kubeadm是Kubernetes官方提供的用于快速安装 Kubernetes 集群的工具，通过将集群的各个组件进行容器化安装管理，通过kubeadm的方式安装集群比二进制的方式安装要方便
这里先申明一点，本环境最重要的是能够拉取国外镜像，如无法拉取国外镜像请绕道。
环境
地域：中国香港一区
配置：2 核 4 GB 1 Mbps
系统盘：普通云硬盘
系统： CentOS 7.5 64位
vpc信息：
vpc cidr：10.0.0.0/16
子网：10.0.0.0/24
先创建vpc
创建私有网络
1. 创建cvm
这里创建两台cvm，一台master、一台node此步不赘述请按需配置
2. 基础环境配置主机名
代码语言：txt复制#master 10.0.0.15
hostnamectl set-hostname kube-master
#配置node 的hostname
hostnamectl set-hostname kube-node
# 停防火墙
systemctl stop firewalld
systemctl disable firewalld其他配置
#关闭Swap
swapoff -a
sed -i 's/.\*swap.\*/#&/' /etc/fstab
#关闭Selinux
setenforce 0
sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/sysconfig/selinux
sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
sed -i "s/^SELINUX=permissive/SELINUX=disabled/g" /etc/sysconfig/selinux
sed -i "s/^SELINUX=permissive/SELINUX=disabled/g" /etc/selinux/config
#加载br_netfilter
modprobe br_netfilter
#添加配置内核参数
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
#加载配置
sysctl -p /etc/sysctl.d/k8s.conf3. 安装docker
对于版本的选择，官方有个支持列表：
The list of validated docker versions remain unchanged at 1.11.1, 1.12.1, 1.13.1, 17.03, 17.06, 17.09, 18.06 since （https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.13.md#external-dependencies）
这里我安装的是最新的，如果你在根据本文档搭建，可以通过查看版本，指定版本安装，如果不加版本直接yum install 默认是最新的版本。
代码语言：txt复制sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
sudo yum install -y docker-ce
systemctl start docker && systemctl enable docker查看docker版本
代码语言：txt复制$ docker version
Client:
Version: 18.09.4
API version: 1.39
Go version: go1.10.8
Git commit: d14af54266
Built: Wed Mar 27 18:34:51 2019
OS/Arch: linux/amd64
Experimental: false
Server: Docker Engine - Community
Engine:
Version: 18.09.4
API version: 1.39 (minimum version 1.12)
Go version: go1.10.8
Git commit: d14af54
Built: Wed Mar 27 18:04:46 2019
OS/Arch: linux/amd64
Experimental: false4. 安装kubeadm，kubelet，kubectl
这里如果不指定默认也是安装最新的
代码语言：txt复制$ cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-$basearch
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
$ yum install -y kubelet kubeadm kubectl
$ systemctl enable kubelet && systemctl start kubelet5. 下载所需的master组件镜像
--kubernetes-version v1.14.0 指定k8s版本
代码语言：txt复制$ kubeadm config images pull --kubernetes-version v1.14.0
config/images Pulled k8s.gcr.io/kube-apiserver:v1.14.0
config/images Pulled k8s.gcr.io/kube-controller-manager:v1.14.0
config/images Pulled k8s.gcr.io/kube-scheduler:v1.14.0
config/images Pulled k8s.gcr.io/kube-proxy:v1.14.0
config/images Pulled k8s.gcr.io/pause:3.1
config/images Pulled k8s.gcr.io/etcd:3.3.10
config/images Pulled k8s.gcr.io/coredns:1.3.1
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-proxy v1.14.0 5cd54e388aba 6 days ago 82.1MB
k8s.gcr.io/kube-apiserver v1.14.0 ecf910f40d6e 6 days ago 210MB
k8s.gcr.io/kube-controller-manager v1.14.0 b95b1efa0436 6 days ago 158MB
k8s.gcr.io/kube-scheduler v1.14.0 00638a24688b 6 days ago 81.6MB
k8s.gcr.io/coredns 1.3.1 eb516548c180 2 months ago 40.3MB
k8s.gcr.io/etcd 3.3.10 2c4adeb21b4f 4 months ago 258MB
k8s.gcr.io/pause 3.1 da86e6ba6ca1 15 months ago 742kB6. 初始化master
kebeadm init需要加上参数 详细的参数介绍可看：https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-init/
代码语言：txt复制$ kubeadm init --apiserver-advertise-address=10.0.0.15 --kubernetes-version=v1.14.0 --pod-network-cidr=172.16.0.0/16
[init] Using Kubernetes version: v1.14.0
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[WARNING Hostname]: hostname "kube-master" could not be reached
[WARNING Hostname]: hostname "kube-master": lookup kube-master on 183.60.83.19:53: no such host
