部署Kubernetes（k8s）集群，可视化部署kuboard

所需机器

主机名	地址	角色	配置
k8s-master	192.168.231.134	主节点	2核4G,centos7
k8s-node1	192.168.231.135	工作节点	2核4G,centos7
k8s-node2	192.168.231.136	工作节点	2核4G,centos7

主节点CPU核数必须是 ≥2核且内存要求必须≥2G，否则k8s无法启动

1. 集群环境部署【三台机器都需要做的操作】

1.关闭防火墙与selinux
2.时间同步
yum -y install ntpdate
ntpdate ntp.aliyun.com
3.配置静态ip
4.本地域名解析
cat>>/etc/hosts<EOF
192.168.231.134  k8s-master
192.168.231.135  k8s-node1
192.168.231.136  k8s-node2
EOF
5.关闭swap分区，Kubernetes 1.8开始要求关闭系统的Swap，如果不关闭，默认配置下kubelet将无法启动。
# swapoff -a
修改/etc/fstab文件，注释掉SWAP的自动挂载，使用free -m确认swap已经关闭。
2.注释掉swap分区：
# sed -i 's/.*swap.*/#&/' /etc/fstab
# free -m
             total        used        free      shared  buff/cache   available
Mem:           3935         144        3415           8         375        3518
Swap:             0           0           0

2. 集群下载docker

配置阿里云Docker Yum源
  # yum install -y yum-utils device-mapper-persistent-data lvm2 git
   
 # yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

安装docker最新版本
 # yum install docker-ce -y

启动Docker服务，并设置开机自启：
    #systemctl enable docker
    #systemctl start docker

3. 向docker导入镜像【集群】

这里我们是已经有所需要的镜像包，因此直接导入

解压俩个包
# tar xf application.tar.xz
# tar xf kube-1.22.0.tar.xz

[root@k8s-master ~]# ls
anaconda-ks.cfg  application  application.tar.xz  calico.yaml  kube-1.22.0  kube-1.22.0.tar.xz  
[root@k8s-master ~]# cd application/ 
[root@k8s-master application]# ls
images  image.sh
###执行导入镜像脚本
[root@k8s-master application]# sh image.sh load

[root@k8s-master ~]# cd kube-1.22.0/
[root@k8s-master kube-1.22.0]# ls
get-docker-image.sh  images
###执行导入镜像脚本
[root@k8s-master kube-1.22.0]# sh get-docker-image.sh load

特别注意

所有机器都必须有镜像
每次部署都会有版本更新，具体版本要求，运行初始化过程失败会有版本提示
kubeadm的版本和镜像的版本必须是对应的

4. 安装Kubeadm包[集群]

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

所有节点：

1.安装依赖包及常用软件包
# yum install -y conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp wget vim net-tools git iproute lrzsz bash-completion tree bridge-utils unzip bind-utils gcc


2.安装对应版本
# yum install -y kubelet-1.22.0-0.x86_64 kubeadm-1.22.0-0.x86_64 kubectl-1.22.0-0.x86_64

3.加载ipvs相关内核模块
# cat <<EOF > /etc/modules-load.d/ipvs.conf 
ip_vs
ip_vs_lc
ip_vs_wlc
ip_vs_rr
ip_vs_wrr
ip_vs_lblc
ip_vs_lblcr
ip_vs_dh
ip_vs_sh
ip_vs_nq
ip_vs_sed
ip_vs_ftp
ip_vs_sh
nf_conntrack_ipv4
ip_tables
ip_set
xt_set
ipt_set
ipt_rpfilter
ipt_REJECT
ipip
EOF

4.配置：
配置转发相关参数，否则可能会出错
# cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
net.ipv4.tcp_tw_recycle=0
vm.swappiness=0
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_instances=8192
fs.inotify.max_user_watches=1048576
fs.file-max=52706963
fs.nr_open=52706963
net.ipv6.conf.all.disable_ipv6=1
net.netfilter.nf_conntrack_max=2310720
EOF

