CentOS安装k8s单机/集群及一些命令

目录

前言

1. 安装docker

2. 安装要求

3.准备网络（如果只装单机版可跳过此部）

4. 准备工作

5. 安装

5.1. 配置阿里云yum k8s源

5.2 安装kubeadm、kubectl和kubelet

5.3 初始化，只在master执行，子节点不要执行

5.3.1 一些错误（没有错误直接忽略）

5.4 使用kubectl工具

5.5 子节点加入（单机版可忽略）

5.6 部署CNI网络插件

6. 扩展

---

前言

        只针对1.24版本以前的k8s, 1.24版本以后删除了内置dockershim插件，原生不再支持docker运行时，需要使用第三方cri接口cri-docker

1. 安装docker

看我上一篇博客

CentOS安装docker及一些命令https://blog.csdn.net/o_CanDou6/article/details/135505341

2. 安装要求

• 内存大于等于2G，CPU大于等于2核，硬盘大于等于30G。
• 禁止swap分区。

3.准备网络（如果只装单机版可跳过此部）

新安装的Centos服务器需要配置静态网络：
打开网络配置文件：

vi /etc/sysconfig/network-scripts/ifcfg-enp0s3 

将以下内容添加进去，其中BOOTPROTO="static"表示静态网络，NAME和DEVICE填网卡驱动如果没有驱动需要手动安装即可；下面添加IP、子网掩码以及网关、DNS等内容。

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static #需要修改
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
NAME=enp0s3
UUID=5c84522d-4102-4260-9a23-4121bd510252
DEVICE=enp0s3
ONBOOT=yes
IPADDR=192.168.2.159 #修改固定ip
NETMASK=255.255.255.0 #同步修改
GATEWAY=192.168.2.1 #同步修改
DNS1=192.168.2.1 #同步修改

准备了两个虚拟机当做演示ip地址如下（按自己的ip为准）

角色	名称	IP
主节点	master	192.168.2.159
子节点	node1	192.168.2.64

4. 准备工作

#永久关闭防火墙
systemctl stop firewalld
systemctl disable firewalld#永久关闭swap
sed -ri 's/.*swap.*/#&/' /etc/fstab# 单机可以不执行如下命令
## 二台服务器设置主机名
hostnamectl set-hostname <hostname>## 修改hosts
vi /etc/hosts# 加入如下数据 按自己ip增加
192.168.2.159 master
192.168.2.64 node1

5. 安装

5.1. 配置阿里云yum k8s源

vi /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

可查看k8s版本信息

yum list kubelet --showduplicates | sort -r

我们以1.21.0版本为例 （注意k8s版本需要对于特定的docker版本，不然安装不成功）

以下是一些常见的k8s与Docker版本对应关系：

• k8s v1.22.x 对应 Docker 20.10.x
• k8s v1.21.x 对应 Docker 20.10.x
• k8s v1.20.x 对应 Docker 19.03.x

5.2 安装kubeadm、kubectl和kubelet

yum install -y kubelet-1.21.0 kubeadm-1.21.0 kubectl-1.21.0systemctl enable kubelet

5.3 初始化，只在master执行，子节点不要执行

# --apiserver-advertise-address=本机ip
kubeadm init --kubernetes-version=1.21.0 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=[本机ip] --ignore-preflight-errors=all --image-repository=registry.aliyuncs.com/google_containers

5.3.1 一些错误（没有错误直接忽略）

[WARNING FileExisting-tc]: tc not found in system path 错误

# 解决方法
yum install iproute-tc -y 

[WARNING ImagePull]: failed to pull image registry.aliyuncs.com/google_containers/coredns/coredns:v1.8.0: output: Error response from daemon: pull access denied for registry.aliyuncs.com/google_containers/coredns/coredns, repository does not exist or may require 'docker login': denied: requested access to the resource is denied
, error: exit status 1

# 解决方法
docker pull coredns/coredns:latest
docker tag coredns/coredns:latest registry.aliyuncs.com/google_containers/coredns/coredns:v1.8.0

5.4 使用kubectl工具

执行完毕后会出现如下内容红框内容在master（本机）上执行，蓝框的在子节点上执行加入集群

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

执行完可以查看节点了

kubectl get nodes

现在只有自己

5.5 子节点加入（单机版可忽略）

子节点不需要执行5.3 初始化的内容，只执行master输出的 kubeadm join 命令加入集群即可

# 执行自己的输出内容不要复制内容不同

kubeadm join 192.168.2.159:6443 --token e5doub.g27604rf65vj02yr \
        --discovery-token-ca-cert-hash sha256:2521d2d4ee37750feba14a00ef0de0dfc390b1141f7abda81b0e259ce01870af 

子节点执行完后再次查看节点

子节点加入进来了但是这时候子节点还不能使用，需要把master服务器/etc/kubernetes/admin.conf复制到子节点的/etc/kubernetes/文件夹中

