CentOS中怎么搭建K8S

这篇文章将为大家详细讲解有关CentOS中怎么搭建K8S，文章内容质量较高，因此小编分享给大家做个参考，希望大家阅读完这篇文章后对相关知识有一定的了解。

环境：

•  操作系统：win10

•  虚拟机：virtual box

•  linux发行版：CentOS7

•  linux内核(使用uname -r查看)：3.10.0-957.el7.x86_64

•  master和node节点通信的ip(master)：192.168.99.104

二. 安装docker-ce 18.09.9（所有机器）

所有安装k8s的机器都需要安装docker，命令如下：

# 安装docker所需的工具  yum install -y yum-utils device-mapper-persistent-data lvm2  # 配置阿里云的docker源  yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo  # 指定安装这个版本的docker-ce  yum install -y docker-ce-18.09.9-3.el7 # 启动docker  systemctl enable docker && systemctl start docker

三. 设置k8s环境准备条件（所有机器）

安装k8s的机器需要2个CPU和2g内存以上，这个简单，在虚拟机里面配置一下就可以了。然后执行以下脚本做一些准备操作。所有安装k8s的机器都需要这一步操作。

# 关闭防火墙  systemctl disable firewalld  systemctl stop firewalld  # 关闭selinux  # 临时禁用selinux  setenforce 0  # 永久关闭 修改/etc/sysconfig/selinux文件设置  sed -i 's/SELINUX=permissive/SELINUX=disabled/' /etc/sysconfig/selinux  sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config  # 禁用交换分区  swapoff -a  # 永久禁用，打开/etc/fstab注释掉swap那一行。  sed -i 's/.*swap.*/#&/' /etc/fstab  # 修改内核参数  cat <<EOF >  /etc/sysctl.d/k8s.conf  net.bridge.bridge-nf-call-ip6tables = 1  net.bridge.bridge-nf-call-iptables = 1  EOF  sysctl --system

四. 安装k8s v1.16.0 master管理节点

如果还没安装docker，请参照本文步骤二安装docker-ce 18.09.9（所有机器）安装。如果没设置k8s环境准备条件，请参照本文步骤三设置k8s环境准备条件（所有机器）执行。

以上两个步骤检查完毕之后，继续以下步骤。

      1.   安装kubeadm、kubelet、kubectl

由于官方k8s源在google，国内无法访问，这里使用阿里云yum源

# 执行配置k8s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  # 安装kubeadm、kubectl、kubelet  yum install -y kubectl-1.16.0-0 kubeadm-1.16.0-0 kubelet-1.16.0-0  # 启动kubelet服务  systemctl enable kubelet && systemctl start kubelet

      2.  初始化k8s 以下这个命令开始安装k8s需要用到的docker镜像，因为无法访问到国外网站，所以这条命令使用的是国内的阿里云的源(registry.aliyuncs.com/google_containers)。另一个非常重要的是：这里的--apiserver-advertise-address使用的是master和node间能互相ping通的ip，我这里是192.168.99.104，刚开始在这里被坑了一个晚上，你请自己修改下ip执行。这条命令执行时会卡在[preflight] You can also perform this action in beforehand using ''kubeadm config images pull，大概需要2分钟，请耐心等待。

# 下载管理节点中用到的6个docker镜像，你可以使用docker images查看到  # 这里需要大概两分钟等待，会卡在[preflight] You can also perform this action in beforehand using ''kubeadm config images pull  kubeadm init --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.16.0 --apiserver-advertise-address 192.168.99.104 --pod-network-cidr=10.244.0.0/16 --token-ttl 0

上面安装完后，会提示你输入如下命令，复制粘贴过来，执行即可。

# 上面安装完成后，k8s会提示你输入如下命令，执行  mkdir -p $HOME/.kube  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config  sudo chown $(id -u):$(id -g) $HOME/.kube/config

      3.  记住node加入集群的命令 上面kubeadm init执行成功后会返回给你node节点加入集群的命令，等会要在node节点上执行，需要保存下来，如果忘记了，可以使用如下命令获取。

kubeadm token create --print-join-command

以上，安装master节点完毕。可以使用kubectl get nodes查看一下，此时master处于NotReady状态，暂时不用管。

五. 安装k8s v1.16.0 node工作节点

如果还没安装docker，请参照本文步骤二安装docker-ce 18.09.9（所有机器）安装。如果没设置k8s环境准备条件，请参照本文步骤三设置k8s环境准备条件（所有机器）执行。

