准备工作

在京东云买了三台云主机,配置如下

主机名 角色 内网ip CPU核数 内存 磁盘 操作系统 内核
JD1 master 10.0.0.3 2 4GB 40GB CentOS 7.3 3.10.0
JD2 worker 10.0.0.4 2 4GB 40GB CentOS 7.3 3.10.0
JD3 worker 10.0.0.5 2 4GB 40GB CentOS 7.3 3.10.0

配置kubernetes yum源

京东云自带的yum源无kubernetes,需要添加阿里云的源

vim /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
gpgcheck=0
enable=1

yum clean all && yum makecache

测试

[root@JD1 yum.repos.d]# yum list | grep kubeadm
kubeadm.x86_64                            1.17.2-0                       kubernetes

安装 Docker

三台机器上都需要安装

[root@JD1 ~]# yum install docker -y
[root@JD1 ~]# systemctl start docker
[root@JD1 ~]# systemctl enable docker
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
[root@JD1 yum.repos.d]# docker version
Client:
 Version:         1.13.1
 API version:     1.26
 Package version: docker-1.13.1-103.git7f2769b.el7.centos.x86_64
 Go version:      go1.10.3
 Git commit:      7f2769b/1.13.1
 Built:           Sun Sep 15 14:06:47 2019
 OS/Arch:         linux/amd64

Server:
 Version:         1.13.1
 API version:     1.26 (minimum version 1.12)
 Package version: docker-1.13.1-103.git7f2769b.el7.centos.x86_64
 Go version:      go1.10.3
 Git commit:      7f2769b/1.13.1
 Built:           Sun Sep 15 14:06:47 2019
 OS/Arch:         linux/amd64
 Experimental:    false

安装 kubeadm

三台机器上都需要安装

yum install kubeadm -y
......
Installed:
  kubeadm.x86_64 0:1.17.2-0

Dependency Installed:
  conntrack-tools.x86_64 0:1.4.4-5.el7_7.2          cri-tools.x86_64 0:1.13.0-0
  kubectl.x86_64 0:1.17.2-0                         kubelet.x86_64 0:1.17.2-0
  kubernetes-cni.x86_64 0:0.7.5-0                   libnetfilter_cthelper.x86_64 0:1.0.0-10.el7_7.1
  libnetfilter_cttimeout.x86_64 0:1.0.0-6.el7_7.1   libnetfilter_queue.x86_64 0:1.0.2-2.el7_2
  socat.x86_64 0:1.7.3.2-2.el7

kubelet、kubectl、kubenetes-cni也跟着一起安装好了

配置kubelet开机启动

systemctl enable kubelet

部署 Master节点

以jd1作为master节点,另外两台为worker节点

方法一:命令行

kubeadm init --kubernetes-version=v1.17.2  \
    --pod-network-cidr=10.244.0.0/16  \
    --service-cidr=10.96.0.0/12  \
    --apiserver-advertise-address=10.0.0.3

方法二:配置文件(推荐,本次也采用该方式)

使用kubeadm配置文件,由于本次下载的kubeadm版本过高,安装低版本k8s集群时报错,索性就安装最新版本的k8s了。

# 生成配置文件
kubeadm config print init-defaults ClusterConfiguration >kubeadm.yaml

修改默认镜像仓库,由于大家都懂得的原因,谷歌默认容器镜像地址k8s.gcr.io无法访问,修改为registry.cn-hangzhou.aliyuncs.com/google_containers

vim kubeadm.yaml
#修改 imageRepository: k8s.gcr.io
#改为 imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
#修改 advertiseAddress: 1.2.3.4
#改为 advertiseAddress: 10.0.0.3

最终版本

apiVersion: kubeadm.k8s.io/v1beta2
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 10.0.0.3
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: jd1
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.17.2
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.96.0.0/12
scheduler: {}

查看kubeadm config所需的镜像,更多kubeadm config命令

[root@JD1 ~]# kubeadm config images list --config kubeadm.yaml
W0126 20:54:01.849570    9619 validation.go:28] Cannot validate kube-proxy config - no validator is available
W0126 20:54:01.849607    9619 validation.go:28] Cannot validate kubelet config - no validator is available
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.17.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.17.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.17.2
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.17.2
registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0
registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.5

提前下载好这些镜像

[root@JD1 ~]# kubeadm config images pull --config kubeadm.yaml
W0126 19:44:46.987395   27714 validation.go:28] Cannot validate kube-proxy config - no validator is available
W0126 19:44:46.987429   27714 validation.go:28] Cannot validate kubelet config - no validator is available
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.17.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.17.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.17.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.17.2
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.5

