K8s Kubernetes集群部署
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[root@master ~]# yum -y install docker-ce
[root@master ~]# systemctl enable --now docker
Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /usr/lib/systemd/system/docker.service.
[root@master ~]# docker --version
Docker version 20.10.12, build e91ed57
[root@master ~]# ls /etc/docker/
key.json
//镜像加速
[root@master ~]# cat > /etc/docker/daemon.json << EOF
“registry-mirrors”: [“https://b9pmyelo.mirror.aliyuncs.com”],
“exec-opts”: [“native.cgroupdriver=systemd”],
“log-driver”: “json-file”,
“log-opts”:
“max-size”: “100m”
,
“storage-driver”: “overlay2”
EOF
[](()添加kubernetes阿里云YUM软件源
[root@master ~]# cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
[root@master ~]# yum clean all && yum makecache
[](()安装kubeadm,kubelet和kubectl
//安装kubeadm,kubelet和kubectl,由于版本更新频繁,这里指定版本号部署
[root@master ~]# yum install -y kubelet-1.20.0 kubeadm-1.20.0 kubectl-1.20.0
[root@master ~]# systemctl enable kubelet
Created symlink /etc/systemd/system/multi-user.target.wants/kubelet.service → /usr/lib/systemd/system/kubelet.service.
[root@master ~]# systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled; vendor preset: disabled)
Drop-In: /usr/lib/systemd/system/kubelet.service.d
└─10-kubeadm.conf
Active: inactive (dead)
Docs: https://kubernetes.io/docs/
[](()部署Kubernetes Master
[root@master ~]# kubeadm init --apiserver-advertise-address 192.168.129.250 --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.20.0 --service-cidr 10.96.0.0/12 --pod-network-cidr 10.244.0.0/16
[init] Using Kubernetes version: v1.20.0
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected “cgroupfs” as the Docker cgroup driver. The recommended driver is “systemd”. Please follow the guide at https://kubernetes.io/docs/setup/cri/
[WARNING FileExisting-tc]: tc not found in system path
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.12. Latest validated version: 19.03
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using ‘kubeadm config images pull’
[certs] Using certificateDir folder “/etc/kubernetes/pki”
[certs] Generating “ca” certificate and key
[certs] Generating “apiserver” certificate and key
[certs] apiserver serving cert is signed for DNS names [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local master] and IPs [10.96.0.1 192.168.129.250]
[certs] Generating “apiserver-kubelet-client” certificate and key
[certs] Generating “front-proxy-ca” certificate and key
[certs] Generating “front-proxy-client” certificate and key
[certs] Generating “etcd/ca” certificate and key
[certs] Generating “etcd/server” certificate and key
[certs] etcd/server serving cert is signed for DNS names [localhost master] and IPs [192.168.129.250 127.0.0.1 ::1]
[certs] Generating “etcd/peer” certificate and key
[certs] etcd/peer serving cert is signed for DNS names [localhost master] and IPs [192.168.129.250 127.0.0.1 ::1]
[certs] Generating “etcd/healthcheck-client” certificate and key
[certs] Generating “apiserver-etcd-client” certificate and key
[certs] Generating “sa” key and public key
[kubeconfig] Using kubeconfig folder “/etc/kubernetes”
[kubeconfig] Writing “admin.conf” kubeconfig file
[kubeconfig] Writing “kubelet.conf” kubeconfig file
[kubeconfig] Writing “controller-manager.conf” kubeconfig file
[kubeconfig] Writing “scheduler.conf” kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file “/var/lib/kubelet/kubeadm-flags.env”
[kubelet-start] Writing kubelet configuration to file “/var/lib/kubelet/config.yaml”
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder “/etc/kubernetes/manifests”
[control-plane] Creating static Pod manifest for “kube-apiserver”
[control-plane] Creating static Pod manifest for “kube-controller-manager”
[control-plane] Creating static Pod manifest for “kube-scheduler”
[etcd] Creating static Pod manifest for local etcd in “/etc/kubernetes/manifests”
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory “/etc/kubernetes/manifests”. This can take up to 4m0s
[apiclient] All control plane components are healthy after 8.506240 seconds
[upload-config] Storing the configuration used in ConfigMap “kubeadm-config” in the “kube-system” Namespace
[kubelet] Creating a ConfigMap “kubelet-config-1.20” in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node master as control-plane by adding the labels “node-role.kubernetes.io/master=‘’” and “node-role.kubernetes.io/control-plane=‘’ (deprecated)”
[mark-control-plane] Marking the node master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: akxmi3.rtm7hjgs7n9trljm
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the “cluster-info” ConfigMap in the “kube-public” namespace
[kubelet-finalize] Updating “/etc/kubernetes/kubelet.conf” to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
Your Kubernetes control-plane has initialized successfully!
