)

1.2 主机信息

　　本文准备了五台机器用于部署k8s的运行环境(可把Master、etcd、registry放在同一台上)，细节如下：

| 节点 | 主机名 | IP |

| Etcd | etcd | 10.0.0.10 |

| Kubernetes Master | k8s-master | 10.0.0.11 |

| Kubernetes Node 1 | k8s-node-1 | 10.0.0.12 |

| Kubernetes Node 2 | k8s-node-2 | 10.0.0.13 |

| Kubernetes Node 3 | k8s-node-3 | 10.0.0.14 |

设置五台机器的主机名：

　　Etcd上执行：

[root@localhost ~]#  hostnamectl --static set-hostname  etcd

　　Master上执行：

[root@localhost ~]#  hostnamectl --static set-hostname  k8s-master

　　Node1上执行：

[root@localhost ~]#  hostnamectl --static set-hostname  k8s-node-1

　　Node2上执行：

[root@localhost ~]# hostnamectl --static set-hostname  k8s-node-2

　　Node3上执行：

[root@localhost ~]# hostnamectl --static set-hostname  k8s-node-3

　　在五台机器上设置hosts，均执行如下命令：

echo '10.0.0.10    etcd                 #添加hosts解析
10.0.0.11    k8s-master
10.0.0.12    k8s-node-1
10.0.0.13    k8s-node-2
10.0.0.14    k8s-node-3
10.0.0.10    kube-registry' >> /etc/hosts

1.3 关闭五台机器上的防火墙

systemctl disable firewalld.service
systemctl stop firewalld.service

安装NTP并启动

# yum -y install ntp
# systemctl start ntpd
# systemctl enable ntpd

2、部署etcd

　k8s运行依赖etcd，需要先部署etcd，本文采用yum方式安装：

[root@etcd ~]# yum install etcd -y

yum安装的etcd默认配置文件在/etc/etcd/etcd.conf。编辑配置文件，更改以下带颜色部分信息：

# [member]
ETCD_NAME=master                             #<----修改这行
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
#ETCD_WAL_DIR=""
#ETCD_SNAPSHOT_COUNT="10000"
#ETCD_HEARTBEAT_INTERVAL="100"
#ETCD_ELECTION_TIMEOUT="1000"
#ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379,http://0.0.0.0:4001"
#修改这行，2379是默认的使用端口，为了防止端口占用问题的出现，增加4001端口备用。
#ETCD_MAX_SNAPSHOTS="5"
#ETCD_MAX_WALS="5"
#ETCD_CORS=""
#
#[cluster]
#ETCD_INITIAL_ADVERTISE_PEER_URLS="http://localhost:2380"
# if you use different ETCD_NAME (e.g. test), set ETCD_INITIAL_CLUSTER value for this name, i.e. "test=http://..."
#ETCD_INITIAL_CLUSTER="default=http://localhost:2380"
#ETCD_INITIAL_CLUSTER_STATE="new"
#ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://etcd:2379,http://etcd:4001"       #<----修改这行
#ETCD_DISCOVERY=""
#ETCD_DISCOVERY_SRV=""
#ETCD_DISCOVERY_FALLBACK="proxy"
#ETCD_DISCOVERY_PROXY=""

启动并验证状态

[root@etcd ~]# systemctl enable etcd
[root@etcd ~]# systemctl start etcd
[root@etcd ~]# etcdctl set testdir/testkey0 0
0
[root@etcd ~]# etcdctl get testdir/testkey0
0
[root@etcd ~]# etcdctl -C http://etcd:4001 cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://etcd:2379
cluster is healthy
[root@etcd ~]# etcdctl -C http://etcd:2379 cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://etcd:2379
cluster is healthy

3、部署master

3.1 安装Docker

[root@k8s-master ~]# yum install -y docker

配置Docker配置文件，使其允许从registry中拉取镜像。

[root@k8s-master ~]# vim /etc/sysconfig/docker
# /etc/sysconfig/docker
# Modify these options if you want to change the way the docker daemon runs
OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false'
if [ -z "${DOCKER_CERT_PATH}" ]; thenDOCKER_CERT_PATH=/etc/docker
fi
OPTIONS='--insecure-registry registry:5000'

设置开机自启动并开启服务

[root@k8s-master ~]# chkconfig docker on
Note: Forwarding request to 'systemctl enable docker.service'.
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
[root@k8s-master ~]# service docker start
Redirecting to /bin/systemctl start docker.service