然后再子节点中执行

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

现在子节点可以正常使用了

5.6 部署CNI网络插件

kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

访问不到的可以复制如下内容自己创建文件 使用 kubectl apply -f  执行

---
kind: Namespace
apiVersion: v1
metadata:name: kube-flannellabels:k8s-app: flannelpod-security.kubernetes.io/enforce: privileged
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:labels:k8s-app: flannelname: flannel
rules:
- apiGroups:- ""resources:- podsverbs:- get
- apiGroups:- ""resources:- nodesverbs:- get- list- watch
- apiGroups:- ""resources:- nodes/statusverbs:- patch
- apiGroups:- networking.k8s.ioresources:- clustercidrsverbs:- list- watch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:labels:k8s-app: flannelname: flannel
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: flannel
subjects:
- kind: ServiceAccountname: flannelnamespace: kube-flannel
---
apiVersion: v1
kind: ServiceAccount
metadata:labels:k8s-app: flannelname: flannelnamespace: kube-flannel
---
kind: ConfigMap
apiVersion: v1
metadata:name: kube-flannel-cfgnamespace: kube-flannellabels:tier: nodek8s-app: flannelapp: 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-dsnamespace: kube-flannellabels:tier: nodeapp: flannelk8s-app: flannel
spec:selector:matchLabels:app: flanneltemplate:metadata:labels:tier: nodeapp: flannelspec:affinity:nodeAffinity:requiredDuringSchedulingIgnoredDuringExecution:nodeSelectorTerms:- matchExpressions:- key: kubernetes.io/osoperator: Invalues:- linuxhostNetwork: truepriorityClassName: system-node-criticaltolerations:- operator: Existseffect: NoScheduleserviceAccountName: flannelinitContainers:- name: install-cni-pluginimage: docker.io/flannel/flannel-cni-plugin:v1.2.0command:- cpargs:- -f- /flannel- /opt/cni/bin/flannelvolumeMounts:- name: cni-pluginmountPath: /opt/cni/bin- name: install-cniimage: docker.io/flannel/flannel:v0.24.0command:- cpargs:- -f- /etc/kube-flannel/cni-conf.json- /etc/cni/net.d/10-flannel.conflistvolumeMounts:- name: cnimountPath: /etc/cni/net.d- name: flannel-cfgmountPath: /etc/kube-flannel/containers:- name: kube-flannelimage: docker.io/flannel/flannel:v0.24.0command:- /opt/bin/flanneldargs:- --ip-masq- --kube-subnet-mgrresources:requests:cpu: "100m"memory: "50Mi"securityContext:privileged: falsecapabilities:add: ["NET_ADMIN", "NET_RAW"]env:- name: POD_NAMEvalueFrom:fieldRef:fieldPath: metadata.name- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespace- name: EVENT_QUEUE_DEPTHvalue: "5000"volumeMounts:- name: runmountPath: /run/flannel- name: flannel-cfgmountPath: /etc/kube-flannel/- name: xtables-lockmountPath: /run/xtables.lockvolumes:- name: runhostPath:path: /run/flannel- name: cni-pluginhostPath:path: /opt/cni/bin- name: cnihostPath:path: /etc/cni/net.d- name: flannel-cfgconfigMap:name: kube-flannel-cfg- name: xtables-lockhostPath:path: /run/xtables.locktype: FileOrCreate

6. 扩展

在master安装 recommended.yaml 和 dashboard-adminuser.yml 使用图形界面查看 （这两个文件在下方）

kubectl apply -f recommended.yaml
kubectl apply -f dashboard-adminuser.yml 

安装完成后可以用火狐访问 https://[ip地址]:32508/#/login 如我的为 https://192.168.2.159:32508/#/login