To start using your cluster, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown ( i d − u ) : (id -u): (id−u):(id -g) $HOME/.kube/config
Alternatively, if you are the root user, you can run:
export KUBECONFIG=/etc/kubernetes/admin.conf
You should now deploy a pod network to the cluster.
Run “kubectl apply -f [podnetwork].yaml” with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
Then you can join any number of worker nodes by running the following on each as root:
#下面的命令写到文件保存起来
kubeadm join 192.168.129.250:6443 --token hglo7o.0ya3tbi82wqdjif4 \\
–discovery-token-ca-cert-hash sha256:f6be891c6cd273a9283a6c05ca795811f7350afa2b5072990a294b7070ff9a4f
//把那条命令写入到文件中保存起来(以防万一)
[root@master ~]# vim init
kubeadm join 192.168.129.250:6443 --token hglo7o.0ya3tbi82wqdjif4 \\
–discovery-token-ca-cert-hash sha256:f6be891c6cd273a9283a6c05ca795811f7350afa2b5072990a294b7070ff9a4f
[root@master ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
registry.aliyuncs.com/google_containers/kube-proxy v1.20.0 10cc881966cf 12 months ago 118MB
registry.aliyuncs.com/google_containers/kube-scheduler v1.20.0 3138b6e3d471 12 months ago 46.4MB
registry.aliyuncs.com/google_containers/kube-apiserver v1.20.0 ca9843d3b545 12 months ago 122MB
registry.aliyuncs.com/google_containers/kube-controller-manager v1.20.0 b9fa1895dcaa 12 months ago 116MB
registry.aliyuncs.com/google_containers/etcd 3.4.13-0 0369cf4303ff 15 months ago 253MB
registry.aliyuncs.com/google_containers/coredns 1.7.0 bfe3a36ebd25 18 months ago 45.2MB
registry.aliyuncs.com/google_containers/pause 3.2 80d28bedfe5d 22 months ago 683kB
//设置环境变量
[root@master ~]# echo ‘export KUBECONFIG=/etc/kubernetes/admin.conf’ > /etc/profile.d/k8s.sh
[root@master ~]# source /etc/profile.d/k8s.sh
[root@master ~]# echo $KUBECONFIG
/etc/kubernetes/admin.conf
[root@master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready control-plane,master 76m v1.20.0 #要Ready(时间会有点长)
[](()安装Pod网络插件(CNI)
[root@master ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
The connection to the server raw.githubusercontent.com was refused - did you specify the right host or port? #出现此报错
//解决方案
[root@master ~]# cat /etc/hosts //添加如下内容
199.232.96.133 raw.githubusercontent.com
[root@master ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created
确保能访问到这个网站
[quay.io](()
[](()加入Kubernetes Node
在node1与node2节点上执行
向集群添加新节点,执行在kubeadm init输出的kubeadm join命令:
//这里执行的就是我们刚才保存的init文件里面的内容
[root@node1 ~]# kubeadm join 192.168.129.250:6443 --token hglo7o.0ya3tbi82wqdjif4 --discovery-token-ca-cert-hash sha256:f6be891c6cd273a9283a6c05ca795811f7350afa2b5072990a294b7070ff9a4f
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected “cgroupfs” as the Docker cgroup driver. The recommended driver is “systemd”. Please follow the guide at https://kubernetes.io/docs/setup/cri/
[WARNING FileExisting-tc]: tc not found in system path
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.12. Latest validated version: 19.03
[WARNING Hostname]: hostname “node1” could not be reached
[WARNING Hostname]: hostname “node1”: lookup node1 on 192.168.129.2:53: no such host
[preflight] Reading configuration from the cluster…
[preflight] FYI: You can look at this config file with ‘kubectl -n kube-system get cm kubeadm-config -o yaml’
[kubelet-start] Writing kubelet configuration to file “/var/lib/kubelet/config.yaml”
[kubelet-start] Writing kubelet environment file with flags to file “/var/lib/kubelet/kubeadm-flags.env”
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap…
This node has joined the cluster:
-
Certificate signing request was sent to apiserver and a response was received.
