基于Centos7.9搭建K8S集群（网络插件：flannel）

parameter_wzj

已于 2024-11-07 18:48:04 修改

阅读量1k

点赞数 10

文章标签： kubernetes 网络容器

于 2024-11-07 18:45:46 首次发布

本文链接：https://blog.youkuaiyun.com/parameter_wzj/article/details/143603122

版权

一、Centost7.9安装K8s集群（v1.28.0）

角色	IP地址
k8s-master	192.168.88.10
k8s-node1	192.168.88.11
k8s-node2	192.168.88.12

虚拟机配置建议：4核CPU、4G内存、20G硬盘
服务器可以访问互联网，会联网下载镜像

二、基础配置（三台都需要配置）

软件	版本
操作系统	CentOS-7-x86_64-DVD-2009.iso
Docker	Docker version 26.1.4
kubernetes	v1.28.0

关闭Selinux
~]# sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
~]# setenforce 0  # 临时
# 关闭Swap
~]# swapoff -a  # 临时
~]# sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

根据规划设置主机名

~]# hostnamectl set-hostname <hostname>

标题安装阿里云的yum源

curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo

确保网络桥接的数据包经过Iptables处理，启用相关的内核参数

~]# cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
~]# sysctl --system  # 生效

三、安装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
~]# systemctl enable docker && systemctl start docker

配置镜像下载加速器和设置Cgroup驱动

~]# cat > /etc/docker/daemon.json << EOF
  {
    "registry-mirrors": ["https:自己的阿里云镜像加速地址.aliyuncs.com"],
    "exec-opts": ["native.cgroupdriver=systemd"]
  }
EOF
~]# systemctl restart docker

标题安装cri-dockerd（Docker与Kubernetes通信的中间程序），有时候会出现安装包无法下载的问题

 wget https://github.com/Mirantis/cri-dockerd/releases/download/v0.3.2/cri-dockerd-0.3.2-3.el7.x86_64.rpm
 rpm -ivh cri-dockerd-0.3.2-3.el7.x86_64.rpm

指定依赖镜像地址为国内镜像地址：
~]# vi /usr/lib/systemd/system/cri-docker.service
ExecStart=/usr/bin/cri-dockerd --container-runtime-endpoint fd:// --pod-infra-container-image=registry.aliyuncs.com/google_containers/pause:3.9

~]# systemctl daemon-reload 
~]# systemctl enable cri-docker && systemctl start cri-docker

部署集群

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

安装kubeadm，kubelet和kubectl

~]# yum install -y kubelet-1.28.0 kubeadm-1.28.0 kubectl-1.28.0
~]# systemctl enable kubelet

初始化主节点

~]# kubeadm init   --apiserver-advertise-address=192.168.88.10   --image-repository registry.aliyuncs.com/google_containers   --kubernetes-version v1.28.0   --service-cidr=10.96.0.0/12   --pod-network-cidr=10.244.0.0/16   --cri-socket=unix:///var/run/cri-dockerd.sock
初始化完成后，根据提示信息，拷贝kubectl工具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

使用kubectl工具查看节点状态

~]# kubectl get nodes
NAME               STATUS     ROLES            AGE   VERSION
k8s-master     NotReady   control-plane        29s   v1.28.0

由于网络插件还没有部署，节点会处于“NotReady”状态，安装完Calico或者flannel再次查看才会获得节点和pod的状态。

节点加入集群

kubeadm join 192.168.88.10:6443 --token m1fjhe.oykxam4vxhzq9u5b \
	--discovery-token-ca-cert-hash sha256:07d4a0122be4a28ec7fb3f91d132b0dce583d44f9b6ebd81eecfdee3a443d2d4 --cri-socket=unix:///var/run/cri-dockerd.sock

本次搭建的集群节点加入集群出现报错

可能会出现此报错：[ERROR FileContent--proc-sys-net-ipv4-ip_forward]: /proc/sys/net/ipv4/ip_forward contents are not set to 1

执行echo 1 > /proc/sys/net/ipv4/ip_forward即可解决

标题安装网络插件

本次集群搭建使用的是flannel插件

flannel.yml内容如下：

apiVersion: v1
kind: Namespace
metadata:
  labels:
    k8s-app: flannel
    pod-security.kubernetes.io/enforce: privileged
  name: kube-flannel
---
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: flannel
  name: flannel
  namespace: kube-flannel
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: flannel
  name: flannel
rules:
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - nodes
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - ""
  resources:
  - nodes/status
  verbs:
  - patch
- apiGroups:
  - networking.k8s.io
  resources:
  - clustercidrs
  verbs:
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: flannel
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-flannel
---
apiVersion: v1
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"
      }
    }
kind: ConfigMap
metadata:
  labels:
    app: flannel
    k8s-app: flannel
    tier: node
  name: kube-flannel-cfg
  namespace: kube-flannel
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  labels:
    app: flannel
    k8s-app: flannel
    tier: node
  name: kube-flannel-ds
  namespace: kube-flannel
spec:
  selector:
    matchLabels:
      app: flannel
      k8s-app: flannel
  template:
    metadata:
      labels:
        app: flannel
        k8s-app: flannel
        tier: node
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      containers:
      - args:
        - --ip-masq
        - --kube-subnet-mgr
        command:
        - /opt/bin/flanneld
        command: ["/bin/bash", "-ce", "tail -f /dev/null"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        - name: EVENT_QUEUE_DEPTH
          value: "5000"
        image: registry.cn-hangzhou.aliyuncs.com/liuk8s/flannel:v0.21.5
        name: kube-flannel
        resources:
          requests:
            cpu: 100m
            memory: 50Mi
        securityContext:
          capabilities:
            add:
            - NET_ADMIN
            - NET_RAW
          privileged: false
        volumeMounts:
        - mountPath: /run/flannel
          name: run
        - mountPath: /etc/kube-flannel/
          name: flannel-cfg
        - mountPath: /run/xtables.lock
          name: xtables-lock
      hostNetwork: true
      initContainers:
      - args:
        - -f
        - /flannel
        - /opt/cni/bin/flannel
        command:
        - cp
        image: registry.cn-hangzhou.aliyuncs.com/liuk8s/flannel-cni-plugin:v1.1.2
        name: install-cni-plugin
        volumeMounts:
        - mountPath: /opt/cni/bin
          name: cni-plugin
      - args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        command:
        - cp
        image: registry.cn-hangzhou.aliyuncs.com/liuk8s/flannel:v0.21.5
        name: install-cni
        volumeMounts:
        - mountPath: /etc/cni/net.d
          name: cni
        - mountPath: /etc/kube-flannel/
          name: flannel-cfg
      priorityClassName: system-node-critical
      serviceAccountName: flannel
      tolerations:
      - effect: NoSchedule
        operator: Exists
      volumes:
      - hostPath:
          path: /run/flannel
        name: run
      - hostPath:
          path: /opt/cni/bin
        name: cni-plugin
      - hostPath:
          path: /etc/cni/net.d
        name: cni
      - configMap:
          name: kube-flannel-cfg
        name: flannel-cfg
      - hostPath:
          path: /run/xtables.lock
          type: FileOrCreate
        name: xtables-lock