k8s安装与踩坑

k8s安装与踩坑K8S安装部署（一）准备工作1.安装CentOS虚拟机、关闭防火墙、SELinux、禁用Swap2.禁用Swap3.配置主机名和IP的host信息4.所有节点安装Docker5.配置Docker的镜像加速器（二）使用kubeadmin部署K8s集群1.安装kubelet kubeadm kubectl（master /node)2.关闭交换区 (master/node)3.网桥配置

BorisCao

742人浏览 · 2020-12-31 17:03:07

BorisCao · 2020-12-31 17:03:07 发布

k8s安装与踩坑

K8S安装部署
问题分析
- kubelet启动失败
常用命令
- - 获取所有节点信息
  - 查看存在问题的的pod
参考资料

K8S安装部署

（一）准备工作

1.安装CentOS虚拟机、关闭防火墙、SELinux、禁用Swap

systemctl stop firewalld.service
systemctl disable firewalld.service
sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0

2.禁用Swap

默认情况下，Kubelet不允许所在的主机存在交换分区，后期规划的时候，可以考虑在系统安装的时候不创建交换分区，针对已经存在交换分区的可以设置忽略禁止使用Swap的限制，不然无法启动Kubelet

swapoff -a
vi /etc/fstab 
#swap一行注释

3.配置主机名和IP的host信息

编辑每个节点的/etc/hosts文件，如下：

192.168.6.231 k8s-master
192.168.6.232 k8s-node1
192.168.6.233 k8s-node2

4.所有节点安装Docker

yum -y install wget
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-18.06.1.ce-3.el7
systemctl enable docker && systemctl start docker
docker --version

5.配置Docker的镜像加速器

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://fy707np5.mirror.aliyuncs.com/"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

（二）使用kubeadmin部署K8s集群

1.安装kubelet kubeadm kubectl（master /node)

Kubernetes v1.20.1

如果安装过，可以先删除

yum remove -y  kubelet kubeadm kubectl

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

# Set SELinux in permissive mode (effectively disabling it)
sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

sudo yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes

sudo systemctl enable --now kubelet

2.关闭交换区 (master/node)

swapoff -a
vi /etc/fstab
#swap一行注释

3.网桥配置(master/node)

# echo "1" >/proc/sys/net/bridge/bridge-nf-call-iptables

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sudo sysctl --system

4.docker daemon 修改(master/node)

cat <<EOF | sudo tee /etc/docker/daemon.json
{
        "registry-mirrors": ["https://fy707np5.mirror.aliyuncs.com/"]
       ,"exec-opts":["native.cgroupdriver=systemd"]
      }
EOF

systemctl restart docker

systemctl status docker

4.kubeadm init(master)

kubeadm init \
--apiserver-advertise-address=192.168.6.232 \
--image-repository registry.aliyuncs.com/google_containers \
--kubernetes-version v1.20.1 \
--service-cidr=10.1.0.0/16 \
--pod-network-cidr=10.244.0.0/16

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

记录节点加入语句,例如

kubeadm join 192.168.6.231:6443 --token zdb9vu.g1gximj8n22sfg3u \
    --discovery-token-ca-cert-hash sha256:b7b014d0d297cb40b79b9b27d97a3e206c40a5ad159ea41ccdc5d50e16b03ce4

5.查看节点信息(master)

kubectl get nodes
kubectl  get pod --all-namespaces

查看pod节点后，发现coredns这些服务还是Pending状态，表明缺少网络组件(flannel)

6.安装flannel网络组件(master)

kubectl apply -f kube-flannel.yml

https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml

保证coredns变成running

kube-flannel.yml

---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: psp.flannel.unprivileged
  annotations:
    seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
    seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
    apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
    apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
  privileged: false
  volumes:
  - configMap
  - secret
  - emptyDir
  - hostPath
  allowedHostPaths:
  - pathPrefix: "/etc/cni/net.d"
  - pathPrefix: "/etc/kube-flannel"
  - pathPrefix: "/run/flannel"
  readOnlyRootFilesystem: false
  # Users and groups
  runAsUser:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny
  # Privilege Escalation
  allowPrivilegeEscalation: false
  defaultAllowPrivilegeEscalation: false
  # Capabilities
  allowedCapabilities: ['NET_ADMIN', 'NET_RAW']
  defaultAddCapabilities: []
  requiredDropCapabilities: []
  # Host namespaces
  hostPID: false
  hostIPC: false
  hostNetwork: true
  hostPorts:
  - min: 0
    max: 65535
  # SELinux
  seLinux:
    # SELinux is unused in CaaSP
    rule: 'RunAsAny'
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
rules:
- apiGroups: ['extensions']
  resources: ['podsecuritypolicies']
  verbs: ['use']
  resourceNames: ['psp.flannel.unprivileged']
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - nodes
  verbs:
  - list
  - watch
- apiGroups:
  - ""
  resources:
  - nodes/status
  verbs:
  - patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flannel
  namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  cni-conf.json: |
    {
      "name": "cbr0",
      "cniVersion": "0.3.1",
      "plugins": [
        {
          "type": "flannel",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.13.1-rc1
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.13.1-rc1
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
            add: ["NET_ADMIN", "NET_RAW"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
      - name: run
        hostPath:
          path: /run/flannel
      - name: cni
        hostPath:
          path: /etc/cni/net.d
      - name: flannel-cfg
        configMap:
          name: kube-flannel-cfg

