Kubernetes探索學習001--Centos7.6使用kubeadm快速部署Kubernetes集羣

時間 2020-05-08

標籤 kubernetes 探索學習 centos7.6 centos 使用 kubeadm 快速部署集羣欄目 CentOS 简体版

原文原文鏈接

#####1.2.1.確認系統版本，修改主機名node

1.查看系統版本
[root@iZ2ze7ftggknd1fplnxygqZ ~]# cat /etc/redhat-release 
CentOS Linux release 7.6.1810 (Core)
2.修改主機名
hostnamectl set-hostname kubernetes01
3.別忘了修改/etc/hosts文件
[root@kubernetes01 ~]# cat /etc/hosts
127.0.0.1       localhost       localhost.localdomain   localhost4      localhost4.localdomain4
::1     localhost       localhost.localdomain   localhost6      localhost6.localdomain6
# kubernetes-cluster
10.5.0.206 kubernetes01
...

#####1.2.2.關閉防火牆linux

systemctl stop firewalld && systemctl disable firewalld

#####1.2.3.檢查selinux是否關閉git

[root@kubernetes01 ~]# setenforce 0
setenforce: SELinux is disabled

#####1.2.4.提早處理路由問題github

cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1    
vm.swappiness=0
EOF
以後
sysctl --system

#####1.2.5.安裝docker-ce, 注意docker-ce的版本和kubernetes版本的兼容性！docker

使用yum安裝docekr-ce，版本v18.06.1
[root@kubernetes01 ~]# yum -y install yum-utils device-mapper-persistent-data lvm2
[root@kubernetes01 ~]# yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
[root@kubernetes01 ~]# yum -y install docker-ce-18.06.1.ce
[root@kubernetes01 ~]# /bin/systemctl start docker.service 
[root@kubernetes01 ~]# docker --version 
Docker version 18.06.1-ce, build e68fc7a

#####1.2.6.安裝kubelet kubeadm kubectlshell

1.配置某雲的yum源
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
EOF
2.安裝key文件
wget https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
rpm -import rpm-package-key.gpg
3.yum安裝
yum install -y kubelet-1.12.1
yum install -y kubectl-1.12.1
yum install -y kubeadm-1.12.1

#####1.2.7.版本檢查bootstrap

[root@kubernetes01 ~]# kubelet --version
Kubernetes v1.12.1
[root@kubernetes01 ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"12", GitVersion:"v1.12.1", GitCommit:"4ed3216f3ec431b140b1d899130a69fc671678f4", GitTreeState:"clean", BuildDate:"2018-10-05T16:46:06Z", GoVersion:"go1.10.4", Compiler:"gc", Platform:"linux/amd64"}
The connection to the server localhost:8080 was refused - did you specify the right host or port?
[root@kubernetes01 ~]# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"12", GitVersion:"v1.12.1", GitCommit:"4ed3216f3ec431b140b1d899130a69fc671678f4", GitTreeState:"clean", BuildDate:"2018-10-05T16:43:08Z", GoVersion:"go1.10.4", Compiler:"gc", Platform:"linux/amd64"}

v1.12.1kubeadm須要的kubernetes組件docker鏡像版本:
k8s.gcr.io/kube-apiserver:v1.12.1
k8s.gcr.io/kube-controller-manager:v1.12.1
k8s.gcr.io/kube-scheduler:v1.12.1
k8s.gcr.io/kube-proxy:v1.12.1
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.2.24
k8s.gcr.io/coredns:1.2.2

#####1.2.8.下載kubernetes相關組件的docker鏡像centos

因爲國內網絡環境的「特殊性」，這裏另闢蹊徑。
[root@kubernetes01 ~]# cat pull_k8s_images.sh 
#!/bin/bash
images=(kube-proxy:v1.12.1 kube-scheduler:v1.12.1 kube-controller-manager:v1.12.1
kube-apiserver:v1.12.1
etcd:3.2.24 coredns:1.2.2 pause:3.1 )
for imageName in ${images[@]} ; do
docker pull anjia0532/google-containers.${imageName}
docker tag anjia0532/google-containers.$imageName k8s.gcr.io/$imageName
docker rmi anjia0532/google-containers.$imageName
done

