Kubernetes高可用集群二进制部署（六）Kubernetes集群节点添加
Kubernetes，简称 k8s（k，8 个字符，s——明白了？）或者 “kube”，是一个开源的 Linux 容器自动化运维平台，它消除了容器化应用程序在部署、伸缩时涉及到的许多手动操作。换句话说，你可以将多台主机组合成集群来运行 Linux 容器，而 Kubernetes 可以帮助你简单高效地管理那些集群。构成这些集群的主机还可以跨越公有云、私有云以及混合云。
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Kubernetes概述
使用kubeadm快速部署一个k8s集群
Kubernetes高可用集群二进制部署（一）主机准备和负载均衡器安装
Kubernetes高可用集群二进制部署（二）ETCD集群部署
Kubernetes高可用集群二进制部署（三）部署api-server
Kubernetes高可用集群二进制部署（四）部署kubectl和kube-controller-manager、kube-scheduler
Kubernetes高可用集群二进制部署（五）kubelet、kube-proxy、Calico、CoreDNS
Kubernetes高可用集群二进制部署（六）Kubernetes集群节点添加
主要介绍worker集群添加节点
1. 主机准备
1.1 主机名设置
hostnamectl set-hostname k8s-worker2
hostname
1.2 主机与IP地址解析
集群中已有节点也需要添加新节点的解析。
cat >> /etc/hosts << EOF
192.168.10.101 ha1
192.168.10.102 ha2
192.168.10.103 k8s-master1
192.168.10.104 k8s-master2
192.168.10.105 k8s-master3
192.168.10.106 k8s-worker1
192.168.10.107 k8s-worker2
EOF
1.3 主机安全设置
1.3.1 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
firewall-cmd --state
1.3.2 关闭selinux
setenforce 0
sed -ri 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
sestatus
1.4 交换分区设置
swapoff -a
sed -ri 's/.*swap.*/#&/' /etc/fstab
echo "vm.swappiness=0" >> /etc/sysctl.conf
sysctl -p
1.5 主机系统时间同步
安装软件
yum -y install ntpdate
制定时间同步计划任务
crontab -e
0 */1 * * * ntpdate time1.aliyun.com
1.6 主机系统优化
limit优化
ulimit -SHn 65535
cat <<EOF >> /etc/security/limits.conf
* soft nofile 655360
* hard nofile 131072
* soft nproc 655350
* hard nproc 655350
* soft memlock unlimited
* hard memlock unlimited
EOF
1.7 ipvs管理工具安装及模块加载
为集群节点安装，负载均衡节点不用安装
yum -y install ipvsadm ipset sysstat conntrack libseccomp
所有节点配置ipvs模块，在内核4.19+版本nf_conntrack_ipv4已经改为nf_conntrack， 4.18以下使用nf_conntrack_ipv4即可：
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack
创建 /etc/modules-load.d/ipvs.conf 并加入以下内容：
cat >/etc/modules-load.d/ipvs.conf <<EOF
ip_vs
ip_vs_lc
ip_vs_wlc
ip_vs_rr
ip_vs_wrr
ip_vs_lblc
ip_vs_lblcr
ip_vs_dh
ip_vs_sh
ip_vs_fo
ip_vs_nq
ip_vs_sed
ip_vs_ftp
ip_vs_sh
nf_conntrack
ip_tables
ip_set
xt_set
ipt_set
ipt_rpfilter
ipt_REJECT
ipip
EOF
设置为开机启动
systemctl enable --now systemd-modules-load.service
如果执行开机启动失败了，提示如下信息：
Job for systemd-modules-load.service failed because the control process exited with error code. See "systemctl status systemd-modules-load.service" and "journalctl -xe" for details.
Failed to find module 'ip_vs_fo'
具体原因是内核版本问题，不过也可以将文件中的ip_vs_fo 去掉，然后继续执行
1.8 Linux内核升级
在所有节点中安装,需要重新操作系统更换内核。
[root@localhost ~]# yum -y install perl
[root@localhost ~]# rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
[root@localhost ~]# yum -y install https://www.elrepo.org/elrepo-release-7.0-4.el7.elrepo.noarch.rpm
[root@localhost ~]# yum --enablerepo="elrepo-kernel" -y install kernel-ml.x86_64
[root@localhost ~]# grub2-set-default 0
[root@localhost ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
1.9 Linux内核优化
cat <<EOF > /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
fs.may_detach_mounts = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.netfilter.nf_conntrack_max=2310720
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 131072
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_timestamps = 0
net.core.somaxconn = 16384
EOF
sysctl --system
所有节点配置完内核后，重启服务器，保证重启后内核依旧加载
reboot -h now
重启后查看结果：
lsmod | grep --color=auto -e ip_vs -e nf_conntrack
1.10 其它工具安装(选装)
yum install wget jq psmisc vim net-tools telnet yum-utils device-mapper-persistent-data lvm2 git lrzsz -y
2. 配置免密登录
在k8s-master1节点操作
ssh-copy-id root@k8s-worker2
3. Kubernetes软件包获取
3.1 软件包获取
[root@k8s-master1 bin]# pwd
/data/k8s-work/kubernetes/server/bin
scp kubelet kube-proxy k8s-worker2:/usr/local/bin
[root@k8s-worker2 ~]# ls /usr/local/bin/kube*
/usr/local/bin/kubelet
/usr/local/bin/kube-proxy
3.2 docker-ce安装及配置
wget -O /etc/yum.repos.d/docker-ce.repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum -y install docker-ce
systemctl enable docker
systemctl start docker
cat <<EOF | sudo tee /etc/docker/daemon.json
{
"exec-opts": ["native.cgroupdriver=systemd"],
