linux安装k8s环境初始化
一、基础环境配置
1、检查操作系统版本
# 此方式要求k8s集群要求在centos7.5版本或者以上版本
[root@k8s-master /]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
2、主机名解析
为了方便后面集群间的直接调用，配置主机名解析
[root@k8s-master /]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.174.128 k8s-master
192.168.174.129 k8s-node1
192.168.174.130 k8s-node23、时间同步
k8s要求集群中的节点时间必须精确一致，这里使用chronyd服务从网络同步时间# 启动chronyd服务
# 启动服务
[root@k8s-master /]# systemctl start chronyd
# 设置服务自启动
[root@k8s-master /]# systemctl enable chronyd
# 查看时间
[root@k8s-master /]# date
2021年 09月 17日 星期五 15:55:26 CST
4、禁用iptables和firewalld服务
k8s运行中会产生大量的iptable规则，避免规则混淆，直接关闭系统原则
[root@k8s-master /]# systemctl stop firewalld
[root@k8s-master /]# systemctl disable firewalld
[root@k8s-master /]# systemctl stop iptables
[root@k8s-master /]# systemctl disable iptables5、禁用selinux
selinux是linux系统的一个安全服务，如果不关闭将造成集群各种问题
# 编辑、/etc/selinux/config 文件
# 修改之后需要重启服务
SELINUX=disabled6、禁用swap分区
# 编辑分区配置文件 etc/fstab ，注释掉swap分区这一行
[root@k8s-node2 /]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Mon May 24 05:53:45 2021
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=34218ca8-2e15-49b3-86d7-2493ae5c58ae /boot xfs defaults 0 0
# /dev/mapper/centos-swap swap swap defaults 0 07、修改linux内核参数
# 修改（添加）linux内核参数，天机网桥过滤和地址转发功能# 编辑 vim etc/sysctl.d/kubernetes.conf
[root@k8s-master /]# vim etc/sysctl.d/kubernetes.conf
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
# 重新加载配置
[root@k8s-master /]# sysctl -p
#加载网桥过滤模块
[root@k8s-master /]# modprobe br_netfilter
# 查看网桥过滤模块是否加载成功
[root@k8s-master /]# lsmod | grep br_netfilter
br_netfilter 22256 0
bridge 151336 1 br_netfilter
8、配置ipvs功能
k8s配置使用ipvs为代理
# 1、安装upset和ipvsadmin
yum install ipset ipvsadm -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、为脚本添加权限
chmod +x /etc/sysconfig/modules/ipvs.modules
# 4、执行脚本
/bin/bash /etc/sysconfig/modules/ipvs.modules
# 5、查看对应模块是否加载成功
grep -e ip_vs -e nf_conntrack_ipv49、重启服务
reboot10、安装docker切换镜像
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
1、査看当前镜像源中支持的docker版本
yum list docker-ce --showduplicates
2、安装特定版本的docker-ce
#必须指定--setopt=obsoletes=0,否则yum#自动安装更高版本
yum install docker-ce-19.03.15-3.el7
3、 添加一个配件
# Docker在默认情况下使用的Cgroup Driver为cgroupfs,而kubernetes荐庚用systemd来代曾cgroupfs
# mkdir /etc/docker
cat<<EOF > /etc/docker/daemon.json
{
"registry-mirrors": [
"https://kfwkfulq.mirror.aliyuncs.com",
"https://2lqq34jg.mirror.aliyuncs.com",
"https://pee6w651.mirror.aliyuncs.com",
"https://registry.docker-cn.com",
"http://hub-mirror.c.163.com"],
"exec-opts":["native.cgroupdriver=systemd"]
}
EOF
# 5 后动docker
# systemctl restart docker11、安装k8s组件
# 由于kubernetes的镜像源在国外，速度比较慢，这里切换成国内的镜像源 # 编辑 /etc/yum.repos.d/kubernetes.repo，添加下面的配置 cat <<EOF > /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 # 安装kubeadnu kubelet和kubectl(制定版本) # yum install --setopt=obsoletes=0 kubeadm-1.17.4 kubelet-1.17.4 kubectl-1.17.4 -y
#安装最新版本,也可安装指定版本
yum install -y kubelet kubeadm kubectl
#查看kubelet版本
kubelet--version
#查看kubeadm版本
kubeadm version#重新加载配置文件
systemctl daemon-reload
#启动kubelet
systemctl start kubelet
#查看kubelet启动状态
systemctl status kubelet
#没启动成功,报错先不管,后面的kubeadm init会拉起
#设置开机自启动
systemctl enable kubelet
#查看kubelet开机启动状态 enabled:开启, disabled:关闭
systemctl is-enabled kubelet
#查看日志
journalctl -xefu kubelet# 配置 kubelet的cgroup # 编辑 /etc/sysconfig/kubelet，添加下面的配置 KUBELET_CGROUP_ARGS="--cgroup-driver=systemd" KUBE_PROXY_MODE="ipvs" # 设置kubelet幵机自启 # systemctl enable kubelet
二、集群初始化
1、准备镜像文件
#查看k8s组件版本
kubeadm config images list
