實操kubeadm安裝部署Kubernetes集羣全過程 V1.18.0

首先感謝王躍輝我輝哥提供的技術支持，嘿嘿！

準備工具：VMware(已經啓動好三臺Linux服務器Centos7.5及以上)，遠程連接工具putty，xshell等

如果還沒有安裝虛擬機，或者不知道怎麼操作，請移步這裏：

https://blog.csdn.net/ma726518972/article/details/106250012

注意：服務器至少是兩核，如不是，可以通過編輯虛擬機設置。

所有主機配置如下

IP地址	主機名	節點角色	K8S版本	安裝方式
192.168.218.131	k8smaster	master	V1.18.0	kubeadm
192.168.218.132	k8snode1	node1	V1.18.0	kubeadm
192.168.218.133	k8snode2	node2	V1.18.0	kubeadm

 建議先配置完Master服務器，再配置node服務器。

第一步：環境配置

1.1修改主機名（所有服務器都執行）

hostnamectl set-hostname k8smaster

1.2配置hosts解析（所有服務器都執行）

cp /etc/hosts /etc/hosts.bak`date +%F`

cat >> /etc/hosts <<'EOF'
192.168.218.131  k8smaster
192.168.218.132  k8snode1
192.168.218.133  k8snode2
EOF

1.3關閉防火牆（所有服務器都執行）

# 關閉 firewalld 防火牆（允許 master 和 node 的網絡通信）

systemctl stop firewalld
systemctl disable firewalld
systemctl status firewalld

1.4關閉 SElinux 安全模組（所有服務器都執行）

# 關閉 SElinux 安全模組（讓容器可以讀取主機的文件系統）

setenforce 0
sed -i.bak`date +%F` 's|SELINUX=.*|SELINUX=disabled|g' /etc/selinux/config

1.5關閉 Swap 交換分區（所有服務器都執行）

# 關閉 Swap 交換分區（啓用了 Swap，則 Qos 策略可能會失效）

swapoff -a && sed -i.bak "s/\/dev\/mapper\/centos-swap/\#\/dev\/mapper\/centos-swap/g" /etc/fstab

1.6修改阿里的 yum 源（所有服務器都執行）

# 配置阿里的yum源 
# 一下順序不能錯
# 安裝wget命令

yum install -y wget

mkdir -p /etc/yum.repos.d/bak`date +%F` && yes|mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak`date +%F`

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.cloud.tencent.com/repo/centos7_base.repo

wget -O /etc/yum.repos.d/epel.repo http://mirrors.cloud.tencent.com/repo/epel-7.repo

cat > /etc/yum.repos.d/kubernetes.repo <<EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

yum clean all && yum makecache fast

1.7安裝docker容器（所有服務器都執行）

## Install required packages.

yum install -y yum-utils device-mapper-persistent-data lvm2

## Add Docker repository.

yum-config-manager --add-repo \
  https://download.docker.com/linux/centos/docker-ce.repo

## Install Docker CE.

yum update -y && yum install -y \
  containerd.io-1.2.10 \
  docker-ce-19.03.4 \
  docker-ce-cli-19.03.4

## Create /etc/docker directory.

 mkdir -p /etc/docker

# Setup daemon.

cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}
EOF

mkdir -p /etc/systemd/system/docker.service.d

# Restart Docker

systemctl daemon-reload
systemctl restart docker

第二步：安裝kubeadm

2.1安裝 Kubeadm 和相關工具（所有服務器都執行）

yum list|egrep 'kubelet|kubeadm|kubectl'

# 注：kubectl僅僅是個二進制文件而已即 /usr/bin/kubectl

yum install -y kubelet kubeadm kubectl

# 啓動 Kubelet

systemctl start kubelet && systemctl enable kubelet

 #查看kubelet狀態

systemctl status kubelet

運行 systemctl status kubelet 發現kubelet服務啓動失敗，錯誤代碼255。
kubelet.service: main process exited, code=exited, status=255/n/a
​
後來查了資料，運行 journalctl -xefu kubelet 命令查看systemd日誌才發現，真正的錯誤是：
unable to load client CA file /etc/kubernetes/pki/ca.crt: open /etc/kubernetes/pki/ca.crt: no such file or directory
​
這個錯誤在運行kubeadm init 生成CA證書後會被自動解決，此處可先忽略。
再回過頭來看Kubernets官方文檔，其實裏面已經寫了很清楚了：
​
The kubelet is now restarting every few seconds, as it waits in a crashloop for kubeadm to tell it what to do. This crashloop is expected and normal, please proceed with the next step and the kubelet will start running normally.
​
簡單地說就是在kubeadm init 之前kubelet會不斷重啓。

