一、集群規(guī)劃及架構(gòu)
官方文檔：
二進(jìn)制下載地址
環(huán)境規(guī)劃：
- pod網(wǎng)段：10.244.0.0/16
- service網(wǎng)段：10.10.0.0/16
- 注意： pod和service網(wǎng)段不可沖突，如果沖突會導(dǎo)致K8S集群安裝失敗。
| 主機(jī)名 | IP地址 | 操作系統(tǒng) |
|---|---|---|
| master-1 | 16.32.15.200 | CentOS7.8 |
| node-1 | 16.32.15.201 | CentOS7.8 |
| node-2 | 16.32.15.202 | CentOS7.8 |
二、系統(tǒng)初始化準(zhǔn)備(所有節(jié)點(diǎn)同步操作)
1、關(guān)閉防火墻
systemctl disable firewalld --now
setenforce 0
sed -i -r 's/SELINUX=[ep].*/SELINUX=disabled/g' /etc/selinux/config
2、配置域名解析
cat >> /etc/hosts << EOF
16.32.15.200 master-1
16.32.15.201 node-1
16.32.15.202 node-2
EOF
在指定主機(jī)上面修改主機(jī)名
hostnamectl set-hostname master-1 && bash
hostnamectl set-hostname node-1 && bash
hostnamectl set-hostname node-2 && bash
3、配置服務(wù)器時間保持一致
yum -y install ntpdate
ntpdate ntp1.aliyun.com
添加定時同步 每天凌晨1點(diǎn)自動同步時間
echo "0 1 * * * ntpdate ntp1.aliyun.com" >> /var/spool/cron/root
crontab -l
4、禁用swap交換分區(qū)（kubernetes強(qiáng)制要求禁用）
swapoff --all
禁止開機(jī)自啟動swap交換分區(qū)
sed -i -r '/swap/ s/^/#/' /etc/fstab
5、修改Linux內(nèi)核參數(shù)，添加網(wǎng)橋過濾器和地址轉(zhuǎn)發(fā)功能
cat >> /etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
sysctl -p /etc/sysctl.d/kubernetes.conf
加載網(wǎng)橋過濾器模塊
modprobe br_netfilter
lsmod | grep br_netfilter # 驗證是否生效
6、配置ipvs功能
在kubernetes中Service有兩種代理模型，一種是基于iptables的，一種是基于ipvs，兩者對比ipvs的性能要高，如果想要使用ipvs模型，需要手動載入ipvs模塊
yum -y install ipset ipvsadm
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
chmod +x /etc/sysconfig/modules/ipvs.modules
# 執(zhí)行腳本
/etc/sysconfig/modules/ipvs.modules
# 驗證ipvs模塊
lsmod | grep -e ip_vs -e nf_conntrack_ipv4
7、安裝Docker容器組件
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
yum makecache
# yum-utils軟件用于提供yum-config-manager程序
yum install -y yum-utils
# 使用yum-config-manager創(chuàng)建docker阿里存儲庫
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum install docker-ce-20.10.6 docker-ce-cli-20.10.6 -y
Docker配置加速源：
mkdir /etc/docker
cat <<EOF > /etc/docker/daemon.json
{
"registry-mirrors": ["https://aoewjvel.mirror.aliyuncs.com"],
"exec-opts": ["native.cgroupdriver=systemd"]
}
EOF
# 啟動docker并設(shè)置開機(jī)自啟
systemctl enable docker --now
systemctl status docker
8、重啟服務(wù)器 可略過
reboot
三、安裝并配置cri-dockerd插件
官網(wǎng)下載地址
三臺服務(wù)器同時操作
1、安裝cri-dockerd插件
wget https://github.com/Mirantis/cri-dockerd/releases/download/v0.3.1/cri-dockerd-0.3.1-3.el7.x86_64.rpm
rpm -ivh cri-dockerd-0.3.1-3.el7.x86_64.rpm
2、備份并更新cri-docker.service文件
mv /usr/lib/systemd/system/cri-docker.service{,.default}
vim /usr/lib/systemd/system/cri-docker.service
[Unit]
Description=CRI Interface for Docker Application Container Engine
Documentation=https://docs.mirantis.com
After=network-online.target firewalld.service docker.service
Wants=network-online.target
Requires=cri-docker.socket
[Service]
Type=notify
ExecStart=/usr/bin/cri-dockerd --network-plugin=cni --pod-infra-container-image=registry.aliyuncs.com/google_containers/pause:3.7
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
StartLimitBurst=3
StartLimitInterval=60s
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
Delegate=yes
KillMode=process
[Install]
WantedBy=multi-user.target
3、啟動cir-dockerd
systemctl daemon-reload
systemctl start cri-docker.service
systemctl enable cri-docker.service
四、安裝kubeadm(所有節(jié)點(diǎn)同步操作)
1、配置國內(nèi)yum源，一鍵安裝 kubeadm、kubelet、kubectl
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0
EOF
yum install -y kubelet-1.27.0 kubeadm-1.27.0 kubectl-1.27.0
2、kubeadm將使用kubelet服務(wù)以容器方式部署kubernetes的主要服務(wù)，所以需要先啟動kubelet服務(wù)
systemctl enable kubelet.service --now
五、初始化集群
在master-1主機(jī)上進(jìn)行操作
1、生成初始化默認(rèn)配置文件
kubeadm config print init-defaults > kubeadm.yaml
我們根據(jù)自己需求進(jìn)行修改默認(rèn)配置文件，我主要更改了一下配置如下：
- advertiseAddress：更改為master的IP地址
- criSocket：指定容器運(yùn)行時
- imageRepository：配置國內(nèi)加速源地址
- podSubnet：pod網(wǎng)段地址
- serviceSubnet：services網(wǎng)段地址
- 末尾添加了指定使用ipvs，開啟systemd
- nodeRegistration.name：改為當(dāng)前主機(jī)名稱
最終初始化配置文件如下：
apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