#通过国内镜像仓库下载所需的镜像文件 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.17.4 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.17.4 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.17.4 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.17.4 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.5 #更改镜像名称 docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.17.4 k8s.gcr.io/kube-apiserver:v1.17.4 docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.17.4 k8s.gcr.io/kube-controller-manager:v1.17.4 docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.17.4 k8s.gcr.io/kube-scheduler:v1.17.4 docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.17.4 k8s.gcr.io/kube-proxy:v1.17.4 docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1 docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0 k8s.gcr.io/etcd:3.4.3-0 docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.5 k8s.gcr.io/coredns:1.6.5 #删除原先的镜像 docker image rm registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.17.4 docker image rm registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.17.4 docker image rm registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.17.4 docker image rm registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.17.4 docker image rm registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 docker image rm registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0 docker image rm registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.5
2、初始化集群（master节点）
#执行初始化命令，创建集群
kubeadm init --kubernetes-version v1.17.4 --pod-network-cidr 10.244.0.0/16 --ignore-preflight-errors=NumCPU
#创建必要的文件
mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config
#查看节点
kubectl get node 
初始化错误解决办法：
#删除文件 /var/lib/kubelet/kubeadm-flags.env /var/lib/kubelet/config.yaml /etc/kubernetes #执行脚本 swapoff -a kubeadm reset systemctl daemon-reload systemctl restart kubelet iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
# 重新执行初始化脚本
3、node节点加入集群（node节点）
kubeadm join 192.168.174.128:6443 --token x818xi.jzxi4utggs081p71 \
--discovery-token-ca-cert-hash sha256:b6e3b74bf2eb2c7dce03225b1993a03f747700c74cc75b6b1dea9712bdc3cdfa
4、安装网络插件（master节点）
#创建文件夹 mkdir flannel && cd flannel #下载文件 curl -O https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml # kube-flannel.yml里需要下载镜像,我这里提前先下载 docker pull quay.io/coreos/flannel:v0.14.0-rc1 #创建flannel网络插件 kubectl apply -f kube-flannel.yml #过一会查看k8s集群节点,变成Ready状态了 kubectl get nodes
[root@k8s-master flannel]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 21m v1.17.4
k8s-node1 Ready <none> 4m37s v1.17.4
k8s-node2 Ready <none> 17m v1.17.4
搞定，但是 raw.githubusercontent.com已经被墙了，这里放上kube-flannel.yml文件的源码
cat <<EOF > 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'] 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.io/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.io/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.io/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.io/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.io/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.io/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.io/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.io/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.io/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.io/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 EOF
5、服务验证(部署一个nginx服务)
#部署nginx kubectl create deployment nginx --image=nginx:1.14-alpine #暴露端口 kubectl expose deployment nginx --port=80 --type=NodePort #查看服务状态 kubectl get pod
kubectl get service/svc
6、k8s版本问题解决办法
[ERROR KubeletVersion]: the kubelet version is higher than the control plane version. This is not a supported version skew and may lead to a malfunctional cluster
原因：
Kubelet 和 Kubeadm 版本不一致导致
查看kubelet 和 kubeadm 版本
[root@k8s-master01 cluster]# kubelet --version
Kubernetes v1.19.3
[root@k8s-master01 cluster]# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.0", GitCommit:"641856db18352033a0d96dbc99153fa3b27298e5", GitTreeState:"clean", BuildDate:"2019-03-25T15:51:21Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}
[root@k8s-master01 cluster]#
解决办法：
重新安装对应的 kubelet 版本
yum -y remove kubelet yum -y install kubelet-1.14.0 kubeadm-1.14.0 kubectl-1.14.0 --disableexcludes=kubernetes
启动服务
systemctl enable kubelet && systemctl restart kubelet
