Kubernetes 安装

dingding • • 杂文

K8S 安装

环境要求

  1. 服务器：Centos7 2核2G内存

节点规划

节点 配置 说明
master 2c 2G master 节点
k8swork1 2c 2G work 节点

服务器环境准备

  1. 配置服务器主机名(各主机的服务器时间要同步)

    # master节点
vi /etc/hostname 
设置成 master
# work 节点
vi /etc/hostname
设置成 k8swork1

  2. 防火墙设置

    sed -i "s/^SELINUX/=enforcing/SELINUX/=disabled/g" /etc/selinux/config
setenforce 0 
systemctl stop firewalld
systemctl disable firewalld

  3. 关闭swap

    sed -i '/ swap / s/^/(.*/)$/#/1/g' /etc/fstab

  4. 内核参数设置

    echo "net.bridge.bridge-nf-call-ip6tables = 1" >>/etc/sysctl.conf
echo "net.bridge.bridge-nf-call-iptables = 1" >> /etc/sysctl.conf
echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf 
sysctl -p

  5. 仓库配置(可复制到其他机器)

    5.1 备份旧的配置

    cd /etc/yum.repos.d/
mkdir bak
mv *.repo bak

    5.2 下载阿里云仓库

    cd /etc/yum.repos.d/
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

    5.3 下载kubernetes yaml 文件

    cd /etc/yum.repos.d/
cat < /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

  6. docker 配置

    # 安装docker
yum install -y docker 
# 设置docker 开机自动启动
systemctl enable docker.service
# 启动docker
service docker restart

安装k8s组件

  1. 安装组件

    yum install -y kubelet kubeadm kubectl kubernetes-cni

  2. 因为k8s的组件在启动时，会依赖于 gcr.io 下的很多镜像，国内访问不了，先提前下载这些镜像

    # 可以通过以下命令来看 依赖的几个组件的版本要求
kubeadm config images list

    # 输出以下内容
k8s.gcr.io/kube-apiserver:v1.18.20
k8s.gcr.io/kube-controller-manager:v1.18.20
k8s.gcr.io/kube-scheduler:v1.18.20
k8s.gcr.io/kube-proxy:v1.18.20
k8s.gcr.io/pause:3.2
k8s.gcr.io/etcd:3.4.3-0
k8s.gcr.io/coredns:1.6.7

  3. 因为访问不了外网，可以从dockerhub 上搜索对应的组件进行使用

    docker pull gotok8s/kube-apiserver:v1.18.5
docker pull gotok8s/kube-controller-manager:v1.18.5
docker pull gotok8s/kube-scheduler:v1.18.5
docker pull gotok8s/kube-proxy:v1.18.5
docker pull gotok8s/pause:3.2
docker pull gotok8s/etcd:3.4.3-0
docker pull gotok8s/coredns:1.6.7

docker tag docker.io/gotok8s/kube-proxy:v1.18.5 k8s.gcr.io/kube-apiserver:v1.18.20
docker tag docker.io/gotok8s/kube-controller-manager:v1.18.5 k8s.gcr.io/kube-controller-manager:v1.18.20
docker tag docker.io/gotok8s/kube-scheduler:v1.18.5 k8s.gcr.io/kube-scheduler:v1.18.20
docker tag docker.io/gotok8s/coredns:1.6.7 k8s.gcr.io/coredns:1.6.7
docker tag docker.io/gotok8s/etcd:3.4.3-0 k8s.gcr.io/etcd:3.4.3-0
docker tag docker.io/gotok8s/pause:3.2 k8s.gcr.io/pause:3.2

  4. 开始通过 kubeadm 安装master

     kubeadm init --apiserver-advertise-address=192.168.136.133 --kubernetes-version v1.18.0 --service-cidr=10.1.0.0/16 --pod-network-cidr=10.244.0.0/16 --image-repository=registry.aliyuncs.com/google_containers

    如果没有异常的情况下，可以看到 master 创建好了

    但是正常是会有 master 处理 NotReady的情况，因为k8s有依赖于网络组件，会发现 coredns 组件一直是处于未启动的状态

  5. 安装 flannel

    5.1 下载 flannel.yaml 文件，可拷贝如下内容:

