【进阶】2、搭建K8s集群【v1.23】

[toc]

一、安装要求

在开始之前，部署Kubernetes集群机器需要满足以下几个条件：

一台或多台机器，操作系统 CentOS7.x-86_x64
硬件配置：2GB或更多RAM，2个CPU或更多CPU，硬盘30GB或更多
集群中所有机器之间网络互通
可以访问外网，需要拉取镜像
禁止swap分区

二、准备环境

kubernetesæž¶æž„å›¾

角色	IP
k8s-master	192.168.50.114
k8s-node1	192.168.50.115
k8s-node2	192.168.50.116
k8s-node3	192.168.50.120

#关闭防火墙：
systemctl stop firewalld
systemctl disable firewalld

#关闭selinux：
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 临时

#关闭swap：
# 临时关闭
swapoff -a  
# 永久
sed -ri 's/.*swap.*/#&/' /etc/fstab  

#设置主机名：
hostnamectl set-hostname <hostname>

#在master添加hosts：
cat >> /etc/hosts << EOF
192.168.50.114 k8s-master
192.168.50.115 k8s-node1
192.168.50.116 k8s-node2
192.168.50.120 k8s-node3
EOF

#将桥接的IPv4流量传递到iptables的链：
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
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
sysctl --system


#时间同步：
yum install ntpdate -y
ntpdate time.windows.com

#修改时区
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

#修改语言
sudo echo 'LANG="en_US.UTF-8"' >> /etc/profile;source /etc/profile

#升级内核
cp /etc/default/grub /etc/default/grub-bak
rpm -ivh kernel-lt-5.4.186-1.el7.elrepo.x86_64.rpm 
grub2-set-default 0
grub2-mkconfig -o /boot/grub2/grub.cfg
grub2-editenv list
yum makecache
awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg
reboot
uname -r

#安装ipvs模块
yum install ipset ipvsadm -y
modprobe br_netfilter
#### 内核3.10  ####
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
#### 内核5.4  ####
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack
EOF
################## 高版本的centos内核nf_conntrack_ipv4被nf_conntrack替换了
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack

三、安装Docker/kubeadm/kubelet【所有节点】

Kubernetes默认CRI（容器运行时）为Docker，因此先安装Docker。

3.1 安装Docker

#移除docker
sudo yum -y remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-selinux \
                  docker-engine-selinux \
                  docker-ce-cli \
                  docker-engine
#查看还有没有存在的docker组件
rpm -qa|grep docker
#有则通过命令 yum -y remove XXX 来删除,比如：
#yum remove docker-ce-cli

#安装最新版docker
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
#yum -y install docker-ce
yum  -y install docker-ce-20.10.10-3.el7  


systemctl daemon-reload
systemctl start docker
systemctl enable docker
docker ps 
#确认镜像目录是否改变
docker info |grep "Docker Root Dir"
docker --version

#配置harbor地址
#vim /lib/systemd/system/docker.service
#改为
ExecStart=/usr/bin/dockerd -H fd:// --insecure-registry https://docker.gayj.cn:444 --containerd=/run/containerd/containerd.sock

#配置镜像下载加速器和数据路径：
mkdir -p /data/docker
cat >/etc/docker/daemon.json <<EOF
{
"data-root": "/data/docker" ,
 "exec-opts": ["native.cgroupdriver=systemd"],
"registry-mirrors": ["https://almtd3fa.mirror.aliyuncs.com"]
}
EOF
#删除之前的数据目录
rm -rvf  /var/lib/docker
systemctl daemon-reload
systemctl restart docker
docker ps 
#确认镜像目录是否改变
docker info |grep "Docker Root Dir"
docker --version

3.2 添加阿里云YUM软件源

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
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

3.3 安装kubeadm，kubelet和kubectl

由于版本更新频繁，这里指定版本号部署：

yum install -y kubelet-1.23.0 kubeadm-1.23.0 kubectl-1.23.0
systemctl enable kubelet

【数据目录修改】

https://blog.csdn.net/qq_39826987/article/details/126473129?spm=1001.2014.3001.5502

四、部署Kubernetes Master

https://kubernetes.io/zh/docs/reference/setup-tools/kubeadm/kubeadm-init/#config-file

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#initializing-your-control-plane-node

