使用kubeadm部署k8s集群[v1.18.0]

使用kubeadm部署k8s集群

环境

IP地址	主机名	节点
10.0.0.63	k8s-master1	master1
10.0.0.65	k8s-node1	node1
10.0.0.66	k8s-node2	node2

1. 简要

kubeadm是官方社区推出的快速部署kubernetes集群工具

部署环境适用于学习和使用k8s相关软件和功能

2. 安装要求

3台纯净centos虚拟机,版本为7.x及以上
机器配置 2核4G以上 x3台
服务器网络互通
禁止swap分区

3. 学习目标

学会使用kubeadm来安装一个集群,便于学习k8s相关知识

4. 环境准备

# 1. 关闭防火墙功能
systemctl stop firewalld
systemctl disable firewalld

# 2.关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0

# 3. 关闭swap
swapoff -a
#或将命令加入开机启动
echo "swapoff -a" >>/etc/profile
source /etc/profile

# 4. 服务器规划
cat > /etc/hosts << EOF
10.0.0.63 k8s-master1
10.0.0.65 k8s-node1
10.0.0.66 k8s-node2
EOF

#5. 临时主机名配置方法:
 hostnamectl set-hostname  k8s-master1
 bash

#6. 时间同步配置
yum install -y ntpdate
ntpdate time.windows.com

#开启转发
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

#7. 时间同步
echo '*/5 * * * * /usr/sbin/ntpdate -u ntp.api.bz' >>/var/spool/cron/root
systemctl restart crond.service
crontab -l
# 以上可以全部复制粘贴直接运行,但是主机名配置需要重新修改

5. docker安装[所有节点都需要安装]

#源添加
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
wget -P /etc/yum.repos.d/ http://mirrors.aliyun.com/repo/epel-7.repo
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
yum clean all
yum install -y bash-completion.noarch

# 安装指定版版本
yum -y install docker-ce-18.09.9-3.el7

#也可以查看版本安装
yum list docker-ce --showduplicates | sort -r

#启动docker
systemctl enable docker
systemctl start docker
systemctl status docker

6. docker配置cgroup驱动[所有节点]

rm -f /etc/docker/*
sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://ajvcw8qn.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

  拉取flanel镜像:
  docker pull lizhenliang/flannel:v0.11.0-amd64

7. 镜像加速[所有节点]

curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://f1361db2.m.daocloud.io
systemctl restart docker

#如果源太多容易出错. 错了就删除一个.bak源试试看
#保留 curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://f1361db2.m.daocloud.io

这个是阿里云配置的加速
https://cr.console.aliyun.com/cn-hangzhou/instances/mirrors

8.kubernetes源配置[所有节点]

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

9. 安装kubeadm，kubelet和kubectl[所有节点]

yum install -y kubelet-1.18.0 kubeadm-1.18.0 kubectl-1.18.0
systemctl enable kubelet

10. 部署Kubernetes Master [ master 10.0.0.63]

kubeadm init \
  --apiserver-advertise-address=10.0.0.63 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.18.0 \
  --service-cidr=10.1.0.0/16 \
  --pod-network-cidr=10.244.0.0/16

#成功后加入环境变量:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

初始化后获取到token:

kubeadm join 10.0.0.63:6443 --token 2cdgi6.79j20fhly6xpgfud

--discovery-token-ca-cert-hash sha256:3d847b858ed649244b4110d4d60ffd57f43856f42ca9c22e12ca33946673ccb4

记住token,后面使用

注意:

W0507 00:43:52.681429 3118 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io] [init] Using Kubernetes version: v1.18.0 [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/ error execution phase preflight: [preflight] Some fatal errors occurred: [ERROR NumCPU]: the number of available CPUs 1 is less than the required 2 [preflight] If you know what you are doing, you can make a check non-fatal with --ignore-preflight-errors=... To see the stack trace of this error execute with --v=5 or higher

10.1 报错处理

报错1: 需要修改docker驱动为systemd /etc/docker/daemon.json 文件中加入: "exec-opts": ["native.cgroupdriver=systemd"]