-
The Kubelet was informed of the new secure connection details.
Run ‘kubectl get nodes’ on the control-plane to see this node join the cluster.
// 在node2上执行
[root@node2 ~]# kubeadm join 192.168.129.250:6443 --token hglo7o.0ya3tbi82wqdjif4 --discovery-token-ca-cert-hash sha256:f6be891c6cd273a9283a6c05ca795811f7350afa2b5072990a294b7070ff9a4f
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected “cgroupfs” as the Docker cgroup driver. The recommended driver is “systemd”. Please follow the guide at https://kubernetes.io/docs/setup/cri/
[WARNING FileExisting-tc]: tc not found in system path
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.12. Latest validated version: 19.03
[WARNING Hostname]: hostname “node2” could not be reached
[WARNING Hostname]: hostname “node2”: lookup node2 on 114.114.114.114:53: no such host
[preflight] Reading configuration from the cluster…
[preflight] FYI: You can look at this config file with ‘kubectl -n kube-system get cm kubeadm-config -o yaml’
[kubelet-start] Writing kubelet configuration to file “/var/lib/kubelet/config.yaml”
[kubelet-start] Writing kubelet environment file with flags to file “/var/lib/kubelet/kubeadm-flags.env”
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap…
This node has joined the cluster:
-
Certificate signing request was sent to apiserver and a response was received.
-
The Kubelet was informed of the new secure connection details.
Run ‘kubectl get nodes’ on the control-plane to see this node join the cluster.
[](()测试kubernetes集群
// 查看节点的状态
[root@master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready control-plane,master 80m v1.20.0
node1 NotReady 69s v1.20.0 #等待状态变为Ready
node2 NotReady 52s v1.20.0 #等待状态变为Ready
[root@master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready control-plane,master 86m v1.20.0
node1 Ready 6m17s v1.20.0
node2 Ready 6m v1.20.0
[root@master ~]# kubectl get ns
NAME STATUS AGE
default Active 89m
kube-node-lease Active 89m
kube-public Active 89m
kube-system Active 89m
[root@master ~]# kubectl get pods -n kube-system -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
coredns-7f89b7bc75-qjjmz 1/1 Running 0 91m 10.244.0.3 master
coredns-7f89b7bc75-rvcdl 1/1 Running 0 91m 10.244.0.2 《一线大厂Java面试题解析+后端开发学习笔记+最新架构讲解视频+实战项目源码讲义》无偿开源 威信搜索公众号【编程进阶路】 master
etcd-master 1/1 Running 0 91m 192.168.129.250 master
kube-apiserver-master 1/1 Running 0 91m 192.168.129.250 master
kube-controller-manager-master 1/1 Running 0 91m 192.168.129.250 master
kube-flannel-ds-7stlz 1/1 Running 0 12m 192.168.129.135 node1
kube-flannel-ds-7xthp 1/1 Running 0 58m 192.168.129.250 master
kube-flannel-ds-mzw2x 1/1 Running 0 11m 192.168.129.136 node2
kube-proxy-b8qnc 1/1 Running 0 91m 192.168.129.250 master
kube-proxy-gr294 1/1 Running 0 12m 192.168.129.135 node1
kube-proxy-mtgnd 1/1 Running 0 11m 192.168.129.136 node2
kube-scheduler-master 1/1 Running 0 91m 192.168.129.250 master