在192.168.50.114（Master）执行。

kubeadm init \
  --apiserver-advertise-address=192.168.50.114 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.23.0 \
  --service-cidr=10.96.0.0/12 \
  --pod-network-cidr=10.244.0.0/16 
#  --ignore-preflight-errors=all  忽略报错注释掉。

–apiserver-advertise-address 集群通告地址
–image-repository 由于默认拉取镜像地址k8s.gcr.io国内无法访问，这里指定阿里云镜像仓库地址
–kubernetes-version K8s版本，与上面安装的一致
–service-cidr 集群内部虚拟网络，Pod统一访问入口
–pod-network-cidr Pod网络，，与下面部署的CNI网络组件yaml中保持一致

或者使用配置文件引导：

$ vi kubeadm.conf
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.23.0
imageRepository: registry.aliyuncs.com/google_containers 
networking:
  podSubnet: 10.244.0.0/16 
  serviceSubnet: 10.96.0.0/12 

$ kubeadm init --config kubeadm.conf --ignore-preflight-errors=all

拷贝kubectl使用的连接k8s认证文件到默认路径：

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

$ kubectl get nodes
NAME               STATUS     ROLES            AGE   VERSION
localhost.localdomain   NotReady   control-plane,master   20s   v1.20.0

五、加入Kubernetes Node

在192.168.4.114/115/118（Node）执行。

向集群添加新节点，执行在kubeadm init输出的kubeadm join命令：

kubeadm join 192.168.4.114:6443 --token 7gqt13.kncw9hg5085iwclx \
--discovery-token-ca-cert-hash sha256:66fbfcf18649a5841474c2dc4b9ff90c02fc05de0798ed690e1754437be35a01

默认token有效期为24小时，当过期之后，该token就不可用了。这时就需要重新创建token，可以直接使用命令快捷生成：

kubeadm token create --print-join-command

https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-join/

六、部署容器网络（CNI）

1）官网

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#pod-network

注意：只需要部署下面其中一个，推荐Calico。

Calico是一个纯三层的数据中心网络方案，Calico支持广泛的平台，包括Kubernetes、OpenStack等。

Calico 在每一个计算节点利用 Linux Kernel 实现了一个高效的虚拟路由器（ vRouter）来负责数据转发，而每个 vRouter 通过 BGP 协议负责把自己上运行的 workload 的路由信息向整个 Calico 网络内传播。

此外，Calico 项目还实现了 Kubernetes 网络策略，提供ACL功能。

【官方说明】

https://docs.projectcalico.org/getting-started/kubernetes/quickstart

【git地址】

https://github.com/projectcalico/calico/tree/v3.24.0

【部署地址】

https://docs.tigera.io/archive/v3.14/getting-started/kubernetes/quickstart

【说明】https://blog.csdn.net/ma_jiang/article/details/124962352

2）部署修改

# --no-check-certificate
wget -c https://docs.projectcalico.org/v3.20/manifests/calico.yaml --no-check-certificate

下载完后还需要修改里面定义Pod网络（CALICO_IPV4POOL_CIDR），与前面kubeadm init指定的一样

修改完后应用清单：

#修改为：
            - name: CALICO_IPV4POOL_CIDR
              value: "10.244.0.0/16"


                  key: calico_backend
            # Cluster type to identify the deployment type
            - name: CLUSTER_TYPE
              value: "k8s,bgp"
            # 下方新增
            - name: IP_AUTODETECTION_METHOD
              value: "interface=ens192"
    # ens192为本地网卡名字

3）更换模式为bgp

#修改CALICO_IPV4POOL_IPIP为Never，不过这种方式只适用于第一次部署，也就是如果已经部署了IPIP模式，这种方式就不奏效了，除非把calico删除，修改。
#更改IPIP模式为bgp模式，可以提高网速，但是节点之前相互不能通信。
            - name: CALICO_IPV4POOL_IPIP
              value: "Always"
#修改yaml
            - name: CALICO_IPV4POOL_IPIP
              value: "Never"

【报错】Warning: policy/v1beta1 PodDisruptionBudget is deprecated in v1.21+, unavailable in v1.25+; use policy/v1 PodDisruptionBudget

【原因】api版本已经过期，需要修改下。
将rbac.authorization.k8s.io/v1beta1 修改为rbac.authorization.k8s.io/v1

