kubernetes 环境搭建

1.一主多从: 在学习阶段我们只需要一台Master节点和多台Node节点，搭建简单,有单机发生故障风险，适合用于测试环境
2.多主多从:多台Master节点和多台Node节点，搭建有一些麻烦,安全系数高，适合用于生产环境

环境说明

• 1.基于云服务器构建kubernetes 环境

• 2.本地通过虚拟机构建kubernetes 环境 （当前方式）

安装Centos7.5 + 准备一个干净的，让后直接克隆三台虚拟机即可
启动虚拟机过程 ，建议分开的形式启动这三台虚拟机
注意：克隆了之后 记得一定要修改该linux服务器 mac地址

一、集群搭建方式

1.1、环境准备

1.一个主多个工作节点: 一台Master节点和多台Node节点，搭建简单,但是有单机故障风险，适合用于测试环境
2.多主节点多工作节点:多台Master节点和多台Node节点，搭建麻烦,安全性高，适合用于生产环境
程序员初学练习，采用一主多从即可
ip地址 类型 操作系统 服务配置
192.168.75.163 Master Centos7.6 2核CPU 2G内存 20G硬盘 （必需2核）
192.168.75.164 Node1 Centos7.6 2核CPU 2G内存 20G硬盘
192.168.75.165 Node2 Centos7.6 2核CPU 2G内存 20G硬盘

1.2、初始化环境

需要在这三台服务器上执行以下操作

1.检查操作系统的版本

 # 版本检查 Centos版本要在7.5或之上
 cat /etc/redhat-release 

2.主机名解析

主机名解析, 企业中推荐使用内部DNS服务器

# 开始编辑
vi /etc/hosts

# 主机名成解析
192.168.75.173  master
192.168.75.167  node1
192.168.75.175  node2

# 让后节点之间相互ping下是否配置成功
ping master
ping  node1
ping  node2

3.时间同步

kubernetes要求集群中的节点时间必须精确一致, 这里直接使用chronyd服务从网络同步时间。企业中建议配置内部的时间同步服务器

yum install -y chrony
systemctl start chronyd
systemctl enable chronyd

4.禁用iptables和firewalld服务

kubernetes和docker在运行中会产生大量的iptables规则，为了不让系统规则跟它们混淆，直接关闭系统的规则

# 关闭firewalld服务
systemctl stop firewalld
systemctl disable firewalld

# 关闭iptables服务
systemctl disabled iptables
systemctl disable iptables

5.关闭selinux

selinux是linux系统下的一个安全服务，如果不关闭它，在安装集群中会产生各种各样的奇葩问题,注意修改完毕之后需要重启 linux服务

# 开始编辑
vi /etc/selinux/config 

# 修改
SELINUX=disabled

6.禁用swap分区

swap分区指的是虚拟内存分区，它的作用是在物理内存使用完之后，将磁盘空间虚拟成内存来使用
启用swap设备会对系统的性能产生非常负面的影响，因此kubernetes要求每个节点都要禁用swap设备
但是如果因为某些原因确实不能关闭swap分区，就需要在集群安装过程中通过明确的参数进行配置说明
#编辑分区配置文件/etc/fstab,

vi /etc/fstab

# 注释掉swap分区一行  /dev/mapper/centos-swap swap....

7.修改Linux内核参数

修改linux的内核参数，添加网桥过滤和地址转发功能

# 编辑
vi /etc/sysctl.d/kubernetes.conf

# 添加配置
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1



# 重新加载配置
sysctl -p

#加载网桥过滤模块
modprobe br_netfilter

#查看网桥过滤模块是否加载成功
lsmod  | grep br_netfilter

8.配置ipvs功能

在kubernetes中service有两种代理模型，-种是基于iptables的, - -种是基于ipvs的
两者比较的话，ipvs的性能明显要高一些,但是如果要使用它，需要手动载入ipvs模块
k8s service 会使用 ipvs/iptables

# 1-安装ipset和ipvsadm
yum install ipset ipvsadmin -y

# 2-添加需要加载的模块写入脚本文件

cat <<EOF > /etc/sysconfig/modules/ipvs.modules
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF


# 3-为脚本文件添加执行权限
 chmod +x /etc/sysconfig/modules/ipvs.modules

# 4-执行脚本文件
sh +x /etc/sysconfig/modules/ipvs.modules

# 5-查看对应的模块是否加载成功
lsmod | grep -e ip_vs -e nf_conntrack_ipv4

9.重启Linux系统

reboot

二、安装 docker

1、安装docker

# 安装wget命令
yum -y install wget

# 切换镜像源
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo

# 查看 docker 源
yum list docker-ce --showduplicates

# 安装docker 18.06.3
yum install --setopt=obsoletes=0 docker-ce-18.06.3.ce-3.el7 -y

2、添加阿里云加速镜像 和 配置 cgroupdriver 为 cgroupdriver

## 创建配置文件
mkdir /etc/docker

## 如果存在所有
cd /etc/docker

## 修改文件配置
cat <<EOF > /etc/docker/daemon.json
{
"exec-opts": ["native.cgroupdriver=systemd"],
"registry-mirrors": [ "https://66mzqrih.mirror.aliyuncs.com"]
}
EOF

3、启动和设置为开机启动

systemctl start docker
systemctl enable docker

## 检查docker 版本
docker --version

三、安装kubernetes组件

1、切换由于kubernetes的镜像源为国内镜像源

vi  /etc/yum.repos.d/kubernetes.repo

[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
      http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg

2、安装kubeadm、kubelet和kubectl

yum install --setopt=obsoletes=0 kubeadm-1.17.4-0 kubelet-1.17.4-0 kubectl-1.17.4-0 -y

3、配置kubelet的cgroup

vi /etc/sysconfig/kubelet

# 追加内容
KUBELET_CGROUP_ARGS="--cgroup-driver=systemd"
KUBE_PROXY_MODE="ipvs"

4、设置kubelet开机自启

systemctl enable kubelet

5、安装kubernetes

准备集群镜像
在阿里云仓库中存在该镜像 在更改为k8s 官方的名称,同时需要在所有节点操作
#在安装k8s集群之前，必须要提前准备好集群需要的镜像，所需镜像可以通过下面命令查看

kubeadm config images list

2.下载镜像
#此镜像在k8s的仓库中,由于网络原因,无法连接，下面提供了-种替代方案
1、

images=(
kube-apiserver:v1.17.4
kube-controller-manager:v1.17.4
kube-scheduler:v1.17.4
kube-proxy:v1.17.4
pause:3.1
etcd:3.4.3-0 
coredns:1.6.5
)

2、开始下载

for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
done

3、 查看

docker images

6.1、集群- 主节点初始化

只需要在master节点上执行即可

• image-repository 需要更改为阿里云加速镜像
• apiserver-advertise-address 修改为主节点的ip

## 初始化
kubeadm init \
--kubernetes-version=v1.17.4 \
--pod-network-cidr=10.244.0.0/16 \
--image-repository registry.aliyuncs.com/google_containers \
--service-cidr=10.96.0.0/12 \
--apiserver-advertise-address=192.168.75.173

journalctl -xeu kubelet 查看日志

6.2、主节点初始化成功后子节点加入

初始化完成后拷贝该命令 到其他两个节点执行加入k8s集群环境

##  如果过期可以重新生成
kubeadm token create --ttl 0 --print-join-command

6.3、master与本机绑定 + 查看各节点

master 与本机绑定

## kubenetes master 与本机绑定，集群初始化时设置
export KUBECONFIG=/etc/kubernetes/admin.conf


## 查看各节点执行查看连接状态
kubectl get nodes

7.创建必要文件

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

8、网络插件安装

Master节点创建 kube-flannel.yml 文件
修改文件中quay.io仓库为quay-mirror.qiniu.com （已修改）

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 unsed 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: |
    {
      "cniVersion": "0.2.0",
      "name": "cbr0",
      "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

9、主从网络连接

网络插件

## 主从都执行
docker pull quay.io/coreos/flannel:v0.12.0-amd64

## master节执行
kubectl apply -f kube-flannel.yml

删除每台节点之前网络配置信息 network并重启服务

vi /var/lib/kubelet/kubeadm-flags.env

# 删除  --network-plugin=cni

# 重新启动每台节点
systemctl daemon-reload
systemctl restart kubelet

耐心等待30-60s 查看状态 是否为 ready状态

kubectl get nodes

整个k8s集群环境就搭建成功啦!

四、错误

重新初始化

kubeadm init 失败后，或kubeadm init 后重新问题，可使用 kubeadm reset 重置在重新初始化

kubeadm reset