    ---
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/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": "10.168.0.0/16",
      "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: kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: kubernetes.io/arch
                    operator: In
                    values:
                      - amd64
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-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.io/coreos/flannel:v0.12.0-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", "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
---
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: kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: kubernetes.io/arch
                    operator: In
                    values:
                      - arm64
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-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.io/coreos/flannel:v0.12.0-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", "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
---
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: kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: kubernetes.io/arch
                    operator: In
                    values:
                      - arm
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-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.io/coreos/flannel:v0.12.0-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", "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
---
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: kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: kubernetes.io/arch
                    operator: In
                    values:
                      - ppc64le
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-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.io/coreos/flannel:v0.12.0-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", "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
---
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: kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: kubernetes.io/arch
                    operator: In
                    values:
                      - s390x
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-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.io/coreos/flannel:v0.12.0-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", "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

    5.2 执行安装

    kubectl apply -f flannel.yaml

    执行查看flannel 启动情况

    kubectl get pods --all-namespaces

    输出

    NAMESPACE     NAME                               READY   STATUS    RESTARTS   AGE
kube-system   coredns-7ff77c879f-fzfgj           1/1     Running   0          12h
kube-system   coredns-7ff77c879f-mc6h4           1/1     Running   0          12h
kube-system   etcd-master                        1/1     Running   0          12h
kube-system   kube-apiserver-master              1/1     Running   0          12h
kube-system   kube-controller-manager-master     1/1     Running   3          12h
kube-system   kube-flannel-ds-amd64-nc6wh        1/1     Running   0          11h
# flannel 是daemonset ，在所以节点都会启动
kube-system   kube-flannel-ds-amd64-nl59d        1/1     Running   0          11h
kube-system   kube-proxy-fg6l5                   1/1     Running   2          12h
kube-system   kube-proxy-ph5m6                   1/1     Running   0          12h
kube-system   kube-scheduler-master              1/1     Running   3    12h

  6. 至此，查看Node节点的状态

    [root@master deployment]# kubectl get nodes | grep master
master     Ready    master   12h   v1.18.0

  7. work 节点加入

    kubeadm join 192.168.136.133:6443 --token yy2huh.9e20jcil00z4rhwf     --discovery-token-ca-cert-hash sha256:3336bb808ec8b8f1d1482a52cbfee2f2cb8252b1902b7dcf83df191d1e7ca669

    注意：

    1. token 的生成

      在master 上 kubeadm token list 查看目前有效的token

      如果没有，通过 kubeadm token create 进行创建

    2. discovery-token-ca-cert-hash 如果没有，在master 上执行以下方式生成

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

    3. 如果加入后，work节点出现 NotReady的情况

      # 首先确认not ready 的原因
kubectl describe node k8swork1

      Conditions:
  Type                 Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----                 ------  -----------------                 ------------------                ------                       -------
  NetworkUnavailable   False   Tue, 14 Sep 2021 22:22:28 +0800   Tue, 14 Sep 2021 22:22:28 +0800   FlannelIsUp                  Flannel is running on this node
  MemoryPressure       False   Wed, 15 Sep 2021 09:50:21 +0800   Wed, 15 Sep 2021 09:24:39 +0800   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure         False   Wed, 15 Sep 2021 09:50:21 +0800   Wed, 15 Sep 2021 09:24:39 +0800   KubeletHasNoDiskPressure     kubelet has no disk pressure
  PIDPressure          False   Wed, 15 Sep 2021 09:50:21 +0800   Wed, 15 Sep 2021 09:24:39 +0800   KubeletHasSufficientPID      kubelet has sufficient PID available
  Ready                false    Wed, 15 Sep 2021 09:50:21 +0800   Wed, 15 Sep 2021 09:24:39 +0800   KubeletNotReady                 错误原因消息

      注：确认问题原因

      一般是因为在work 节点上不能下载flannel 镜像问题，导致网络异常

      通过在work节点上找到对应的容器，确认启动问题，而在本地测试的时候，是因为防火墙的问题，导致flannel在启动时出现异常

      重新设置下

      ## 如果已经按步骤下来，在环境准备第2步已经做了
vi /etc/selinux/config 
# 设置
SELINUX=disabled

  8. 查看节点状态

    kubectl get nodes

    [root@master deployment]# kubectl get nodes
NAME       STATUS   ROLES    AGE   VERSION
k8swork1   Ready       12h   v1.18.0
master     Ready    master   12h   v1.18.0

    通过以上，说明节点都已经Ready 状态

版权声明：
作者：dingding
链接：https://www.techfm.club/p/46593.html
来源：TechFM
文章版权归作者所有，未经允许请勿转载。

THE END
分享
二维码
< <上一篇
下一篇>>