#####1.2.9.查看鏡像信息api

各位還記得開頭提起過的scheduler,controller-manager,apiserver這三個基本組件的做用嗎？😂別忘記～～
[root@kubernetes01 ~]# docker images
REPOSITORY                           TAG                 IMAGE ID            CREATED             SIZE
k8s.gcr.io/kube-proxy                v1.12.1             61afff57f010        5 months ago        96.6MB
k8s.gcr.io/kube-apiserver            v1.12.1             dcb029b5e3ad        5 months ago        194MB
k8s.gcr.io/kube-scheduler            v1.12.1             d773ad20fd80        5 months ago        58.3MB
k8s.gcr.io/kube-controller-manager   v1.12.1             aa2dd57c7329        5 months ago        164MB
k8s.gcr.io/etcd                      3.2.24              3cab8e1b9802        6 months ago        220MB
k8s.gcr.io/coredns                   1.2.2               367cdc8433a4        7 months ago        39.2MB
k8s.gcr.io/pause                     3.1                 da86e6ba6ca1        15 months ago       742kB

#####1.2.10.使用kubeadm部署kubernetes集羣master節點

[root@kubernetes01 ~]# kubeadm init --kubernetes-version=v1.12.1 
preflight檢測沒有問題後通過一段時間，看到這樣的提示算是完成了對Kubernetes Master節點的部署。
Your Kubernetes master 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/

You can now join any number of machines by running the following on each node
as root:

  kubeadm join 10.5.0.206:6443 --token bh3pih.cuir6xpjl7zn7pf2 --discovery-token-ca-cert-hash sha256:ae00fc1ad4a680c01be4deaae6f6e4cf554867664bc5c16e0b3f98d4f2adcf2c

在開始使用以前，須要以常規用戶身份運行如下命令: 上面那段英文中有說明！
由於Kubernetes集羣默認是須要加密訪問的！
so執行👇
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

#####1.2.11.健康檢查

1.查看主要組件的健康狀態
[root@kubernetes01 ~]# kubectl get cs
NAME                 STATUS    MESSAGE              ERROR
scheduler            Healthy   ok                   
controller-manager   Healthy   ok                   
etcd-0               Healthy   {"health": "true"}   
2.查看master節點狀態
[root@kubernetes01 ~]# kubectl get nodes
NAME           STATUS     ROLES    AGE     VERSION
kubernetes01   NotReady   master   4m15s   v1.12.1

#####1.2.12.部署網絡插件weave

[root@kubernetes01 ~]# kubectl apply -f https://git.io/weave-kube-1.6
serviceaccount/weave-net created
serviceaccount/weave-net created
clusterrole.rbac.authorization.k8s.io/weave-net created
clusterrolebinding.rbac.authorization.k8s.io/weave-net created
role.rbac.authorization.k8s.io/weave-net created
rolebinding.rbac.authorization.k8s.io/weave-net created
daemonset.extensions/weave-net created
等一下子，查看Master節點狀態，STATUS已經變了，這是由於部署的網絡組件生效了
[root@kubernetes01 ~]# kubectl get nodes
NAME                STATUS   ROLES    AGE   VERSION
kubernetes-master   Ready    master   21m   v1.12.1

#####1.2.13查看Master節點上網絡weave相關Pod的狀態

[root@kubernetes01 ~]# kubectl get pods -n kube-system -l name=weave-net -o wide
NAME              READY   STATUS    RESTARTS   AGE     IP           NODE                NOMINATED NODE
weave-net-vhs56   2/2     Running   0          6m59s   10.5.0.206   kubernetes-master   <none>

#####1.2.14部署可視化插件

1.獲取可視化插件docker鏡像，修改tag
docker pull anjia0532/google-containers.kubernetes-dashboard-amd64:v1.10.0
docker tag  anjia0532/google-containers.kubernetes-dashboard-amd64:v1.10.0   k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.1
docker rmi  anjia0532/google-containers.kubernetes-dashboard-amd64:v1.10.0 
2.獲取並修改可視化插件YAML文件的最後部分，便於後期經過token登錄可視化頁面，這裏須要特別注意的是暴露了30001端口，這若是在生產環境是極不安全的！
[root@kubernetes01 ~]# wget https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml
[root@kubernetes01 ~]# tail -n 20 kubernetes-dashboard.yaml
        effect: NoSchedule