- system:bootstrappers:kubeadm:default-node-token
token: abcdef.0123456789abcdef
ttl: 24h0m0s
usages:
- signing
- authentication
kind: InitConfiguration
localAPIEndpoint:
advertiseAddress: 16.32.15.200
bindPort: 6443
nodeRegistration:
criSocket: unix:///var/run/cri-dockerd.sock
imagePullPolicy: IfNotPresent
name: master-1
taints: null
---
apiServer:
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: 1.27.0
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16
serviceSubnet: 10.96.0.0/12
scheduler: {}
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
cgroupDriver: systemd
2、進(jìn)行初始化
kubeadm init --config=kubeadm.yaml --ignore-preflight-errors=SystemVerification
初始化成功后輸出如下內(nèi)容：
[init] Using Kubernetes version: v1.27.0
[preflight] Running pre-flight checks
[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'
W0504 22:24:16.508649 4725 images.go:80] could not find officially supported version of etcd for Kubernetes v1.27.0, falling back to the nearest etcd version (3.5.7-0)
[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-1] and IPs [10.96.0.1 16.32.15.200]
[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-1] and IPs [16.32.15.200 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [localhost master-1] and IPs [16.32.15.200 127.0.0.1 ::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"
W0504 22:24:34.897353 4725 images.go:80] could not find officially supported version of etcd for Kubernetes v1.27.0, falling back to the nearest etcd version (3.5.7-0)
[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 10.002479 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config" 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-1 as control-plane by adding the labels: [node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
[mark-control-plane] Marking the node master-1 as control-plane by adding the taints [node-role.kubernetes.io/control-plane:NoSchedule]
[bootstrap-token] Using token: abcdef.0123456789abcdef
[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 $(id -u):$(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:
kubeadm join 16.32.15.200:6443 --token abcdef.0123456789abcdef \
--discovery-token-ca-cert-hash sha256:afef55c724c1713edb7926d98f8c4063fbae928fc4eb11282589d6485029b9a6
3、配置kubectl的配置文件config，相當(dāng)于對kubectl進(jìn)行授權(quán)，這樣kubectl命令可以使用這個證書對k8s集群進(jìn)行管理
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
驗證使用可以使用 kubectl 命令
kubectl get nodes
六、Node節(jié)點(diǎn)添加到集群
在兩臺node節(jié)點(diǎn)進(jìn)行操
1、使用以下命令創(chuàng)建并查看token
kubeadm token create --print-join-command
2、在兩臺node節(jié)點(diǎn)執(zhí)行，注意添加--cri-socket=指定cri-dockerd.sock。
kubeadm join 16.32.15.200:6443 --token abcdef.0123456789abcdef --discovery-token-ca-cert-hash sha256:d3d7853ba7691fad218fdfa1027390c7c68e8cf0d3c5033e37170ce00d09901c --cri-socket=unix:///var/run/cri-dockerd.sock
成功加入到集群如下圖：
3、給兩臺node節(jié)點(diǎn)打上標(biāo)簽
master-1主機(jī)上執(zhí)行
kubectl label nodes node-1 node-role.kubernetes.io/work=work
kubectl label nodes node-2 node-role.kubernetes.io/work=work
4、查看集群節(jié)點(diǎn)
kubectl get nodes
七、安裝網(wǎng)絡(luò)組件Calico
Calico在線文檔地址：
Calico.yaml下載地址：
1、上傳calico.yaml文件到服務(wù)器中，下面提供calico.yaml文件內(nèi)容：
在master主機(jī)執(zhí)行
kubectl apply -f calico.yaml
2、查看集群狀態(tài) && 查看自帶Pod狀態(tài)
kubectl get nodes
3、查看組件狀態(tài) 是否為 Running狀態(tài) 如下圖：
kubectl get pods -n kube-system -o wide
八、測試CoreDNS解析可用性
1、下載busybox:1.28鏡像文章來源：http://www.zghlxwxcb.cn/news/detail-443405.html
docker pull busybox:1.28
2、測試coredns文章來源地址http://www.zghlxwxcb.cn/news/detail-443405.html
kubectl run busybox --image busybox:1.28 --restart=Never --rm -it busybox -- sh
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes.default.svc.cluster.local
Server: 10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
Name: kubernetes.default.svc.cluster.local
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
- 注意：busybox要用指定的1.28版本，不能用最新版本，最新版本，nslookup會解析不到dns和ip
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