报错2: [ERROR NumCPU]: the number of available CPUs 1 is less than the required 2

出现该报错,是cpu有限制,将cpu修改为2核4G以上配置即可

报错2: 出现该报错,是cpu有限制,将cpu修改为2核4G以上配置即可

报错3: 加入集群出现报错:

W0507 01:19:49.406337   26642 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[preflight] Running pre-flight checks
error execution phase preflight: [preflight] Some fatal errors occurred:
	[ERROR DirAvailable--etc-kubernetes-manifests]: /etc/kubernetes/manifests is not empty
	[ERROR FileAvailable--etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists
	[ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher
[root@k8s-master2 yum.repos.d]# kubeadm join 10.0.0.63:6443 --token q8bfij.fipmsxdgv8sgcyq4 \
>     --discovery-token-ca-cert-hash sha256:26fc15b6e52385074810fdbbd53d1ba23269b39ca2e3ec3bac9376ed807b595c
>     --discovery-token-ca-cert-hash sha256:26fc15b6e52385074810fdbbd53d1ba23269b39ca2e3ec3bac9376ed807b595c
W0507 01:20:26.246981   26853 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[preflight] Running pre-flight checks
error execution phase preflight: [preflight] Some fatal errors occurred:
	[ERROR DirAvailable--etc-kubernetes-manifests]: /etc/kubernetes/manifests is not empty
	[ERROR FileAvailable--etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists
	[ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher

解决办法:
执行: kubeadm reset 重新加入

10.2. kubectl命令工具配置[master]：

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

#获取节点信息
# kubectl get nodes

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS     ROLES    AGE     VERSION
k8s-master1   NotReady   master   2m59s   v1.18.0
k8s-node1     NotReady   <none>   86s     v1.18.0
k8s-node2     NotReady   <none>   85s     v1.18.0

#可以获取到其他主机的状态信息,证明集群完毕,另一台k8s-master2 没有加入到集群中,是因为要做多master,这里就不加了.

10.2. 安装网络插件[master]

[直在master上操作]上传kube-flannel.yaml,并执行:
kubectl apply -f kube-flannel.yaml
kubectl get pods -n kube-system

下载地址:
https://www.chenleilei.net/soft/k8s/kube-flannel.yaml

[必须全部运行起来,否则有问题.]
[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME                                  READY   STATUS    RESTARTS   AGE
coredns-7ff77c879f-5dq4s              1/1     Running   0          13m
coredns-7ff77c879f-v68pc              1/1     Running   0          13m
etcd-k8s-master1                      1/1     Running   0          13m
kube-apiserver-k8s-master1            1/1     Running   0          13m
kube-controller-manager-k8s-master1   1/1     Running   0          13m
kube-flannel-ds-amd64-2ktxw           1/1     Running   0          3m45s
kube-flannel-ds-amd64-fd2cb           1/1     Running   0          3m45s
kube-flannel-ds-amd64-hb2zr           1/1     Running   0          3m45s
kube-proxy-4vt8f                      1/1     Running   0          13m
kube-proxy-5nv5t                      1/1     Running   0          12m
kube-proxy-9fgzh                      1/1     Running   0          12m
kube-scheduler-k8s-master1            1/1     Running   0          13m

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    master   14m   v1.18.0
k8s-node1     Ready    <none>   12m   v1.18.0
k8s-node2     Ready    <none>   12m   v1.18.0

11. 将node1 node2 加入master

node1 node2加入集群配置

在要加入的节点种执行以下命令来加入:
kubeadm join 10.0.0.63:6443 --token fs0uwh.7yuiawec8tov5igh \
    --discovery-token-ca-cert-hash sha256:471442895b5fb77174103553dc13a4b4681203fbff638e055ce244639342701d