"registry-mirrors": ["https://8i185852.mirror.aliyuncs.com"]
}
EOF
必须配置native.cgroupdriver，不配置这个步骤会导致kubelet启动失败
systemctl restart docker
3.3 部署kubelet
[root@k8s-worker2 ~]# mkdir -p /etc/kubernetes
[root@k8s-worker2 ~]# mkdir -p /etc/kubernetes/ssl
[root@k8s-worker2 ~]# mkdir -p /var/lib/kubelet
[root@k8s-worker2 ~]# mkdir -p /var/log/kubernetes
[root@k8s-master1 k8s-work]# pwd
/data/k8s-work
scp kubelet-bootstrap.kubeconfig kubelet.json k8s-worker2:/etc/kubernetes/
scp ca.pem k8s-worker2:/etc/kubernetes/ssl/
scp kubelet.service k8s-worker2:/usr/lib/systemd/system/
在新加节点k8s-work2上修改kubelet.json文件
[root@k8s-worker2 ~]# vim /etc/kubernetes/kubelet.json
{
"kind": "KubeletConfiguration",
"apiVersion": "kubelet.config.k8s.io/v1beta1",
"authentication": {
"x509": {
"clientCAFile": "/etc/kubernetes/ssl/ca.pem"
},
"webhook": {
"enabled": true,
"cacheTTL": "2m0s"
},
"anonymous": {
"enabled": false
}
},
"authorization": {
"mode": "Webhook",
"webhook": {
"cacheAuthorizedTTL": "5m0s",
"cacheUnauthorizedTTL": "30s"
}
},
"address": "192.168.10.107", #当前主机的地址
"port": 10250,
"readOnlyPort": 10255,
"cgroupDriver": "systemd", #要和docker中的一致，否则启动不了
"hairpinMode": "promiscuous-bridge",
"serializeImagePulls": false,
"clusterDomain": "cluster.local.",
"clusterDNS": ["10.96.0.2"]
}
[root@k8s-worker2 ~]# systemctl daemon-reload
[root@k8s-worker2 ~]# systemctl enable --now kubelet
[root@k8s-worker2 ~]# systemctl status kubelet
# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready <none> 41h v1.21.10
k8s-master2 Ready <none> 41h v1.21.10
k8s-master3 Ready <none> 41h v1.21.10
k8s-worker1 Ready <none> 41h v1.21.10
k8s-worker2 NotReady <none> 55s v1.21.10
如果启动失败，查看日志
kubectl get pods -n kube-system -o wide
#或者
less /var/log/messages
镜像拉取错误，多试几次或者尝试将镜像下载到本地上传到服务器，用docker load -i xxxx加载镜像
3.4 部署kube-proxy
[root@k8s-master1 k8s-work]# scp kube-proxy.kubeconfig kube-proxy.yaml k8s-worker2:/etc/kubernetes/
[root@k8s-master1 k8s-work]# scp kube-proxy.service k8s-worker2:/usr/lib/systemd/system/
[root@k8s-worker2 ~]# vim /etc/kubernetes/kube-proxy.yaml
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 192.168.10.107 #当前地址
clientConnection:
kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: 10.244.0.0/16
healthzBindAddress: 192.168.10.107:10256 #当前地址
kind: KubeProxyConfiguration
metricsBindAddress: 192.168.10.107:10249 #当前地址
mode: "ipvs"
[root@k8s-worker2 ~]# mkdir -p /var/lib/kube-proxy
[root@k8s-worker2 ~]# systemctl daemon-reload
[root@k8s-worker2 ~]# systemctl enable --now kube-proxy
[root@k8s-worker2 ~]# systemctl status kube-proxy
4. 验证
[root@k8s-master1 k8s-work]# kubectl get pods -n kube-system -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
calico-kube-controllers-7cc8dd57d9-pd44j 1/1 Running 4 2d 10.244.224.4 k8s-master2 <none> <none>
calico-node-bpqfr 1/1 Running 3 2d 192.168.10.103 k8s-master1 <none> <none>
calico-node-f8c6t 1/1 Running 3 2d 192.168.10.104 k8s-master2 <none> <none>
calico-node-gndtg 1/1 Running 4 2d 192.168.10.106 k8s-worker1 <none> <none>
calico-node-pptqm 1/1 Running 3 2d 192.168.10.105 k8s-master3 <none> <none>
calico-node-sjvjc 1/1 Running 0 7m18s 192.168.10.107 k8s-worker2 <none> <none>
coredns-675db8b7cc-xlwsp 1/1 Running 2 24h 10.244.159.132 k8s-master1 <none> <none>
kubectl get nodes --show-labels
kubectl label nodes k8s-worker2 deploy.type=nginxapp
cat > nginx2.yaml << EOF
---
apiVersion: v1
kind: ReplicationController
metadata:
name: nginx-web
spec:
replicas: 1
selector:
name: nginx
template:
metadata:
labels:
name: nginx
spec:
nodeSelector:
deploy.type: nginxapp #根据标签部署
containers:
- name: nginx
image: nginx:1.19.6
ports:
- containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx-service-nodeport
spec:
ports:
- port: 80
targetPort: 80
nodePort: 30001
protocol: TCP
type: NodePort
selector:
name: nginx
EOF
kubectl apply -f nginx-work2.yaml
#查看所有名字空间的 Pod
kubectl get pods -A
#查看pod的描述信息
kubectl describe pod <podname> -n <namespace>
#删除Pod
kubectl delete pod <podname> -n <namespace>
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