4）下载镜像

#quay.io是一个公共镜像仓库
docker pull quay.io/calico/cni:3.20.6
docker tag quay.io/calico/cni:v3.20.6 calico/cni:v3.20.6

docker pull quay.io/calico/kube-controllers:v3.20.6
docker tag quay.io/calico/kube-controllers:v3.20.6 calico/kube-controllers:v3.20.6

docker pull quay.io/calico/node:v3.20.6
docker tag quay.io/calico/node:v3.20.6 calico/node:v3.20.6

docker pull quay.io/calico/pod2daemon-flexvol:v3.20.6
docker tag quay.io/calico/pod2daemon-flexvol:v3.14.2 calico/pod2daemon-flexvol:v3.20.6

docker pull quay.io/calico/typha:v3.20.6
docker tag quay.io/calico/typha:v3.20.6 calico/typha:v3.20.6

#生效
kubectl apply -f calico.yaml
kubectl get pods -n kube-system

5）更改网络模式为ipvs

#修改网络模式为IPVS
[root@k8s-master ~]# kubectl edit -n kube-system cm kube-proxy
修改：将mode: " "
修改为mode: “ipvs”
:wq保存退出

#看kube-system命名空间下的kube-proxy并删除，删除后，k8s会自动再次生成，新生成的kube-proxy会采用刚刚配置的ipvs模式
kubectl get pod -n kube-system |grep kube-proxy |awk '{system("kubectl delete pod "$1" -n kube-system")}'

#清除防火墙规则
iptables -t filter -F; iptables -t filter -X; iptables -t nat -F; iptables -t nat -X

#查看日志，确认使用的是ipvs，下面的命令，将proxy的名字换成自己查询出来的名字即可
[root@k8s-master ~]# kubectl get pod -n kube-system | grep kube-proxy
kube-proxy-2bvgz                           1/1     Running   0              34s
kube-proxy-hkctn                           1/1     Running   0              35s
kube-proxy-pjf5j                           1/1     Running   0              38s
kube-proxy-t5qbc                           1/1     Running   0              36s
[root@k8s-master ~]# kubectl logs -n kube-system kube-proxy-pjf5j
I0303 04:32:34.613408       1 node.go:163] Successfully retrieved node IP: 192.168.50.116
I0303 04:32:34.613505       1 server_others.go:138] "Detected node IP" address="192.168.50.116"
I0303 04:32:34.656137       1 server_others.go:269] "Using ipvs Proxier"
I0303 04:32:34.656170       1 server_others.go:271] "Creating dualStackProxier for ipvs"

#通过ipvsadm命令查看是否正常，判断ipvs开启了
[root@k8s-master ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.17.0.1:32684 rr
  -> 10.244.36.65:80              Masq    1      0          0         
TCP  192.168.50.114:32684 rr
  -> 10.244.36.65:80              Masq    1      0          0         
TCP  10.96.0.1:443 rr
  -> 192.168.50.114:6443          Masq    1      0          0         
TCP  10.96.0.10:53 rr
  -> 10.244.36.64:53              Masq    1      0          0         
  -> 10.244.169.128:53            Masq    1      0          0         
TCP  10.96.0.10:9153 rr
  -> 10.244.36.64:9153            Masq    1      0          0         
  -> 10.244.169.128:9153          Masq    1      0          0         
TCP  10.105.5.170:80 rr
  -> 10.244.36.65:80              Masq    1      0          0         
UDP  10.96.0.10:53 rr
  -> 10.244.36.64:53              Masq    1      0          0         
  -> 10.244.169.128:53            Masq    1      0          0

七、测试kubernetes集群

验证Pod工作
验证Pod网络通信
验证DNS解析

在Kubernetes集群中创建一个pod，验证是否正常运行：

kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort
kubectl get pod,svc

访问地址：http://NodeIP:Port

八、部署 Dashboard

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.3/aio/deploy/recommended.yaml

默认Dashboard只能集群内部访问，修改Service为NodePort类型，暴露到外部：

$ vi recommended.yaml
...
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30000
  selector:
    k8s-app: kubernetes-dashboard
  type: NodePort
...