此时执行是否加载成功命令是没有显示的
# lsmod | grep ip_vs

5.配置启动集群

再次之前重启三台服务器

# reboot

配置变量：
[root@k8s-master ~]# DOCKER_CGROUPS=`docker info |grep 'Cgroup' | awk ' NR==1 {print $3}'`
[root@k8s-master ~]# echo $DOCKER_CGROUPS
systemd

配置kubelet的cgroups
# cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=$DOCKER_CGROUPS --pod-infra-container-image=k8s.gcr.io/pause:3.5"
EOF

启动
# systemctl daemon-reload
# systemctl enable kubelet && systemctl restart kubelet

注意：

在这里使用 # systemctl status kubelet，你会发现报错误信息；

10月 11 00:26:43 node1 systemd[1]: kubelet.service: main process exited, code=exited, status=255/n/a
10月 11 00:26:43 node1 systemd[1]: Unit kubelet.service entered failed state.
10月 11 00:26:43 node1 systemd[1]: kubelet.service failed.

运行 # journalctl -xefu kubelet 命令查看systemd日志才发现，真正的错误是：
    unable to load client CA file /etc/kubernetes/pki/ca.crt: open /etc/kubernetes/pki/ca.crt: no such file or directory
#这个错误在运行kubeadm init 生成CA证书后会被自动解决，此处可先忽略。
#简单地说就是在kubeadm init 之前kubelet会不断重启。

6. 配置master节点【master做】

运行初始化过程如下：
[root@kub-k8s-master]# kubeadm init --kubernetes-version=v1.22.0 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.231.134
注：
apiserver-advertise-address=192.168.231.134    ---master的ip地址。
--kubernetes-version=v1.22.0   --更具具体版本进行修改

执行完会输出一大堆信息，注意最后的一段

....
[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         ######这三条命令需要执行

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 192.168.231.134:6443 --token 93erio.hbn2ti6z50he0lqs \
    --discovery-token-ca-cert-hash sha256:3bc60f06a19bd09f38f3e05e5cff4299011b7110ca3281796668f4edb29a56d9  #需要记住

上面记录了完成的初始化输出的内容，根据输出的内容基本上可以看出手动初始化安装一个Kubernetes集群所需要的关键步骤。
其中有以下关键内容：
? ? [kubelet] 生成kubelet的配置文件”/var/lib/kubelet/config.yaml”
? ? [certificates]生成相关的各种证书
? ? [kubeconfig]生成相关的kubeconfig文件
? ? [bootstraptoken]生成token记录下来，后边使用kubeadm join往集群中添加节点时会用到

配置节点1

如下操作在master节点操作
[root@kub-k8s-master ~]# rm -rf $HOME/.kube
[root@kub-k8s-master ~]# mkdir -p $HOME/.kube
[root@kub-k8s-master ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

查看node节点

[root@k8s-master ~]# kubectl get nodes
NAME         STATUS   ROLES                  AGE    VERSION
k8s-master   Ready    control-plane,master   5h5m   v1.22.0

7.配置使用网络插件【master做】

执行
# curl -L https://docs.projectcalico.org/v3.22/manifests/calico.yaml -O
# kubectl apply -f  calico.yaml

# kubectl get pod -A
NAMESPACE     NAME                                       READY   STATUS    RESTARTS   AGE
kube-system   calico-kube-controllers-6d9cdcd744-8jt5g   1/1     Running   0          6m50s
kube-system   calico-node-rkz4s                          1/1     Running   0          6m50s
kube-system   coredns-74ff55c5b-bcfzg                    1/1     Running   0          52m
kube-system   coredns-74ff55c5b-qxl6z                    1/1     Running   0          52m
kube-system   etcd-kub-k8s-master                        1/1     Running   0          53m
kube-system   kube-apiserver-kub-k8s-master              1/1     Running   0          53m
kube-system   kube-controller-manager-kub-k8s-master     1/1     Running   0          53m
kube-system   kube-proxy-gfhkf                           1/1     Running   0          52m
kube-system   kube-scheduler-kub-k8s-master              1/1     Running   0          53m