[root@master ~]# kubectl create deployment nginx --image=nginx //运行一个nginx的pod
deployment.apps/nginx created
[root@master ~]# kubectl expose deployment nginx --port=80 --type=NodePort //映射80端口
service/nginx exposed
[root@master ~]# kubectl get pods,svc
NAME READY STATUS RESTARTS AGE
pod/nginx-6799fc88d8-8hwr2 0/1 ContainerCreating 0 33s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 443/TCP 87m
service/nginx NodePort 10.111.93.135 80:30274/TCP 24s
[root@master ~]# curl http://10.111.93.135
Kubernetes——Kubernetes基础+部署Kubernetes集群
Kubernetes基础+部署Kubernetes集群
Kubernetes介绍
1.1 应用部署方式演变
在部署应用程序的方式上,主要经历了三个时代:
- 传统部署:互联网早期,会直接将应用程序部署在物理机上
优点:简单,不需要其它技术的参与
缺点:不能为应用程序定义资源使用边界,很难合理地分配计算资源,而且程序之间容易产生影响
- 虚拟化部署:可以在一台物理机上运行多个虚拟机,每个虚拟机都是独立的一个环境
优点:程序环境不会相互产生影响,提供了一定程度的安全性
缺点:增加了操作系统,浪费了部分资源
- 容器化部署:与虚拟化类似,但是共享了操作系统
优点:
可以保证每个容器拥有自己的文件系统、CPU、内存、进程空间等
运行应用程序所需要的资源都被容器包装,并和底层基础架构解耦
容器化的应用程序可以跨云服务商、跨Linux操作系统发行版进行部署
- 容器化部署方式给带来很多的便利,但是也会出现一些问题,比如说:
- 一个容器故障停机了,怎么样让另外一个容器立刻启动去替补停机的容器
- 当并发访问量变大的时候,怎么样做到横向扩展容器数量
- 这些容器管理的问题统称为容器编排问题,为了解决这些容器编排问题,就产生了一些容器编排的软件:
Swarm
: Docker自己的容器编排工具Mesos
: Apache的一个资源统—管控的工具,需要和Marathon结合使用- Kubernetes : Google开源的的容器编排工具
1.2 Kubernetes简介
- kubernetes,是一个全新的基于容器技术的分布式架构领先方案,是谷歌严格保密十几年的秘密武器–
Borg
系统的一个开源版本,于2014年9月发布第一个版本,2015年7月发布第一个正式版本。 - kubernetes的本质是一组服务器集群,它可以在集群的每个节点上运行特定的程序,来对节点中的容器进行管理。它的目的就是是实现资源管理的自动化,主要提供了如下的主要功能:
- 自我修复:一旦某一个容器崩溃,能够在1秒中左右迅速启动新的容器
- 弹性伸缩:可以根据需要,自动对集群中正在运行的容器数进行调整
- 服务发现:服务可以通过自动发现的形式找到它所依赖的服务
- 负载均衡:如果一个服务起动了多个容器,能够自动实现请求的负载均衡
- 版本回退:如果发现新发布的程序版本有问题。可以立即回退到原来的版本
- 存储编排:可以根据容器自身的需求自动创建存储卷
1.3 Kubernetes组件
一个kubernetes集群主要是由控制节点
(master)、工作节点
(node)构成,每个节点上都会安装不同的组件。
- Master:集群的控制平面,负责集群的决策
ApiServer
:资源操作的唯一入口,接收用户输入的命令,提供认证、授权、API注册和发现等机制
Scheduler
:负责集群资源调度,按照预定的调度策略将Pod调度到相应的node节点上
ControllerManager
:负责维护集群的状态,比如程序部署安排、故障检测、自动扩展、滚动更新等
Etcd
:负责存储集群中各种资源对象的信息
- Node:集群的数据平面,负责为容器提供运行环境
Kubelet
:负责维护容器的生命周期,即通过控制docker,来创建、更新、销毁容器
KubeProxy
:负责提供集群内部的服务发现和负载均衡
Docker
:负责节点上容器的各种操作
- 部署一个nginx服务来说明kubernetes系统各个组件调用关系:
- 首先要明确,一旦kubernetes环境启动之后,master和node都会将自身的信息存储到
etcd
数据库中 - 一个nginx服务的安装请求会首先被发送到
master
节点的apiServer组件 apiServer
组件会调用scheduler组件来决定到底应该把这个服务安装到哪个node节点上,在此时,它会从etcd中读取各个node节点的信息,然后按照一定的算法进行选择,并将结果告知apiServer
apiServer
调用controller-manager去调度Node节点安装nginx服务kubelet
接收到指令后,会通知docker,然后由docker来启动一个nginx的pod
,pod是kubernetes的最小操作单元,容器必须跑在pod中至此- 一个nginx服务就运行了,如果需要访问nginx,就需要通过
kube-proxy
来对pod产生访问的代理,这样,外界用户就可以访问集群中的nginx服务了
- 首先要明确,一旦kubernetes环境启动之后,master和node都会将自身的信息存储到
1.4 Kubernetes概念
- Master:集群控制节点,每个集群需要至少一个master节点负责集群的管控
- Node:工作负载节点,由master分配容器到这些node工作节点上,然后node节点上的docker负责容器的运行
- Pod:kubernetes的最小控制单元,容器都是运行在pod中的,一个pod中可以有1个或者多个容器(部署程序 > 容器 > pod)
- Controller:控制器,通过它来实现对pod的管理,比如启动pod、停止pod、伸缩pod的数量等等
- Service:pod对外服务的统一入口,下面可以维护者同一类的多个pod
- Label:标签,用于对pod进行分类,同一类pod会拥有相同的标签
- NameSpace:命名空间,用来隔离pod的运行环境
集群环境搭建
2.1 环境规划
2.1.1 集群类型
kubernetes
集群大体上分为两类:一主多从
和多主多从
- 一主多从: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