#这个配置在安装master的时候有过提示,请注意首先要配置cni网络插件
#加入成功后,master节点检测:
[root@k8s-master1 docker]#  kubectl get nodes
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    master   14m   v1.18.0
k8s-node1     Ready    <none>   12m   v1.18.0
k8s-node2     Ready    <none>   12m   v1.18.0

12 token创建和查询

默认token会保存24消失,过期后就不可用,如果需要重新建立token,可在master节点使用以下命令重新生成:

kubeadm token create
kubeadm token list
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
结果:
3d847b858ed649244b4110d4d60ffd57f43856f42ca9c22e12ca33946673ccb4

新token加入集群方法:
kubeadm join 10.0.0.63:6443 --discovery-token nuja6n.o3jrhsffiqs9swnu --discovery-token-ca-cert-hash 63bca849e0e01691ae14eab449570284f0c3ddeea590f8da988c07fe2729e924

13. 安装dashboard界面

[root@k8s-master1 ~]# kubectl get svc -n kubernetes-dashboard
NAME                        TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)         AGE
dashboard-metrics-scraper   ClusterIP   10.1.94.43     <none>        8000/TCP        7m58s
kubernetes-dashboard        NodePort    10.1.187.162   <none>        443:30001/TCP   7m58s

​

13.1 访问测试

10.0.0.63 10.0.0.64 10.0.0.65 集群任意一个角色访问30001端口都可以访问到dashboard页面.

13.2 获取dashboard token, 也就是创建service account并绑定默认cluster-admin管理员集群角色

# kubectl create serviceaccount dashboard-admin -n kubernetes-dashboard
# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kubernetes-dashboard:dashboard-admin
# kubectl describe secrets -n kubernetes-dashboard $(kubectl -n kubernetes-dashboard get secret | awk '/dashboard-admin/{print $1}')

将复制的token 填写到 上图中的 token选项,并选择token登录

14. 验证集群是否工作正常

验证集群状态是否正常有三个方面:
1. 能否正常部署应用
2. 集群网络是否正常
3. 集群内部dns解析是否正常

14.1 验证部署应用和日志查询

#创建一个nginx应用
kubectl create deployment  k8s-status-checke --image=nginx
#暴露80端口
kubectl expose deployment k8s-status-checke --port=80  --target-port=80 --type=NodePort

#删除这个deployment
kubectl delete deployment k8s-status-checke

#查询日志:
[root@k8s-master1 ~]# kubectl logs -f nginx-f89759699-m5k5z

14.2 验证集群网络是否正常

1. 拿到一个应用地址
[root@k8s-master1 ~]# kubectl get pods -o wide
NAME       READY   STATUS    RESTARTS   AGE   IP            NODE        NOMINATED   READINESS
pod/nginx   1/1    Running   0          25h   10.244.2.18   k8s-node2   <none>      <none>

2. 通过任意节点ping这个应用ip
[root@k8s-node1 ~]# ping 10.244.2.18
PING 10.244.2.18 (10.244.2.18) 56(84) bytes of data.
64 bytes from 10.244.2.18: icmp_seq=1 ttl=63 time=2.63 ms
64 bytes from 10.244.2.18: icmp_seq=2 ttl=63 time=0.515 ms

3. 访问节点
[root@k8s-master1 ~]# curl -I 10.244.2.18
HTTP/1.1 200 OK
Server: nginx/1.17.10
Date: Sun, 10 May 2020 13:19:02 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 14 Apr 2020 14:19:26 GMT
Connection: keep-alive
ETag: "5e95c66e-264"
Accept-Ranges: bytes

4. 查询日志
[root@k8s-master1 ~]# kubectl logs -f nginx
10.244.1.0 - - [10/May/2020:13:14:25 +0000] "GET / HTTP/1.1" 200 612 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36" "-"