初始化master节点

[root@JD1 ~]# kubeadm init --config kubeadm.yaml
W0126 20:57:30.795523   10460 validation.go:28] Cannot validate kube-proxy config - no validator is available
W0126 20:57:30.795570   10460 validation.go:28] Cannot validate kubelet config - no validator is available
[init] Using Kubernetes version: v1.17.2
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [jd1 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.0.3]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [jd1 localhost] and IPs [10.0.0.3 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [jd1 localhost] and IPs [10.0.0.3 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
W0126 20:57:34.329698   10460 manifests.go:214] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0126 20:57:34.330430   10460 manifests.go:214] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 15.001757 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.17" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node jd1 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node jd1 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: abcdef.0123456789abcdef
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 10.0.0.3:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:2957de566c5bcf9bee9fb2211d1bf0d9cb85eeefb2c5eed35443390728e45957

配置常规用户

[root@JD1 ~]# mkdir -p $HOME/.kube
[root@JD1 ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@JD1 ~]# chown $(id -u):$(id -g) $HOME/.kube/config

查看集群状态

[root@JD1 ~]# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok
controller-manager   Healthy   ok
etcd-0               Healthy   {"health":"true"}

安装Pod Network

接下来安装flannel network add-on

[root@JD1 ~]# mkdir -p ~/k8s/
[root@JD1 ~]# cd ~/k8s
[root@JD1 k8s]# curl -O https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 14416  100 14416    0     0   6772      0  0:00:02  0:00:02 --:--:--  6774
[root@JD1 k8s]# ls
kube-flannel.yml
[root@JD1 k8s]# kubectl apply -f  kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds-amd64 created
daemonset.apps/kube-flannel-ds-arm64 created
daemonset.apps/kube-flannel-ds-arm created
daemonset.apps/kube-flannel-ds-ppc64le created
daemonset.apps/kube-flannel-ds-s390x created

添加worker节点至集群

在另外两台机器上执行如下命令即可

[root@JD3 ~]# kubeadm join 10.0.0.3:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:2957de566c5bcf9bee9fb2211d1bf0d9cb85eeefb2c5eed35443390728e45957

W0126 21:15:58.144981    6559 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.17" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

查看节点信息

在master节点查看

[root@JD1 ~]# kubectl get nodes
NAME   STATUS   ROLES    AGE     VERSION
jd1    Ready    master   19m     v1.17.2
jd2    Ready    <none>   9m55s   v1.17.2
jd3    Ready    <none>   105s    v1.17.2

查看集群状态信息

[root@JD1 ~]# kubectl cluster-info
Kubernetes master is running at https://10.0.0.3:6443
KubeDNS is running at https://10.0.0.3:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

查看k8s集群server端与client端的版本信息

[root@JD1 ~]# kubectl version --short=true
Client Version: v1.17.2
Server Version: v1.17.2

拷贝admin.conf到worker节点

worker节点运行kubectl命令报错

The connection to the server localhost:8080 was refused - did you specify the right host or port?

kubectl命令需要使用kubernetes-admin来运行,将主节点中的/etc/kubernetes/admin.conf文件拷贝到worker节点相同目录下

[root@JD2 ~]# scp root@jd1:/etc/kubernetes/admin.conf /etc/kubernetes/

然后执行

[root@JD2 ~]# mkdir -p $HOME/.kube
[root@JD2 ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@JD2 ~]# chown $(id -u):$(id -g) $HOME/.kube/config

jd3主机也作同样操作,再次执行kubectl命令查看

# 检查nodes
[root@JD2 ~]# kubectl get nodes
NAME   STATUS   ROLES    AGE   VERSION
jd1    Ready    master   63m   v1.17.2
jd2    Ready    <none>   52m   v1.17.2
jd3    Ready    <none>   52m   v1.17.2

# 检查pods
[root@JD2 ~]# kubectl get pods -A
NAMESPACE              NAME                                         READY   STATUS    RESTARTS   AGE
kube-system            coredns-7f9c544f75-hc954                     1/1     Running   0          64m
kube-system            coredns-7f9c544f75-nlrkx                     1/1     Running   0          64m
kube-system            etcd-jd1                                     1/1     Running   0          64m
kube-system            kube-apiserver-jd1                           1/1     Running   0          64m
kube-system            kube-controller-manager-jd1                  1/1     Running   0          64m
kube-system            kube-flannel-ds-amd64-27b72                  1/1     Running   0          57m
kube-system            kube-flannel-ds-amd64-27l7c                  1/1     Running   0          53m
kube-system            kube-flannel-ds-amd64-7bg5p                  1/1     Running   0          53m
kube-system            kube-proxy-44698                             1/1     Running   0          53m
kube-system            kube-proxy-flx2c                             1/1     Running   0          64m
kube-system            kube-proxy-kk2nd                             1/1     Running   0          53m
kube-system            kube-scheduler-jd1                           1/1     Running   0          64m
kubernetes-dashboard   dashboard-metrics-scraper-7b64584c5c-jwmhv   1/1     Running   0          47m
kubernetes-dashboard   kubernetes-dashboard-566f567dc7-ktdpf        1/1     Running   0          47m