[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] Activating the kubelet service
[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 [kube-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.0.15]
[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/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [kube-master localhost] and IPs [10.0.0.15 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [kube-master localhost] and IPs [10.0.0.15 127.0.0.1 ::1]
[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"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[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 18.502803 seconds
[upload-config] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.14" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --experimental-upload-certs
[mark-control-plane] Marking the node kube-master as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node kube-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 63lvgx.obnzzp2auuecvgno
[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
[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 10.0.0.15:6443 --token 63lvgx.obnzzp2auuecvgno
--discovery-token-ca-cert-hash sha256:e15bdd9c102ecb3ae4213c75e90f908cddbf4e3bee8a085f1d06bf6cfb1278ca 7. 配置常规用户如何使用kubectl访问集群
代码语言：txt复制 mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config8. 安装Flannel
代码语言：txt复制kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml9. 查看所有pod
代码语言：txt复制$ kubectl get pod -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-fb8b8dccf-dh8r2 1/1 Running 0 4m21s
coredns-fb8b8dccf-djf7p 1/1 Running 0 4m21s
etcd-kube-master 1/1 Running 0 3m38s
kube-apiserver-kube-master 1/1 Running 0 3m18s
kube-controller-manager-kube-master 1/1 Running 0 3m20s
kube-flannel-ds-amd64-69jzk 1/1 Running 0 96s
kube-proxy-fhhp9 1/1 Running 0 4m21s
kube-scheduler-kube-master 1/1 Running 0 3m24s10.查看节点
代码语言：txt复制 $ kubectl get node
NAME STATUS ROLES AGE VERSION
kube-master Ready master 21h v1.14.011.加入node节点
执行上述1-5步骤
然后执行初始化master时底下的 kubeadm join信息
代码语言：txt复制[root@VM_0_10_centos etc]# kubeadm join 10.0.0.15:6443 --token 63lvgx.obnzzp2auuecvgno
> --discovery-token-ca-cert-hash sha256:e15bdd9c102ecb3ae4213c75e90f908cddbf4e3bee8a085f1d06bf6cfb1278ca
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[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-1.14" 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] Activating the kubelet service
[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.返回master节点用watch kubectl get nodes查看节点，看到node变成ready即代表成功
12.创建一个nginx
代码语言：txt复制$ cat my-nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: my-nginx
spec:
selector:
matchLabels:
run: my-nginx
replicas: 2
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: nginx
ports:
- containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: my-nginx
labels:
run: my-nginx
spec:
ports:
- nodePort: 31250
port: 80
protocol: TCP
targetPort: 80
selector:
run: my-nginx
type: NodePort保存好yaml文件后通过kubectl create -f my-nginx.yaml 创建
代码语言：txt复制$ kubectl create -f my-nginx.yaml
deployment.apps/my-nginx created
service/my-nginx created查看创建出来的pod和service
代码语言：txt复制$ kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
my-nginx-86459cfc9f-sppzq 1/1 Running 0 3m40s 172.16.1.16 kube-node1 <none> <none>
my-nginx-86459cfc9f-zjcp7 1/1 Running 0 3m40s 172.16.1.17 kube-node1 <none> <none>
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 114m
my-nginx NodePort 10.98.233.226 <none> 80:31524/TCP 3m43s通过 curl 10.0.0.10:31524获取nginx内容
代码语言：txt复制$ curl 10.0.0.10:31524
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>能正常获取内容即代表正常。