8.node节点加入集群【node做】

在所有node节点操作，此命令为初始化master成功后返回的结果

# kubeadm join 192.168.231.134:6443 --token 93erio.hbn2ti6z50he0lqs \
    --discovery-token-ca-cert-hash sha256:3bc60f06a19bd09f38f3e05e5cff4299011b7110ca3281796668f4edb29a56d9

9.后续检查【master做】

查看pods：
[root@k8s-master ~]# kubectl get pods -n kube-system
NAME                                       READY   STATUS    RESTARTS      AGE
calico-kube-controllers-7c87c5f9b8-cbh9g   1/1     Running   2 (31m ago)   5h5m
calico-node-7m5tq                          1/1     Running   1 (31m ago)   5h5m
calico-node-bth4k                          1/1     Running   1 (31m ago)   5h5m
calico-node-zp4tx                          1/1     Running   1 (31m ago)   5h5m
coredns-78fcd69978-ff6bj                   1/1     Running   1 (31m ago)   5h9m
coredns-78fcd69978-n4x55                   1/1     Running   1 (31m ago)   5h9m
etcd-k8s-master                            1/1     Running   1 (31m ago)   5h9m
kube-apiserver-k8s-master                  1/1     Running   1 (31m ago)   5h9m
kube-controller-manager-k8s-master         1/1     Running   1 (31m ago)   5h9m
kube-proxy-bmv9m                           1/1     Running   1 (31m ago)   5h9m
kube-proxy-k7zrz                           1/1     Running   1 (31m ago)   5h6m
kube-proxy-vcg62                           1/1     Running   1 (31m ago)   5h6m
kube-scheduler-k8s-master                  1/1     Running   1 (31m ago)   5h9m

查看节点
[root@k8s-master ~]# kubectl get nodes
NAME         STATUS   ROLES                  AGE     VERSION
k8s-master   Ready    control-plane,master   5h10m   v1.22.0
k8s-node1    Ready    <none>                 5h6m    v1.22.0
k8s-node2    Ready    <none>                 5h6m    v1.22.0

到此集群配置完成

错误改正

#> 如果集群初始化失败：(每个节点都要执行)
$ kubeadm reset -f; ipvsadm --clear; rm -rf ~/.kube
$ systemctl restart kubelet

#> 如果忘记token值
$ kubeadm token create --print-join-command
$ kubeadm init phase upload-certs --upload-certs

可视化部署---kuboard

[root@kube-master ~]# kubectl apply -f https://addons.kuboard.cn/kuboard/kuboard-v3.yaml
输出这些信息
namespace/kuboard created
configmap/kuboard-v3-config created
serviceaccount/kuboard-boostrap created
clusterrolebinding.rbac.authorization.k8s.io/kuboard-boostrap-crb created
daemonset.apps/kuboard-etcd created
deployment.apps/kuboard-v3 created
service/kuboard-v3 created

查看kuboard的pod是否启动

[root@kube-master ~]# kubectl get pod -n kuboard
NAME                               READY   STATUS    RESTARTS         AGE
kuboard-agent-2-5c54dcb98f-4vqvc   1/1     Running   24 (7m50s ago)   16d
kuboard-agent-747b97fdb7-j42wr     1/1     Running   24 (7m34s ago)   16d
kuboard-etcd-ccdxk                 1/1     Running   16 (8m58s ago)   16d
kuboard-etcd-k586q                 1/1     Running   16 (8m53s ago)   16d
kuboard-questdb-bd65d6b96-rgx4x    1/1     Running   10 (8m53s ago)   16d
kuboard-v3-5fc46b5557-zwnsf        1/1     Running   12 (8m53s ago)   16d

该过程可能需要一些时间，需耐心等待

查看service对象，30080端口

[root@k8s-master ~]# kubectl get svc -n kuboard
NAME         TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)                                        AGE
kuboard-v3   NodePort   10.101.117.230   <none>        80:30080/TCP,10081:30081/TCP,10081:30081/UDP   134m

web端访问 master端的IP

http://192.168.231.134:30080

用户：admin

密码：Kuboard123