$ kubectl apply -f recommended.yaml
$ kubectl get pods -n kubernetes-dashboard
NAME                                         READY   STATUS    RESTARTS   AGE
dashboard-metrics-scraper-6b4884c9d5-gl8nr   1/1     Running   0          13m
kubernetes-dashboard-7f99b75bf4-89cds        1/1     Running   0          13m

访问地址：https://NodeIP:30000

创建service account并绑定默认cluster-admin管理员集群角色：

# 创建用户
kubectl create serviceaccount dashboard-admin -n kube-system
# 用户授权
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
#解决WEB页面报错
kubectl create clusterrolebinding system:anonymous   --clusterrole=cluster-admin  --user=system:anonymous

#访问：https://node节点:30000/

https://192.168.4.115:30000/

# 获取用户Token
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

使用输出的token登录Dashboard。

九、解决谷歌不能登录dashboard

#查看
kubectl get secrets  -n  kubernetes-dashboard

#删除默认的secret，用自签证书创建新的secret
kubectl delete secret kubernetes-dashboard-certs -n kubernetes-dashboard

#创建ca
openssl genrsa -out ca.key 2048
openssl req -new -x509 -key ca.key -out ca.crt -days 3650 -subj "/C=CN/ST=HB/L=WH/O=DM/OU=YPT/CN=CA"
openssl x509 -in ca.crt -noout -text

#签发Dashboard证书
openssl genrsa -out dashboard.key 2048
openssl req -new -key dashboard.key -out dashboard.csr -subj "/O=white/CN=dasnboard"
openssl x509 -req -in dashboard.csr  -CA ca.crt -CAkey ca.key -CAcreateserial -out dashboard.crt -days 3650


#生成新的secret
kubectl create secret generic kubernetes-dashboard-certs  --from-file=dashboard.crt=/opt/dashboard/dashboard.crt --from-file=dashboard.key=/opt/dashboard/dashboard.key -n kubernetes-dashboard

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

# vim recommended.yaml 加入证书路径
          args:
            - --auto-generate-certificates
            - --tls-key-file=dashboard.key
            - --tls-cert-file=dashboard.crt
#           - --tls-key-file=apiserver.key
#           - --tls-cert-file=apiserver.crt

#重新生效
kubectl apply  -f recommended.yaml 

#删除pods重新生效
kubectl get pod -n kubernetes-dashboard | grep -v NAME | awk '{print "kubectl delete po " $1 " -n kubernetes-dashboard"}' | sh

访问：https://192.168.4.116:30000/#/login

# 获取用户Token
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

十、安装metrics

#下载
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/metrics-server:v0.5.0
#改名
docker tag   registry.cn-hangzhou.aliyuncs.com/google_containers/metrics-server:v0.5.0 k8s.gcr.io/metrics-server/metrics-server:v0.5.0
#删除已经改名镜像
docker rmi -f registry.cn-hangzhou.aliyuncs.com/google_containers/metrics-server:v0.5.0
#创建目录
mkdir -p /opt/k8s/metrics-server
cd /opt/k8s/metrics-server

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
    rbac.authorization.k8s.io/aggregate-to-admin: "true"
    rbac.authorization.k8s.io/aggregate-to-edit: "true"
    rbac.authorization.k8s.io/aggregate-to-view: "true"
  name: system:aggregated-metrics-reader
rules:
- apiGroups:
  - metrics.k8s.io
  resources:
  - pods
  - nodes
  verbs:
  - get
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
rules:
- apiGroups:
  - ""
  resources:
  - pods
  - nodes
  - nodes/stats
  - namespaces
  - configmaps
  verbs:
  - get
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server-auth-reader
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: extension-apiserver-authentication-reader
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server:system:auth-delegator
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:auth-delegator
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:metrics-server
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  ports:
  - name: https
    port: 443
    protocol: TCP
    targetPort: https
  selector:
    k8s-app: metrics-server
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  strategy:
    rollingUpdate:
      maxUnavailable: 0
  template:
    metadata:
      labels:
        k8s-app: metrics-server
    spec:
      containers:
      - args:
        - --cert-dir=/tmp
        - --secure-port=443
        - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
        - --kubelet-use-node-status-port
        - --metric-resolution=15s
        - --kubelet-insecure-tls
        image: k8s.gcr.io/metrics-server/metrics-server:v0.5.0
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /livez
            port: https
            scheme: HTTPS
          periodSeconds: 10
        name: metrics-server
        ports:
        - containerPort: 443
          name: https
          protocol: TCP
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /readyz
            port: https
            scheme: HTTPS
          initialDelaySeconds: 20
          periodSeconds: 10
        resources:
          requests:
            cpu: 100m
            memory: 200Mi
        securityContext:
          readOnlyRootFilesystem: true
          runAsNonRoot: true
          runAsUser: 1000
        volumeMounts:
        - mountPath: /tmp
          name: tmp-dir
      nodeSelector:
        kubernetes.io/os: linux
      priorityClassName: system-cluster-critical
      serviceAccountName: metrics-server
      volumes:
      - emptyDir: {}
        name: tmp-dir
---
apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:
  labels:
    k8s-app: metrics-server
  name: v1beta1.metrics.k8s.io
spec:
  group: metrics.k8s.io
  groupPriorityMinimum: 100
  insecureSkipTLSVerify: true
  service:
    name: metrics-server
    namespace: kube-system
  version: v1beta1
  versionPriority: 100