以上两个步骤检查完毕之后，继续以下步骤。

      1.  安装kubeadm、kubelet

# 执行配置k8s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  # 安装kubeadm、kubectl、kubelet  yum install -y  kubeadm-1.16.0-0 kubelet-1.16.0-0  # 启动kubelet服务  systemctl enable kubelet && systemctl start kubelet

      2.  加入集群 这里加入集群的命令每个人都不一样，可以登录master节点，使用kubeadm token create --print-join-command 来获取。获取后执行如下。

# 加入集群，如果这里不知道加入集群的命令，可以登录master节点，使用kubeadm token create --print-join-command 来获取  kubeadm join 192.168.99.104:6443 --token ncfrid.7ap0xiseuf97gikl \      --discovery-token-ca-cert-hash sha256:47783e9851a1a517647f1986225f104e81dbfd8fb256ae55ef6d68ce9334c6a2

加入成功后，可以在master节点上使用kubectl get nodes命令查看到加入的节点。

六. 安装flannel（master机器）

以上步骤安装完后，机器搭建起来了，但状态还是NotReady状态，如下图，master机器需要安装flanneld。     

      1.  下载官方fannel配置文件 使用wget命令，地址为：(https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml)，这个地址国内访问不了，所以我把内容复制下来，为了避免前面文章过长，我把它粘贴到文章末尾第八个步骤附录了。这个yml配置文件中配置了一个国内无法访问的地址(quay.io)，我已经将其改为国内可以访问的地址(quay-mirror.qiniu.com)。我们新建一个kube-flannel.yml文件，复制粘贴该内容即可。

      2.  安装fannel

kubectl apply -f kube-flannel.yml

七. 大功告成

至此，k8s集群搭建完成，如下图节点已为Ready状态，大功告成，完结撒花。

八. 附录

这是kube-flannel.yml文件的内容，已经将无法访问的地址(quay.io)全部改为国内可以访问的地址(quay-mirror.qiniu.com)。我们新建一个kube-flannel.yml文件，复制粘贴该内容即可。

---  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']    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/v1beta1  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/v1beta1  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-amd64    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: beta.kubernetes.io/os                      operator: In                      values:                        - linux                    - key: beta.kubernetes.io/arch                      operator: In                      values:                        - amd64        hostNetwork: true        tolerations:        - operator: Exists          effect: NoSchedule        serviceAccountName: flannel        initContainers:        - name: install-cni          image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-amd64          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-mirror.qiniu.com/coreos/flannel:v0.11.0-amd64          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"]          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  ---  apiVersion: apps/v1  kind: DaemonSet  metadata:    name: kube-flannel-ds-arm64    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: beta.kubernetes.io/os                      operator: In                      values:                        - linux                    - key: beta.kubernetes.io/arch                      operator: In                      values:                        - arm64        hostNetwork: true        tolerations:        - operator: Exists          effect: NoSchedule        serviceAccountName: flannel        initContainers:        - name: install-cni          image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-arm64          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-mirror.qiniu.com/coreos/flannel:v0.11.0-arm64          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"]          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  ---  apiVersion: apps/v1  kind: DaemonSet  metadata:    name: kube-flannel-ds-arm    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: beta.kubernetes.io/os                      operator: In                      values:                        - linux                    - key: beta.kubernetes.io/arch                      operator: In                      values:                        - arm        hostNetwork: true        tolerations:        - operator: Exists          effect: NoSchedule        serviceAccountName: flannel        initContainers:        - name: install-cni          image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-arm          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-mirror.qiniu.com/coreos/flannel:v0.11.0-arm          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"]          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  ---  apiVersion: apps/v1  kind: DaemonSet  metadata:    name: kube-flannel-ds-ppc64le    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: beta.kubernetes.io/os                      operator: In                      values:                        - linux                    - key: beta.kubernetes.io/arch                      operator: In                      values:                        - ppc64le        hostNetwork: true        tolerations:        - operator: Exists          effect: NoSchedule        serviceAccountName: flannel        initContainers:        - name: install-cni          image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-ppc64le          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-mirror.qiniu.com/coreos/flannel:v0.11.0-ppc64le          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"]          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  ---  apiVersion: apps/v1  kind: DaemonSet  metadata:    name: kube-flannel-ds-s390x    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: beta.kubernetes.io/os                      operator: In                      values:                        - linux                    - key: beta.kubernetes.io/arch                      operator: In                      values:                        - s390x        hostNetwork: true        tolerations:        - operator: Exists          effect: NoSchedule        serviceAccountName: flannel        initContainers:        - name: install-cni          image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-s390x          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-mirror.qiniu.com/coreos/flannel:v0.11.0-s390x          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"]          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

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