注意不要用高版本Chrome或者edge登录https没有证书访问不了https://[ip地址]:32508/#/login 如我的为 

这里需要token执行下面命令获取token

# 获取登录凭证
kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin | awk '{print $1}')

粘贴后进入

recommended.yaml：

# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.apiVersion: v1
kind: Namespace
metadata:name: kubernetes-dashboard---apiVersion: v1
kind: ServiceAccount
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboardnamespace: kubernetes-dashboard---kind: Service
apiVersion: v1
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboardnamespace: kubernetes-dashboard
spec:type: NodePortports:- port: 443targetPort: 8443nodePort: 32508selector:k8s-app: kubernetes-dashboard---apiVersion: v1
kind: Secret
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboard-certsnamespace: kubernetes-dashboard
type: Opaque---apiVersion: v1
kind: Secret
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboard-csrfnamespace: kubernetes-dashboard
type: Opaque
data:csrf: ""---apiVersion: v1
kind: Secret
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboard-key-holdernamespace: kubernetes-dashboard
type: Opaque---kind: ConfigMap
apiVersion: v1
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboard-settingsnamespace: kubernetes-dashboard---kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboardnamespace: kubernetes-dashboard
rules:# Allow Dashboard to get, update and delete Dashboard exclusive secrets.- apiGroups: [""]resources: ["secrets"]resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs", "kubernetes-dashboard-csrf"]verbs: ["get", "update", "delete"]# Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.- apiGroups: [""]resources: ["configmaps"]resourceNames: ["kubernetes-dashboard-settings"]verbs: ["get", "update"]# Allow Dashboard to get metrics.- apiGroups: [""]resources: ["services"]resourceNames: ["heapster", "dashboard-metrics-scraper"]verbs: ["proxy"]- apiGroups: [""]resources: ["services/proxy"]resourceNames: ["heapster", "http:heapster:", "https:heapster:", "dashboard-metrics-scraper", "http:dashboard-metrics-scraper"]verbs: ["get"]---kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboard
rules:# Allow Metrics Scraper to get metrics from the Metrics server- apiGroups: ["metrics.k8s.io"]resources: ["pods", "nodes"]verbs: ["get", "list", "watch"]---apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboardnamespace: kubernetes-dashboard
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: kubernetes-dashboard
subjects:- kind: ServiceAccountname: kubernetes-dashboardnamespace: kubernetes-dashboard---apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:name: kubernetes-dashboard
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: kubernetes-dashboard
subjects:- kind: ServiceAccountname: kubernetes-dashboardnamespace: kubernetes-dashboard---kind: Deployment
apiVersion: apps/v1
metadata:labels:k8s-app: kubernetes-dashboardname: kubernetes-dashboardnamespace: kubernetes-dashboard
spec:replicas: 1revisionHistoryLimit: 10selector:matchLabels:k8s-app: kubernetes-dashboardtemplate:metadata:labels:k8s-app: kubernetes-dashboardspec:securityContext:seccompProfile:type: RuntimeDefaultcontainers:- name: kubernetes-dashboardimage: kubernetesui/dashboard:v2.5.1imagePullPolicy: Alwaysports:- containerPort: 8443protocol: TCPargs:- --auto-generate-certificates- --namespace=kubernetes-dashboard# Uncomment the following line to manually specify Kubernetes API server Host# If not specified, Dashboard will attempt to auto discover the API server and connect# to it. Uncomment only if the default does not work.# - --apiserver-host=http://my-address:portvolumeMounts:- name: kubernetes-dashboard-certsmountPath: /certs# Create on-disk volume to store exec logs- mountPath: /tmpname: tmp-volumelivenessProbe:httpGet:scheme: HTTPSpath: /port: 8443initialDelaySeconds: 30timeoutSeconds: 30securityContext:allowPrivilegeEscalation: falsereadOnlyRootFilesystem: truerunAsUser: 1001runAsGroup: 2001volumes:- name: kubernetes-dashboard-certssecret:secretName: kubernetes-dashboard-certs- name: tmp-volumeemptyDir: {}serviceAccountName: kubernetes-dashboardnodeSelector:"kubernetes.io/os": linux# Comment the following tolerations if Dashboard must not be deployed on mastertolerations:- key: node-role.kubernetes.io/mastereffect: NoSchedule---kind: Service
apiVersion: v1
metadata:labels:k8s-app: dashboard-metrics-scrapername: dashboard-metrics-scrapernamespace: kubernetes-dashboard
spec:ports:- port: 8000targetPort: 8000selector:k8s-app: dashboard-metrics-scraper---kind: Deployment
apiVersion: apps/v1
metadata:labels:k8s-app: dashboard-metrics-scrapername: dashboard-metrics-scrapernamespace: kubernetes-dashboard
spec:replicas: 1revisionHistoryLimit: 10selector:matchLabels:k8s-app: dashboard-metrics-scrapertemplate:metadata:labels:k8s-app: dashboard-metrics-scraperspec:securityContext:seccompProfile:type: RuntimeDefaultcontainers:- name: dashboard-metrics-scraperimage: kubernetesui/metrics-scraper:v1.0.7ports:- containerPort: 8000protocol: TCPlivenessProbe:httpGet:scheme: HTTPpath: /port: 8000initialDelaySeconds: 30timeoutSeconds: 30volumeMounts:- mountPath: /tmpname: tmp-volumesecurityContext:allowPrivilegeEscalation: falsereadOnlyRootFilesystem: truerunAsUser: 1001runAsGroup: 2001serviceAccountName: kubernetes-dashboardnodeSelector:"kubernetes.io/os": linux# Comment the following tolerations if Dashboard must not be deployed on mastertolerations:- key: node-role.kubernetes.io/mastereffect: NoSchedulevolumes:- name: tmp-volumeemptyDir: {}

dashboard-adminuser.yml:

apiVersion: v1
kind: ServiceAccount
metadata:name: admin-usernamespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:name: admin-userannotations:rbac.authorization.kubernetes.io/autoupdate: "true"
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: cluster-admin
subjects:
- kind: ServiceAccountname: admin-usernamespace: kube-system