7.配置join node节点(node)

这个命令来源于kubeadm init时产生的

kubeadm join 192.168.6.231:6443 --token zdb9vu.g1gximj8n22sfg3u \
    --discovery-token-ca-cert-hash sha256:b7b014d0d297cb40b79b9b27d97a3e206c40a5ad159ea41ccdc5d50e16b03ce4

在master上查看节点是否添加成功

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如果没有记录join命令，可以咨询查看

（1）查看token

kubectl token list

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(2)创建token (24小时过期)

kubeadm token create

(3)加密值

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

（三）启动节点

systemctl start kubelet
systemctl enable kubelet #开机启动

（四）部署服务

1.编写deploy文档

deploy nginx

https://kubernetes.io/docs/tasks/run-application/run-stateless-application-deployment/

master服务上

mkdir -p /opt/k8s/delopy

cd /opt/k8s/deploy/

vi tomcat-deploy.yml

apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 2 # tells deployment to run 2 pods matching the template
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80

deplopy mysql

https://kubernetes.io/docs/tasks/run-application/run-single-instance-stateful-application/

2.操作命令

kubectl create -f tomcat-deploy.yml #创建部署

kubectl apply -f tomcat-deploy.yml #更新部署配置

kubectl get pod [-o wide] #查看已部署pod

kubectl describe pod pod名称 #查看Pod详细信息

kubectl logs [-f] pod名称 #查看pod输出日志

3.测试

单独部署deploy，只能在内网访问

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curl 10.244.2.2 #在内网上可以访问
curl 10.244.1.2 #在内网上可以访问

（五）部署service

1.编写service文档

https://kubernetes.io/docs/tasks/run-application/run-replicated-stateful-application/

https://kubernetes.io/docs/concepts/services-networking/service/

方式一：编写yaml

mkdir -p /opt/k8s/service

vi nginx-services.yaml

apiVersion: v1
kind: Service 
metadata:
  name: nginx-service
  labels: 
    app: nginx-service
spec:
  type: NodePort
  selector:
    app: nginx
  ports:  
  - port: 80
    targetPort: 80
    nodePort: 30001

方式二：

kubectl expose deployment nginx-deployment --type=NodePort --name=example-service

2.操作命令

kubectl apply -f nginx-services.yaml  #启动service
kubectl delete service 服务名  #删除service

kubectl get service -o wide  #查看service

3.测试

部署service后，通过master和node都可以访问了

curl 192.168.132.31:30001   #master
curl 192.168.132.32:30001   #node1
curl 192.168.132.33:30001   #node2

4.deployment 和service 写入同一个配置文件

vi /opt/k8s/deploy/nginx-deploy-all.yaml

apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 2 # tells deployment to run 2 pods matching the template
  template:
    metadata:
      labels: 
        app: nginx
    spec:   
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:  
        - containerPort: 80

---
apiVersion: v1
kind: Service 
metadata:
  name: nginx-service
  labels: 
    app: nginx-service
spec:
  type: NodePort
  selector:
    app: nginx
  ports:  
  - port: 80
    targetPort: 80
    nodePort: 30001

kubectl apply -y nginx-deploy-all.yaml #启动

5.一个pod文件部署多个服务

apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: nginx-tomcat-deployment
spec:
  selector:
    matchLabels:
      app: nginx-tocat
  replicas: 2 # tells deployment to run 2 pods matching the template
  template:
    metadata:
      labels: 
        app: nginx-tocat
    spec:   
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:  
        - containerPort: 80
      - name: tomcat
        image: tomcat:9.0
        ports:  
        - containerPort: 8080
        volumeMounts:
        - name: web-app 
          mountPath: /usr/local/tomcat/webapps
      volumes:
      - name: web-app 
        hostPath:
         path: /web-path
---
apiVersion: v1
kind: Service 
metadata:
  name: nginx-tomcat-service
  labels: 
    app: nginx-tomcat-service
spec:
  type: NodePort
  selector:
    app: nginx-tocat
  ports:
  - port: 80
    name: nginx
    targetPort: 80
    nodePort: 30001
  - port: 8080
    name: tomcat
    targetPort: 8080
    nodePort: 30002

kubectl apply -f nginx-tomcat-all.yaml

问题分析

kubelet启动失败

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查看日志

journalctl _PID=7293 | vim -

systemctl restart kubelet && journalctl -xefu kubelet

journalctl -u kubelet

kubelete删除

yum remove -y  kubelet kubeadm kubectl

kubeadm token list

Warning：detected “cgroupfs” as the Docker cgroup driver. The recommended driver is “systemd”.

vi /etc/docker/daemon.json

{
        "registry-mirrors": ["https://fy707np5.mirror.aliyuncs.com/"]
       ,"exec-opts":["native.cgroupdriver=systemd"]
      }

systemctl restart docker

systemctl status docker

常用命令

获取所有节点信息

kubectl get nodes

查看存在问题的的pod

kubectl get pod --all-namespaces

kubectl get pod -o wide   #获取pod list
kubectl get service -o wide #获取service list
kubectl delete service 服务名 #删除service
kubectl get node -o wide  #获取node list

kubectl apply -y xx.yaml #部署服务、部署service
kubectl describe node loadtest-worker1 #获取node详细信息
kubectl logs -f tomcat-deployment-84ff9bf6b4-54bdp #查看日志

kubectl exec -it pod /bin/bash #进入容器