3.2 安装kubernets

[root@k8s-master ~]# yum install -y kubernetes

3.3 配置并启动kubernetes

在kubernetes master上需要运行以下组件：

　　　　Kubernets API Server

　　　　Kubernets Controller Manager

　　　　Kubernets Scheduler

相应的要更改以下几个配置中带颜色部分信息：

3.3.1 /etc/kubernetes/apiserver

[root@k8s-master ~]# cat /etc/kubernetes/apiserver
###
# kubernetes system config
#
# The following values are used to configure the kube-apiserver
#
# The address on the local server to listen to.
KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"          #<----修改这行
# The port on the local server to listen on.
KUBE_API_PORT="--port=8080"                                 #<----修改这行
# Port minions listen on
# KUBELET_PORT="--kubelet-port=10250"
# Comma separated list of nodes in the etcd cluster
KUBE_ETCD_SERVERS="--etcd-servers=http://etcd:2379"        #<----修改这行
# Address range to use for services
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
# default admission control policies
KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"   #<----修改这行
# Add your own!
KUBE_API_ARGS=""

3.3.2 /etc/kubernetes/config

[root@k8s-master ~]# cat /etc/kubernetes/config
###
# kubernetes system config
#
# The following values are used to configure various aspects of all
# kubernetes services, including
#
#   kube-apiserver.service
#   kube-controller-manager.service
#   kube-scheduler.service
#   kubelet.service
#   kube-proxy.service
# logging to stderr means we get it in the systemd journal
KUBE_LOGTOSTDERR="--logtostderr=true"
# journal message level, 0 is debug
KUBE_LOG_LEVEL="--v=0"
# Should this cluster be allowed to run privileged docker containers
KUBE_ALLOW_PRIV="--allow-privileged=false"
# How the controller-manager, scheduler, and proxy find the apiserver
KUBE_MASTER="--master=http://k8s-master:8080"                  #<----修改这行

启动服务并设置开机自启动

[root@k8s-master ~]# systemctl enable kube-apiserver.service
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-apiserver.service to /usr/lib/systemd/system/kube-apiserver.service.
[root@k8s-master ~]# systemctl start kube-apiserver.service
[root@k8s-master ~]# systemctl enable kube-controller-manager.service
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-controller-manager.service to /usr/lib/systemd/system/kube-controller-manager.service.
[root@k8s-master ~]# systemctl start kube-controller-manager.service
[root@k8s-master ~]# systemctl enable kube-scheduler.service
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-scheduler.service to /usr/lib/systemd/system/kube-scheduler.service.
[root@k8s-master ~]# systemctl start kube-scheduler.service

4、部署node

4.1 安装docker

　　参见3.1

[root@k8s-node-1 ~]# yum install -y docker

配置Docker配置文件，使其允许从registry中拉取镜像。

[root@k8s-node-1 ~]# vim /etc/sysconfig/docker# /etc/sysconfig/docker# Modify these options if you want to change the way the docker daemon runs
OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false'
if [ -z "${DOCKER_CERT_PATH}" ]; thenDOCKER_CERT_PATH=/etc/docker
fi
OPTIONS='--insecure-registry kube-registry:5000'     #添加这行kube-registry:5000,需要/etc/hosts解析

[root@k8s-master ~]# chkconfig docker on
[root@k8s-master ~]# service docker start

4.2 安装kubernets

　　参见3.2

[root@k8s-master ~]# yum install -y kubernetes

4.3 配置并启动kubernetes

　　在kubernetes node上需要运行以下组件：

　　　　Kubelet

　　　　Kubernets Proxy

相应的要更改以下几个配置文中带颜色部分信息：

4.3.1 /etc/kubernetes/config

[root@k8s-node-1 ~]# cat /etc/kubernetes/config
###
# kubernetes system config
#
# The following values are used to configure various aspects of all
# kubernetes services, including
#
#   kube-apiserver.service
#   kube-controller-manager.service
#   kube-scheduler.service
#   kubelet.service
#   kube-proxy.service
# logging to stderr means we get it in the systemd journal
KUBE_LOGTOSTDERR="--logtostderr=true"
# journal message level, 0 is debug
KUBE_LOG_LEVEL="--v=0"
# Should this cluster be allowed to run privileged docker containers
KUBE_ALLOW_PRIV="--allow-privileged=false"
# How the controller-manager, scheduler, and proxy find the apiserver
KUBE_MASTER="--master=http://k8s-master:8080"        #修改