十一、切换容器引擎为Containerd

https://kubernetes.io/zh/docs/setup/production-environment/container-runtimes/#containerd

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1、配置先决条件

cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter
#查看模块
lsmod  |grep overlay
lsmod  |grep br_netfilter


# 设置必需的 sysctl 参数，这些参数在重新启动后仍然存在。
cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf
net.bridge.bridge-nf-call-iptables  = 1
net.ipv4.ip_forward                 = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF

# 生效
sudo sysctl --system

2、安装containerd

yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo
yum update -y && sudo yum install -y containerd.io
mkdir -p /etc/containerd
containerd config default | sudo tee /etc/containerd/config.toml
systemctl restart containerd

3、修改配置文件

$ vi /etc/containerd/config.toml
   [plugins."io.containerd.grpc.v1.cri"]
      sandbox_image = "registry.aliyuncs.com/google_containers/pause:3.2"  
         ...
         [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
             SystemdCgroup = true
             ...
        [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]
          endpoint = ["https://b9pmyelo.mirror.aliyuncs.com"]
          
systemctl restart containerd
systemctl enable  containerd
systemctl stop docker

4、配置kubelet使用containerd

vi /etc/sysconfig/kubelet 
KUBELET_EXTRA_ARGS=--container-runtime=remote --container-runtime-endpoint=unix:///run/containerd/containerd.sock --cgroup-driver=systemd

systemctl restart kubelet

5、验证

[root@k8s-master ~]# kubectl get node -o wide
NAME         STATUS   ROLES                  AGE   VERSION   INTERNAL-IP     EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION                CONTAINER-RUNTIME
k8s-master   Ready    control-plane,master   24h   v1.20.0   192.168.4.114   <none>        CentOS Linux 7 (Core)   3.10.0-1127.19.1.el7.x86_64   docker://20.10.8
k8s-node1    Ready    <none>                 24h   v1.20.0   192.168.4.115   <none>        CentOS Linux 7 (Core)   3.10.0-1127.19.1.el7.x86_64   docker://20.10.8
k8s-node2    Ready    <none>                 24h   v1.20.0   192.168.4.116   <none>        CentOS Linux 7 (Core)   3.10.0-1127.19.1.el7.x86_64   docker://20.10.8
k8s-node3    Ready    <none>                 24h   v1.22.1   192.168.4.118   <none>        CentOS Linux 7 (Core)   3.10.0-1127.19.1.el7.x86_64   containerd://1.4.9

十一、crictl管理容器

crictl 是 CRI 兼容的容器运行时命令行接口。你可以使用它来检查和调试 Kubernetes 节点上的容器运行时和应用程序。 crictl 和它的源代码在 cri-tools 代码库。

【视频】https://asciinema.org/a/179047

【使用网址】https://kubernetes.io/zh/docs/tasks/debug-application-cluster/crictl/

十二、常用命令

1、常用命令

#查看master组件状态：
kubectl get cs

#查看node状态：
kubectl get node

#查看Apiserver代理的URL：
kubectl cluster-info

#查看集群详细信息：
kubectl cluster-info dump

#查看资源信息：
kubectl describe <资源> <名称>

#查看K8S信息
kubectl api-resources

2、命令操作+


[root@k8s-master ~]# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                                                       ERROR
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused
etcd-0               Healthy     {"health":"true"}

#修改yaml，注释掉port
$ vim /etc/kubernetes/manifests/kube-scheduler.yaml
$ vim /etc/kubernetes/manifests/kube-controller-manager.yaml
#    - --port=0

#重启
systemctl restart kubelet

#查看master组件
[root@k8s-master ~]# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok
scheduler            Healthy   ok
etcd-0               Healthy   {"health":"true"}