---
# ------------------- Dashboard Service ------------------- #

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  selector:
    k8s-app: kubernetes-dashboard
3.部署可視化插件
[root@kubernetes01 ~]# kubectl apply -f kubernetes-dashboard.yaml
secret/kubernetes-dashboard-certs created
serviceaccount/kubernetes-dashboard created
role.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
deployment.apps/kubernetes-dashboard created
service/kubernetes-dashboard configured
4.查看可視化插件對應的Pod狀態
[root@kubernetes01 ~]# kubectl get pods -n kube-system |  grep dash
kubernetes-dashboard-65c76f6c97-f29nm   1/1     Running   0          3m8s
5.獲取token值
[root@kubernetes01 ~]# kubectl -n kube-system describe $(kubectl -n kube-system get secret -n kube-system -o name | grep namespace) | grep token
Name:         namespace-controller-token-mt4sh
Type:  kubernetes.io/service-account-token
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.W2flckBO8CrzGyJzw2aJH5obQSjy4PNSll7uHOiIXPk4dnOTEzI-BfM4C9QrNDjbNTu8gIdLHntLj1181Sf_sRMidB_vhUPg6CFA1zy3XmYH21eVqjSxEBNXMSfrJHBgXnBzaHieaXqF55_etABB0j4xLM7V-bRsQ9AB0G3cv1IYU_gYG3BozksvAObmDEY4GgCI7f0-nu2YRqOMPJPhXWzKOGUvBBPyj171Xo06QvF6p9zpTMSoLa3aV-gU4XA2nMf2_aDdgFrGVI4p95ziewyu0o-W-DiEnXW1hRtwgg-PRe3QPU9ps3TALlr3U8rwh3xVmlqnRuNGVDqzmclVdQ
訪問https://10.5.0.206:30001經過token登錄控制面板,注意是https協議！

#####1.2.15部署容器存儲插件這裏須要知道Rook項目是基於Ceph的Kubernetes存儲插件，一個可用於生產級別的作持久化存儲的插件，值得好好把玩。

cd /usr/local/src
yum -y install git
git clone https://github.com/rook/rook.git
cd /usr/local/src/rook/cluster/examples/kubernetes/ceph
kubectl apply -f operator.yaml
kubectl apply -f cluster.yaml

####1.3.Worker節點

和安裝Master節點類似，首先把準備工做作好，主機名修改，關閉防火牆，提早處理路由問題，配置yum源等等，因爲節點數9個，因此這裏簡單的使用了下ansible playbook配合shell腳本進行安裝，節省時間。
1.docker-ce的安裝腳本
cat install_dockerce.sh 
#!/bin/bash
yum -y install yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum -y install docker-ce-18.06.1.ce
2.kubernetes相關組件的安裝腳本
cat install_kubectl.sh
#!/bin/bash
# install kubelet and kubeadm and kubectls
yum install -y kubelet-1.12.1
yum install -y kubectl-1.12.1
yum install -y kubeadm-1.12.1
# install kube-proxy and pause
images=(kube-proxy:v1.12.1 pause:3.1 )
for imageName in ${images[@]} ; do
docker pull anjia0532/google-containers.$imageName
docker tag anjia0532/google-containers.$imageName k8s.gcr.io/$imageName
docker rmi anjia0532/google-containers.$imageName
done
# join cluster
kubeadm join 10.5.0.206:6443 --token bh3pih.cuir6xpjl7zn7pf2 --discovery-token-ca-cert-hash sha256:ae00fc1ad4a680c01be4deaae6f6e4cf554867664bc5c16e0b3f98d4f2adcf2c

####1.4其它

遇到的一些小問題:
kubeadmv1.12.1沒法正確安裝的問題，節點報錯[ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]:的問題，從k8s.gcr.io拉取鏡像失敗的問題，這些問題都很好解決,卡住了別怕！一點一點兒克服困難。

####1.5總結文章中使用kubeadm部署了1臺Kubernetes Master節點，部署了9臺Kubernetes Worker節點，部署了可視化插件，部署了容器存儲插件，部署了容器的網絡插件。總的來講kubeadm是玩起來是至關方便😄，可是缺點也顯而易見，好比沒有作到Master的高可用，安全性不足等等等😭...so並不具有生產環境使用的標準。這裏我的推薦生產環境研究使用kubeasz和kubespray部署！最後的最後，學習kubernetes須要的就是探索精神！☀️ PS:服務器使用的是國內某☁️的機器歡迎你們留言討論哦～～～