4.3.2 /etc/kubernetes/kubelet

[root@k8s-node-1 ~]# cat /etc/kubernetes/kubelet
###
# kubernetes kubelet (minion) config
# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=0.0.0.0"        #修改
# The port for the info server to serve on
# KUBELET_PORT="--port=10250"
# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=k8s-node-1"        #修改
# location of the api-server
KUBELET_API_SERVER="--api-servers=http://k8s-master:8080"        #修改# pod infrastructure container
#KUBELET_POD_INFRA_CONTAINER:Pod 启动时的一个基础容器,这里使用自建的pod-infrastructure
#KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=kube-registry:5000"       #修改，上面默认的基础容器无法下载# Add your own!
KUBELET_ARGS=""

启动服务并设置开机自启动

[root@k8s-node-1 ~]# systemctl enable kubelet.service
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
[root@k8s-node-1 ~]# systemctl start kubelet.service
[root@k8s-node-1 ~]# systemctl enable kube-proxy.service
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-proxy.service to /usr/lib/systemd/system/kube-proxy.service.
[root@k8s-node-1 ~]# systemctl start kube-proxy.service

4.4 查看状态，查询Kubernetes的健康状态

　　在master上查看集群中节点及节点状态

[root@k8s-master ~]# kubectl -s http://k8s-master:8080 get node
NAME         STATUS    AGE
k8s-node-1   Ready     5m
[root@k8s-master ~]# kubectl get nodes
NAME         STATUS    AGE
k8s-node-1   Ready     5m

其他的k8s-node-2，k8s-node-3只需修改：

[root@k8s-node-2 ~]# vi /etc/kubernetes/kubelet
......
# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=k8s-node-2"
......

k8s-node-1，k8s-node-2，k8s-node-3节点部署node后，完成后查看状态：

#<---查询Kubernetes Master各组件的健康状态
[root@k8s-master ~]# kubectl -s http://k8s-master:8080 get node
NAME         STATUS    AGE
k8s-node-1        Ready     40m
k8s-node-2        Ready     5m
k8s-node-3        Ready     23s#<---查询Kubernetes Node的健康状态
[root@k8s-master ~]# kubectl -s http://k8s-master:8080 get node
NAME         STATUS    AGE
k8s-node-1        Ready     3d
k8s-node-2        Ready     3d
k8s-node-3        Ready     3d
[root@k8s-master ~]# kubectl get nodes
NAME         STATUS    AGE
k8s-node-1   Ready     40m
k8s-node-2   Ready     5m
k8s-node-3   Ready     25s

至此，已经搭建了一个kubernetes集群，但目前该集群还不能很好的工作，请继续后续的步骤。

5、创建覆盖网络——Flannel

5.1 安装Flannel

　　在master、node上均执行如下命令，进行安装

[root@k8s-master ~]# yum install -y flannel

5.2 配置Flannel

　　master、node上均编辑/etc/sysconfig/flanneld，修改红色部分

[root@k8s-master ~]# cat /etc/sysconfig/flanneld
# Flanneld configuration options
# etcd url location.  Point this to the server where etcd runs
FLANNEL_ETCD_ENDPOINTS="http://etcd:2379"             #<----修改
# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_PREFIX="/atomic.io/network"
# Any additional options that you want to pass
#FLANNEL_OPTIONS=""

5.3 配置etcd中关于flannel的key

Kubernetes的网络模型要求每一个Pod都拥有一个扁平化共享网络命名空间的IP,称为PodIP，Pod能够直接通过PodIP跨网络与其他物理机和Pod进行通信。要实现Kubernetes的网络模型，需要在Kubernetes集群中创建一个覆盖网络(Overlay Network)，联通各个节点，目前可以通过第三方网络插件来创建覆盖网络，比如Flannel和Open vSwitch。

Flannel会为不同Node的Docker网桥配置不同的IP网段以保证Docker容器的IP在集群内唯一，所以Flannel会重新配置Docker网桥，需要先删除原先创建的Docker网桥（每台机器需要执行）：