14.3 验证集群内部dns解析是否正常

检查DNS:
[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME                                  READY   STATUS    RESTARTS   AGE
coredns-7ff77c879f-5dq4s              1/1     Running   1          4d   #有时dns会出问题
coredns-7ff77c879f-v68pc              1/1     Running   1          4d   #有时dns会出问题
etcd-k8s-master1                      1/1     Running   4          4d
kube-apiserver-k8s-master1            1/1     Running   3          4d
kube-controller-manager-k8s-master1   1/1     Running   3          4d
kube-flannel-ds-amd64-2ktxw           1/1     Running   1          4d
kube-flannel-ds-amd64-fd2cb           1/1     Running   1          4d
kube-flannel-ds-amd64-hb2zr           1/1     Running   4          4d
kube-proxy-4vt8f                      1/1     Running   4          4d
kube-proxy-5nv5t                      1/1     Running   2          4d
kube-proxy-9fgzh                      1/1     Running   2          4d
kube-scheduler-k8s-master1            1/1     Running   4          4d

#有时dns会出问题,解决方法:
1. 导出yaml文件
kubectl get deploy coredns -n kube-system -o yaml >coredns.yaml
2. 删除coredons
kubectl delete -f coredns.yaml

检查:
[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME                                  READY   STATUS    RESTARTS   AGE
etcd-k8s-master1                      1/1     Running   4          4d
kube-apiserver-k8s-master1            1/1     Running   3          4d
kube-controller-manager-k8s-master1   1/1     Running   3          4d
kube-flannel-ds-amd64-2ktxw           1/1     Running   1          4d
kube-flannel-ds-amd64-fd2cb           1/1     Running   1          4d
kube-flannel-ds-amd64-hb2zr           1/1     Running   4          4d
kube-proxy-4vt8f                      1/1     Running   4          4d
kube-proxy-5nv5t                      1/1     Running   2          4d
kube-proxy-9fgzh                      1/1     Running   2          4d
kube-scheduler-k8s-master1            1/1     Running   4          4d

coredns已经删除了

3. 重建coredns
kubectl apply -f coredns.yaml
[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME                                  READY   STATUS    RESTARTS   AGE
coredns-7ff77c879f-5mmjg              1/1     Running   0          13s
coredns-7ff77c879f-t74th              1/1     Running   0          13s
etcd-k8s-master1                      1/1     Running   4          4d
kube-apiserver-k8s-master1            1/1     Running   3          4d
kube-controller-manager-k8s-master1   1/1     Running   3          4d
kube-flannel-ds-amd64-2ktxw           1/1     Running   1          4d
kube-flannel-ds-amd64-fd2cb           1/1     Running   1          4d
kube-flannel-ds-amd64-hb2zr           1/1     Running   4          4d
kube-proxy-4vt8f                      1/1     Running   4          4d
kube-proxy-5nv5t                      1/1     Running   2          4d
kube-proxy-9fgzh                      1/1     Running   2          4d
kube-scheduler-k8s-master1            1/1     Running   4          4d
日志复查:
coredns-7ff77c879f-5mmjg:
[root@k8s-master1 ~]# kubectl logs coredns-7ff77c879f-5mmjg -n kube-system
.:53
[INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7
CoreDNS-1.6.7
linux/amd64, go1.13.6, da7f65b

coredns-7ff77c879f-t74th:
[root@k8s-master1 ~]# kubectl  logs coredns-7ff77c879f-t74th -n kube-system
.:53
[INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7
CoreDNS-1.6.7
linux/amd64, go1.13.6, da7f65b

#k8s创建一个容器验证dns
[root@k8s-master1 ~]# kubectl run -it --rm --image=busybox:1.28.4 sh
/ # nslookup kubernetes
Server:    10.1.0.10
Address 1: 10.1.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.1.0.1 kubernetes.default.svc.cluster.local
#通过 nslookup来解析 kubernetes 能够出现解析,说明dns正常工作

15. 集群证书问题处理 [kuberadm部署的解决方案]

1. 删除默认的secret,使用自签证书创建新的secret
kubectl delete secret kubernetes-dashboard-certs -n kubernetes-dashboard
kubectl create secret generic kubernetes-dashboard-certs \
--from-file=/etc/kubernetes/pki/apiserver.key --from-file=/etc/kubernetes/pki/apiserver.crt -n kubernetes-dashboard

使用二进制部署的这里的证书需要根据自己当时存储的路径进行修改即可.