- 多主多从: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
说明:为了测试简单,本次搭建的是一主两从类型的集群
2.1.2 安装方式
Kubernetes
有多种部署方式,目前主流的方式有kubeadm、minikube、二进制包Minikube
:一个用于快速搭建单节点kubernetes的工具Kubeadm
:一个用于快速搭建kubernetes集群的工具二进制包
∶从官网下载每个组件的二进制包,依次去安装,此方式对于理解kubernetes组件更加有效
说明:现在需要安装kubernetes的集群环境,但是又不想过于麻烦,所以选择使用kubeadm方式
2.1.3 主机规划
作用 | IP地址 | 操作系统 | 配置 |
---|---|---|---|
k8s-master | 192.168.93.66 | CentOS 7.5 基础设施服务器 | 2颗CPU 2G内存 |
k8s-node1 | 192.168.93.88 | CentOS 7.5 基础设施服务器 | 2颗CPU 2G内存 |
k8s-node2 | 192.168.93.89 | CentOS 7.5 基础设施服务器 | 2颗CPU 2G内存 |
2.2 环境初始化
- 检查操作系统版本
#此方式下安装kubernetes集群要求centos版本要在7.5或之上
cat /etc/redhat-release
CentOS Linux release 7.5.1804 (Core)
- 主机名解析
# 为了方便后面集群节点间的直接调用,在这配置一下主机名解析,企业中推荐使用内部DNS服务器
# 主机名成解析编辑三台服务器的/etc/hosts文件,添加下面内容
# 使用Xsell发送键到所有会话
vim /etc/hosts
192.168.93.66 k8s-master
192.168.93.88 k8s-node1
192.168.93.89 k8s-node2
- 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
# 查看是否安装
rpm -qa |grep chrony
# 安装,使用Xshell发送键到所有会话
yum install -y chrony
# 启动chrony服务并设置开机自启
systemctl start chronyd && systemctl enable chronyd
# 设置完成后查看时间是否同步
date
- 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
# 关闭防火墙并设置开机不启动
systemctl stop firewalld && systemctl disable firewalld
# 当前版本没有iptables,这一步就算完成
- 禁用
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
sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
setenforce 0
getenforce
- 禁用swap交换分区
# 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,注释掉swap分区一行
# 修改完毕之后需要重启linux服务
vim /etc/fstab
#/dev/mapper/centos-swap swap swap defaults 0 0
- 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/etc/sysctl.d/kubernetes.conf文件,添加如下配置:
vim /etc/sysctl.d/kubernetes.conf
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
br_netfilter 22256 0
- 配置ipvs功能
# 在kubernetes中service有两种代理模型,一种是基于iptables的,一种是基于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
# 安装ipset和ipvsadm
yum install ipset ipvsadm -y
#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
# 为脚本添加执行权限
chmod +x /etc/sysconfig/modules/ipvs.modules
# 执行脚本文件
/bin/bash /etc/sysconfig/modules/ipvs.modules
# 查看对应模块是否加载成功
lsmod | grep -e ip_vs -e nf_conntrack_ipv4
- 重启服务器
# 重启
reboot
# 重启后查看交换分区是否关闭成功
free -h
2.2.1 安装Docker
# 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
# 查看当前镜像源中支持的docker版本
yum list docker-ce --showduplicates
# 安装特定版本的docker-ce
# 必须指定--setopt=obsoletes=0,否则yum会自动安装更高版本,稳定
yum install --setopt=obsoletes=0 docker-ce-18.06.3.ce-3.el7 -y
# 添加一个配置文件
# Docker在默认情况下使用的Cgroup Driver为cgroupfs,而kubernetes推荐使用systemd来代替cgroupfs
mkdir /etc/docker
cat <<EOF > /etc/docker/daemon.json
"exec-opts": ["native.cgroupdriver=systemd"],
"registry-mirrors":["https://kn0t2bca.mirror.aliyuncs.com"]
EOF
# 启动并设置开机启动docker
systemctl enable docker --now
#检查docker版本和状态
docker version
2.2.2 安装kubernetes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
vim /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
# 配置kubelet的cgroup
# 编辑/etc/sysconfig/kubelet,添加下面的配器
vim /etc/sysconfig/kubelet