# iptables -t nat -F
# ifconfig docker0 down
# brctl delbr docker0

　　Flannel使用Etcd进行配置，来保证多个Flannel实例之间的配置一致性，所以需要在etcd上进行如下配置：（‘/atomic.io/network/config’这个key与上文/etc/sysconfig/flannel中的配置项FLANNEL_ETCD_PREFIX是相对应的，错误的话启动就会出错）

[root@etcd ~]# etcdctl mk /atomic.io/network/config '{ "Network": "10.0.0.0/24" }'
{ "Network": "10.0.0.0/24" }
[root@etcd ~]# etcdctl get /atomic.io/network/config
{ "Network": "10.0.0.0/24" }

[root@k8s-node-1 ~]# systemctl status flanneld.service    #不能和物理机取相同的网段
● flanneld.service - Flanneld overlay address etcd agentLoaded: loaded (/usr/lib/systemd/system/flanneld.service; disabled; vendor preset: disabled)Active: active (running) since Thu 2018-05-31 17:01:42 CST; 4s agoProcess: 74016 ExecStartPost=/usr/libexec/flannel/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker (code=exited, status=0/SUCCESS)Main PID: 73955 (flanneld)Memory: 16.7MCGroup: /system.slice/flanneld.service└─73955 /usr/bin/flanneld -etcd-endpoints=http://etcd:2379 -etcd-prefix=/atomic.io/network --iface=ens33
May 31 17:01:36 k8s-node-1 flanneld-start[73955]: E0531 17:01:36.996778   73955 network.go:102] failed to retrieve network config: 100: Key not... [11633]
May 31 17:01:38 k8s-node-1 flanneld-start[73955]: E0531 17:01:38.000029   73955 network.go:102] failed to retrieve network config: 100: Key not... [11633]
May 31 17:01:39 k8s-node-1 flanneld-start[73955]: E0531 17:01:39.003675   73955 network.go:102] failed to retrieve network config: 100: Key not... [11633]
May 31 17:01:40 k8s-node-1 flanneld-start[73955]: E0531 17:01:40.006161   73955 network.go:102] failed to retrieve network config: 100: Key not... [11633]
May 31 17:01:41 k8s-node-1 flanneld-start[73955]: E0531 17:01:41.007743   73955 network.go:102] failed to retrieve network config: 100: Key not... [11633]
May 31 17:01:42 k8s-node-1 flanneld-start[73955]: I0531 17:01:42.016595   73955 local_manager.go:179] Picking subnet in range 10.0.1.0 ... 10.0.255.0
May 31 17:01:42 k8s-node-1 flanneld-start[73955]: I0531 17:01:42.055551   73955 manager.go:250] Lease acquired: 10.0.74.0/24
May 31 17:01:42 k8s-node-1 flanneld-start[73955]: I0531 17:01:42.056475   73955 network.go:98] Watching for new subnet leases
May 31 17:01:42 k8s-node-1 flanneld-start[73955]: I0531 17:01:42.081693   73955 network.go:191] Subnet added: 10.0.0.128/25
May 31 17:01:42 k8s-node-1 systemd[1]: Started Flanneld overlay address etcd agent.
Hint: Some lines were ellipsized, use -l to show in full.

[root@etcd ~]# etcdctl rm /atomic.io/network/config
PrevNode.Value: { "Network": "10.0.0.0/24" }
[root@etcd ~]# etcdctl get /atomic.io/network/config
Error:  100: Key not found (/atomic.io/network/config) [11633]

所以设置成不同的网段

（例子：

etcdctl mk /coreos.com/network/config '{"Network":"172.17.0.0/16", "SubnetMin": "172.17.1.0", "SubnetMax": "172.17.254.0"}'

[root@etcd ~]# etcdctl mk /atomic.io/network/config '{ "Network": "10.0.0.0/16" }'
{ "Network": "10.0.0.0/16" }
[root@etcd ~]# etcdctl get /atomic.io/network/config
{ "Network": "10.0.0.0/16" }

5.4 启动

启动Flannel之后，需要依次重启docker、kubernete。

　　在master执行：

systemctl enable flanneld.service
systemctl start flanneld.service
service docker restart
systemctl restart kube-apiserver.service
systemctl restart kube-controller-manager.service
systemctl restart kube-scheduler.service