2. 证书配置后需要修改dashboard.yaml文件,重新构建dashboard
wget https://www.chenleilei.net/soft/k8s/recommended.yaml
vim recommended.yaml
找到: kind: Deployment,找到这里之后再次查找 args 看到这两行:
- --auto-generate-certificates
- --namespace=kubernetes-dashboard

改为[中间插入两行证书地址]:
- --auto-generate-certificates
- --tls-key-file=apiserver.key
- --tls-cert-file=apiserver.crt
- --namespace=kubernetes-dashboard

[已修改的,可直接使用: wget https://www.chenleilei.net/soft/k8s/dashboard.yaml]

3. 修改完毕后重新应用 recommended.yaml
kubectl apply -f recommended.yaml

应用后,可以看到触发了一次滚动更新,然后重新打开浏览器发现证书已经正常显示,不会提示不安全了.
[root@k8s-master1 ~]# kubectl get pods -n kubernetes-dashboard
NAME                                         READY   STATUS    RESTARTS   AGE
dashboard-metrics-scraper-694557449d-r9h5r   1/1     Running   0          2d1h
kubernetes-dashboard-5d8766c7cc-trdsv        1/1     Running   0          93s   <---滚动更新.

报错处理:

问题1 k8s-node节点加入时报错::

k8s-node节点加入时报错:
W0315 22:16:20.123204    5795 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[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/
error execution phase preflight: [preflight] Some fatal errors occurred:
	[ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]: /proc/sys/net/bridge/bridge-nf-call-iptables contents are not set to 1
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher

处理办法:
echo "1" >/proc/sys/net/bridge/bridge-nf-call-iptables
增加后重新加入:
kubeadm join 10.0.0.63:6443 --token 0dr1pw.ejybkufnjpalb8k6     --discovery-token-ca-cert-hash sha256:ca1aa9cb753a26d0185e3df410cad09d8ec4af4d7432d127f503f41bc2b14f2a
这里的token由kubadm服务器生成.

问题2: web页面无法访问处理:

重建dashboard
删除:
kubectl delete -f dashboard.yaml

删除后创建:
kubectl create -f dashboard.yaml
创建账户:
kubectl create serviceaccount dashboard-admin -n kubernetes-dashboard
查看密码:
kubectl describe secrets -n kubernetes-dashboard $(kubectl -n kubernetes-dashboard get secret | awk '/dashboard-admin/{print $1}')

重新打开登录即可

问题3: 部署dashboard失败

有可能是网络问题,需要切换一个别的网络,比如vpn,然后重新部署.

16. 在k8s中部署一个nginx

[root@k8s-master1 ~]# kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort
service/nginx exposed
[root@k8s-master1 ~]# kubectl get pod,svc
NAME                        READY   STATUS             RESTARTS   AGE
pod/nginx-f89759699-dnfmg   0/1     ImagePullBackOff   0          3m41s

ImagePullBackOff报错:
检查k8s日志:  kubectl describe pod nginx-f89759699-dnfmg
结果:
  Normal   Pulling    3m27s (x4 over 7m45s)  kubelet, k8s-node2  Pulling image "nginx"
  Warning  Failed     2m55s (x2 over 6m6s)   kubelet, k8s-node2  Failed to pull image "nginx": rpc error: code = Unknown desc = Get https://registry-1.docker.io/v2/library/nginx/manifests/sha256:cccef6d6bdea671c394956e24b0d0c44cd82dbe83f543a47fdc790fadea48422: net/http: TLS handshake timeout

可以看到是因为docker下载镜像报错,需要更新别的docker源
[root@k8s-master1 ~]# cat /etc/docker/daemon.json
{
  "registry-mirrors": ["https://ajvcw8qn.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"]
}