KUBELET_CGROUP_ARGS="--cgroup-driver=systemd"
KUBE_PROXY_MODE="ipvs"
# 设置kubelet开机自启,不用手动启动,在集群启动中会自动启动
systemctl enable kubelet
2.2.3 准备集群镜像
#在安装kubernetes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
# 下载镜像
# 定义下载镜像的列表,三台机器同时操作
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
)
# 从阿里云仓库拉取镜像
# 拉取完成之后该为k8s官方仓库的名字
# 修改完成之后再移除以阿里开头的镜像
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
#下载完成后查看下载的镜像
docker images
2.2.4 集群初始化
对集群进行初始化,并将node节点加入到集群中
下面的操作只需要在master
节点上执行即可
#创建集群
kubeadm init \\
--kubernetes-version=v1.17.4 \\ # k8s版本1.17.4
--pod-network-cidr=10.244.0.0/16 \\ # pod网络
--service-cidr=10.96.0.0/12 \\ # service网络
--apiserver-advertise-address=192.168.93.66 # 定义master节点IP地址
# 你的Kubernetes控制平面已成功初始化!
Your Kubernetes control-plane has initialized successfully!
# 根据提示创建必要文件
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
下面的操作只需要在
node
节点上执行即可
# 将node节点加入集群
# 通过在每个节点上以root身份运行以下命令,可以加入任意数量的工作节点
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 192.168.93.66:6443 --token pondho.kj8ufmze063pd2k5 \\
--discovery-token-ca-cert-hash sha256:9cdad3766150017fe9a0f432b3f5daa520454c6b6b1e1a05a8cc0bb03e41732e
# 在控制平面上运行"kubectl get nodes"以查看此节点是否加入集群
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
#在master节点查看,此时状态为NotReady,需要安装网络插件
[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master NotReady master 4m10s v1.17.4
k8s-node1 NotReady <none> 28s v1.17.4
k8s-node2 NotReady <none> 9s v1.17.4
2.2.5 安装网络插件
- kubernetes支持多种网络插件,比如flannel、calico、canal等等,任选一种使用即可,本次选择
flannel
下面操作依旧只在
master
节点执行即可,插件使用的是DaemonSet的控制器,它会在每个节点上都运行
# 获取fannel的配置文件
wget https://github.com/mrlxxx/kube-flannel.yml/archive/refs/heads/master.zip
unzip master.zip
find kube-flannel.yml-master/ -name kube-flannel.yml -exec mv . \\;
rm -rf kube-flannel.yml-master master.zip
vim kube-flannel.yml
# 修改文件中的quay.io仓库为quay-mirror.qiniu.com
# 每个节点都需要拉取镜像
docker pull lwolf/flannel:v0.12.0
# 为什么要打tag,因为kube-flannel.yaml文件里面的镜像名称就是quay.io/coreos/flannel:v0.12.0-amd64
docker tag lwolf/flannel:v0.12.0 quay-mirror.qiniu.com/coreos/flannel:v0.12.0-amd64
# 使用配置文件启动fannel网络
kubectl apply -f kube-flannel.yml
# 再次查看集群节点的状态
[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 18m v1.17.4
k8s-node1 Ready <none> 14m v1.17.4
k8s-node2 Ready <none> 14m v1.17.4
# 至此,kubernetes的集群环境搭建完成
2.3 服务部署
- 接下来在kubernetes集群中部署一个nginx程序,测试下集群是否在正常工作。
下面操作依旧只在
master
节点执行即可
# 部署nginx
[root@k8s-master ~]# kubectl create deployment nginx --image=nginx:1.14-alpine
deployment.apps/nginx created
# 暴露端口,NodePort:让集群之外的人访问
[root@k8s-master ~]# kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed
# 查看服务状态
[root@k8s-master ~]# kubectl get pods,service
NAME READY STATUS RESTARTS AGE
pod/nginx-6867cdf567-x4mvf 1/1 Running 0 75s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 22m
service/nginx NodePort 10.105.220.102 <none> 80:31730/TCP 60s
# 最后在电脑上访问部署的nginx服务
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