　　在node上执行：

systemctl enable flanneld.service
systemctl start flanneld.service
service docker restart
systemctl restart kubelet.service
systemctl restart kube-proxy.service

kube-apiserver：位于master节点，接受用户请求。
kube-scheduler：位于master节点，负责资源调度，即pod建在哪个node节点。
kube-controller-manager：位于master节点，包含ReplicationManager，Endpointscontroller，Namespacecontroller，Nodecontroller等。
etcd：分布式键值存储系统，共享整个集群的资源对象信息。
kubelet：位于node节点，负责维护在特定主机上运行的pod。
kube-proxy：位于node节点，它起的作用是一个服务代理的角色。

工作流程：

① kubectl 发送部署请求到 API Server。

② API Server 通知 Controller Manager 创建一个 deployment 资源。

③ Scheduler 执行调度任务，将两个副本 Pod 分发到 k8s-node1 和 k8s-node2。

④ k8s-node1 和 k8s-node2 上的 kubectl 在各自的节点上创建并运行 Pod。

[root@k8s-master ~]# kubectl get cs        #查询各个组件的健康状态
NAME                 STATUS    MESSAGE              ERROR
controller-manager         Healthy     ok
scheduler             Healthy     ok
etcd-0               Healthy    {"health": "true"}

---------------------------------------

[root@k8s-master ~]# kube-apiserver --version

Kubernetes v1.5.2

[root@k8s-master ~]# flanneld -version

0.7.1

[root@etcd ~]# etcd -version

etcd Version: 3.2.18

Git SHA: eddf599

Go Version: go1.9.4

Go OS/Arch: linux/amd64

--------------------------------------------

推广：

Flannel会为不同Node的Dokcer网桥配置不同的IP网段以保证Docker容器的IP在集群内唯一。

所以Flannel会重新配置Docker网桥。需要删除原先创建的Dokcer网桥。

[root@k8s-master ~]# ip link set docker0 down      //关闭docker0网桥
[root@k8s-master ~]# ip link delete docker0        //删除docker0网桥

[root@k8s-master ~]# ip a s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope host valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000link/ether 00:0c:29:f0:be:d7 brd ff:ff:ff:ff:ff:ffinet 10.0.0.11/24 brd 10.0.0.255 scope global ens33valid_lft forever preferred_lft foreverinet6 fe80::c0f:685e:be9c:a067/64 scope link tentative dadfailed valid_lft forever preferred_lft foreverinet6 fe80::25bc:f2cb:4ac9:4aff/64 scope link tentative dadfailed valid_lft forever preferred_lft foreverinet6 fe80::5095:3b33:58b4:46a4/64 scope link tentative dadfailed valid_lft forever preferred_lft forever
3: flannel0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1472 qdisc pfifo_fast state UNKNOWN qlen 500link/none inet 10.0.20.0/16 scope global flannel0valid_lft forever preferred_lft foreverinet6 fe80::2ab2:fede:73d1:9c7/64 scope link flags 800 valid_lft forever preferred_lft forever

[root@k8s-master ~]# systemctl restart flanneld docker

操作完成后，可以进行验证。
每个Node会有docker0和flannel0这2个网卡。这2个网卡在不同的Node下都是不同的.

[root@k8s-master ~]# ip a s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope host valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000link/ether 00:0c:29:f0:be:d7 brd ff:ff:ff:ff:ff:ffinet 10.0.0.11/24 brd 10.0.0.255 scope global ens33valid_lft forever preferred_lft foreverinet6 fe80::c0f:685e:be9c:a067/64 scope link tentative dadfailed valid_lft forever preferred_lft foreverinet6 fe80::25bc:f2cb:4ac9:4aff/64 scope link tentative dadfailed valid_lft forever preferred_lft foreverinet6 fe80::5095:3b33:58b4:46a4/64 scope link tentative dadfailed valid_lft forever preferred_lft forever
4: flannel0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1472 qdisc pfifo_fast state UNKNOWN qlen 500link/none inet 10.0.20.0/16 scope global flannel0valid_lft forever preferred_lft foreverinet6 fe80::48ef:305f:a9af:6b4c/64 scope link flags 800 valid_lft forever preferred_lft forever
5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN link/ether 02:42:62:01:91:e2 brd ff:ff:ff:ff:ff:ffinet 10.0.20.1/24 scope global docker0valid_lft forever preferred_lft forever

[root@k8s-master ~]# kubectl get services

NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE

kubernetes 10.254.0.1 <none> 443/TCP 7h

[root@k8s-master ~]# kubectl get pod -o wide

No resources found.

转载于:https://blog.51cto.com/sf1314/2122143