第三步：創建 Kubernetes 集羣

3.1初始化 Master 節點（在Master服務器）

# 注1：版本要根據實際的來更改，我安裝的是K8S 1.18.2，所以改成了 --kubernetes-version=v1.18.2
# 注2：pod-network-cidr我將會用Flannel 所以改爲了 --pod-network-cidr=10.244.0.0/16

kubeadm init --kubernetes-version=v1.18.2 \
--pod-network-cidr=10.244.0.0/16 \
--image-repository=registry.cn-hangzhou.aliyuncs.com/google_containers

 # 大約一分鐘
# 輸出以下內容表示成功：....................  中間日誌省略，最後的日誌如下   ...........................

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 192.168.218.131:6443 --token yptahz.1rm8nbkg1frzbhlh \
    --discovery-token-ca-cert-hash sha256:dc7ebc35051b0ee8c6dcb8f12f2fc8b61766cef8960210c839ea51e722e6a26c

#  上面一句是 Node 節點加入集羣的命令，記得保存一下，而且token的有效期是24小時，如果過期了，使用kubeadm token create再生成一個token
#  上面過程中生成的配置文件在  /var/lib/kubelet/config.yaml

3.2在master上操作，拷貝上面的命令（在Master服務器）

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

 # 打印文件看一下內容

[root@localhost ~]# cat $HOME/.kube/config
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: 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
    server: https://192.168.218.131:6443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: kubernetes-admin
  name: kubernetes-admin@kubernetes
current-context: kubernetes-admin@kubernetes
kind: Config
preferences: {}
users:
- name: kubernetes-admin
  user:
    client-certificate-data: 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
    client-key-data: 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

3.3安裝flanneld（在master服務器上）

只在master節點安裝flanneld即可，其它節點會自動安裝的flannel pod，多少節點多少個flannel pod

# 如果不好下載多試兩次，也可以用瀏覽器下載工具下來，然後再傳到服務器

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

#  因爲kube-flannel.yml文件中使用的鏡像爲quay.io的，國內無法拉取，所以同樣的先從國內源quay.azk8s.cn或quay-mirror.qiniu.com上下載。

grep 'quay.io/coreos' kube-flannel.yml

[root@localhost ~]# grep 'quay.io/coreos' kube-flannel.yml
        image: quay.io/coreos/flannel:v0.12.0-amd64
        image: quay.io/coreos/flannel:v0.12.0-amd64
        image: quay.io/coreos/flannel:v0.12.0-arm64
        image: quay.io/coreos/flannel:v0.12.0-arm64
        image: quay.io/coreos/flannel:v0.12.0-arm
        image: quay.io/coreos/flannel:v0.12.0-arm
        image: quay.io/coreos/flannel:v0.12.0-ppc64le
        image: quay.io/coreos/flannel:v0.12.0-ppc64le
        image: quay.io/coreos/flannel:v0.12.0-s390x
        image: quay.io/coreos/flannel:v0.12.0-s390x

sed -i.bak`date +%F` '[email protected]/[email protected]/coreos@g' kube-flannel.yml

kubectl apply -f kube-flannel.yml

flanneld默認安裝在kube-system Namespace中，使用以下命令查看:

kubectl -n kube-system get pods

[root@localhost ~]# kubectl -n kube-system get pods
NAME                                READY   STATUS                  RESTARTS   AGE
coredns-546565776c-pp6gr            0/1     Pending                 0          29m
coredns-546565776c-r644s            0/1     Pending                 0          29m
etcd-k8smaster                      1/1     Running                 0          29m
kube-apiserver-k8smaster            1/1     Running                 0          29m
kube-controller-manager-k8smaster   1/1     Running                 0          29m
kube-flannel-ds-amd64-hml7j         0/1     Init:ImagePullBackOff   0          15m
kube-proxy-gfzgb                    1/1     Running                 0          29m
kube-scheduler-k8smaster            1/1     Running                 0          29m

3.添加節點（節點服務器執行，master服務器不執行）

添加 node 節點,執行如下命令，使所有 node 節點加入 Kubernetes 集羣；

# 使用上面master初始化成功時所打印的命令

kubeadm token create  # 由於token過期了，主節點再重新生成一個，如果沒有過期則不用執行此命令

# 在 所有 node 節點都執行如下的命令，如下命令就是主節點在初始化成功時的日誌中的命令，直接複製上面初始化時的命令即可 

# 這裏的192.168.218.131是主節點的IP

kubeadm join 192.168.218.131:6443 --token yptahz.1rm8nbkg1frzbhlh \
    --discovery-token-ca-cert-hash sha256:dc7ebc35051b0ee8c6dcb8f12f2fc8b61766cef8960210c839ea51e722e6a26c
​
----------------------- 日誌輸出如下，則加入成功--------------------------------

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

第四步：查看所有節點

在Master服務器上執行

 kubectl get nodes

恭喜你！成功完成Kubernetes集羣的搭建，點個贊再走吧！

（有問題可評論留言，不定時解答）