使用其中一个node节点docker来pull nginx:
然后发现了错误:
[root@k8s-node1 ~]# docker pull nginx
Using default tag: latest
latest: Pulling from library/nginx
54fec2fa59d0: Pulling fs layer
4ede6f09aefe: Pulling fs layer
f9dc69acb465: Pulling fs layer
Get https://registry-1.docker.io/v2/: net/http: TLS handshake timeout  #源没有修改

重新修改源后:
[root@k8s-master1 ~]# docker pull nginx
Using default tag: latest
latest: Pulling from library/nginx
54fec2fa59d0: Pull complete
4ede6f09aefe: Pull complete
f9dc69acb465: Pull complete
Digest: sha256:86ae264c3f4acb99b2dee4d0098c40cb8c46dcf9e1148f05d3a51c4df6758c12
Status: Downloaded newer image for nginx:latest
docker.io/library/nginx:latest

再次运行:
kubectl delete pod,svc nginx
kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort

这是一个k8s拉取镜像失败的排查过程:
1. k8s部署nginx失败,检查节点 kubectl get pod,svc
2. 检查k8s日志:  Failed to pull image "nginx": rpc error: code = Unknown desc = Get https://registry-
...net/http: TLS handshake timeout [出现这个故障可以看到是源没有更换]
3. 修改docker源为阿里云的.然后重新启动docker
cat /etc/docker/daemon.json
{
  "registry-mirrors": ["https://ajvcw8qn.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"]
}
systemctl restart docker.service
4. 再次使用docker pull 来下载一个nginx镜像, 发现已经可以拉取成功
5. 删除docker下载好的nginx镜像 docker image rm -f [镜像名]
6. k8s中删除部署失败的nginx   kubectl delete deployment nginx
7. 重新创建镜像 kubectl create deployment nginx --image=nginx
8. k8s重新部署应用: kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort

17. 暴露应用

1.创建镜像
kubectl create deployment nginx --image=nginx

2.暴露应用
kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort

18. 优化: k8s自动补全工具

yum install -y bash-completion
source <(kubectl completion bash)
source /usr/share/bash-completion/bash_completion

19. 本节问题点:

一. token过期处理办法:
   每隔24小时,之前创建的token就会过期,这样会无法登录集群的dashboard页面,此时需要重新生成token
   生成命令:
   kubeadm token create
   kubeadm token list
   openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'

  查询token
   openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
3d847b858ed649244b4110d4d60ffd57f43856f42ca9c22e12ca33946673ccb4

  然后使用新的token让新服务器加入:
   kubeadm join 10.0.0.63:6443 --token 0dr1pw.ejybkufnjpalb8k6     --discovery-token-ca-cert-hash sha256:3d847b858ed649244b4110d4d60ffd57f43856f42ca9c22e12ca33946673ccb4

 二. dashboard登录密码获取
 kubectl describe secrets -n kubernetes-dashboard $(kubectl -n kubernetes-dashboard get secret | awk '/dashboard-admin/{print $1}')

 三. k8s拉取镜像失败的排查过程
 1. k8s部署nginx失败,检查节点 kubectl get pod,svc
 2. 检查k8s日志:  Failed to pull image "nginx": rpc error: code = Unknown desc = Get https://registry-
...net/http: TLS handshake timeout [出现这个故障可以看到是源没有更换]
 3. 修改docker源为阿里云的.然后重新启动docker
cat /etc/docker/daemon.json
{
  "registry-mirrors": ["https://ajvcw8qn.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"]
}
systemctl restart docker.service
 4. 再次使用docker pull 来下载一个nginx镜像, 发现已经可以拉取成功
 5. 删除docker下载好的nginx镜像 docker image rm -f [镜像名]
 6. k8s中删除部署失败的nginx   kubectl delete deployment nginx
 7. 重新创建镜像 kubectl create deployment nginx --image=nginx
 8. k8s重新部署应用: kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort

20. YAML附件[请保存为 .yaml 为后缀]

https://www.chenleilei.net/soft/kubeadm快速部署一个Kubernetes集群yaml.zip