kubeadm installs k8s high availability cluster

Table of Contents

1. Environmental planning

2. Things to note:

3. Environment preparation:

1. Turn off firewall rules, turn off selinux, and turn off swap:

2. Modify the host name

3. Modify the hosts file on all nodes:

4. Time synchronization of all nodes:

5. All nodes implement Linux resource limits:

6. Upgrade the kernel on all nodes (optional)

7. Adjust kernel parameters:

8. Load the ip_vs module:

4. Install docker on all nodes:

1. Installation:

2. Change daemon.json configuration:

5. Install kubeadm, kubelet and kubectl:

1. Define kubernetes source:

2. Configure Kubelet to use Alibaba Cloud’s pause image:

3. Start kubelet automatically after booting:

6. Installation and configuration of high-availability components:

1. Deploy Haproxy on all master nodes:

2. Configure haproxy proxy:

3. Deploy keepalived on all master nodes:

4. Configure keepalived high availability:

5. Write a health detection script:

6. Start the high-availability proxy cluster:

7. Deploy K8S cluster:

1. Set the cluster initialization configuration file on the master01 node:

2. Update the cluster initialization configuration file:

3. All nodes pull the image:

4. Master01 node is initialized:

5. Modify the controller-manager and scheduler configuration files:

6. Deploy the network plug-in flannel:

7. All nodes join the cluster:

7.1 All master nodes join the cluster:

7.2 node node joins the cluster:

8. View cluster information:

8. Install Harbor private warehouse:

1. Install docker:

2. Modify the configuration files of all node nodes and add private warehouse configuration

3. Install Harbor:

4. Generate certificate:

5. Visit:

1. Environmental Planning

Server type	ip address
master01	192.168.30.100
master02	192.168.30.200
master03	192.168.30.203
node01	192.168.30.14
node02	192.168.30.15
hub.dhj.com	192.168.30.104

2. Notes:

The number of CPU cores on the master node must be greater than 2
The latest version is not necessarily better, but compared to the old version, the core functions are stable, but the new functions and interfaces are relatively unstable.
After learning high-availability deployment of one version, the operations of other versions are similar.
Try to upgrade the host to CentOS 7.9
The kernel is upgraded to 4.19+, a stable kernel
When deploying the k8s version, try to find a small version larger than 5 such as 1.xx.5 (this is generally a more stable version)

3. Environment preparation:

1. Close firewall rules, close selinux, and close swap:

systemctl stop firewalld
systemctl disable firewalld
setenforce 0
sed -i 's/enforcing/disabled/' /etc/selinux/config
iptables -F & amp; & amp; iptables -t nat -F & amp; & amp; iptables -t mangle -F & amp; & amp; iptables -X
swapoff -a
sed -ri 's/.*swap.*/# & amp;/' /etc/fstab

2. Modify host name

hostnamectl set-hostname master01
hostnamectl set-hostname master02
hostnamectl set-hostname master03
hostnamectl set-hostname node01
hostnamectl set-hostname node02

3. All nodes modify the hosts file:

cat >> /etc/hosts << EOF
192.168.30.100 master01
192.168.30.200 master02
192.168.30.203 master03
192.168.30.14node01
192.168.30.15node02
EOF

4. Time synchronization of all nodes:

yum -y install ntpdate
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' >/etc/timezone
ntpdate time2.aliyun.com
 
systemctl enable --now crond
 
crontab -e
*/30 * * * * /usr/sbin/ntpdate time2.aliyun.com

5. All nodes implement Linux resource limits:

vim /etc/security/limits.conf
* soft nofile 65536
*hard nofile 131072
* soft nproc 65535
*hard nproc 655350
* soft memlock unlimited
*hard memlock unlimited

6. Upgrade the kernel on all nodes (optional)

wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-devel-4.19.12-1.el7.elrepo.x86_64.rpm -O /opt/kernel-ml- devel-4.19.12-1.el7.elrepo.x86_64.rpm
wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-4.19.12-1.el7.elrepo.x86_64.rpm -O /opt/kernel-ml-4.19.12-1 .el7.elrepo.x86_64.rpm
 
cd /opt/
yum localinstall -y kernel-ml*
 
#Change kernel startup mode
grub2-set-default 0 & amp; & amp; grub2-mkconfig -o /etc/grub2.cfg
grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"
grubby --default-kernel
reboot

7. Adjust kernel parameters:

cat > /etc/sysctl.d/k8s.conf <<EOF
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 = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_timestamps = 0
net.core.somaxconn = 16384
EOF
 
#Effective parameters
sysctl --system

8. Load ip_vs module:

for i in $(ls /usr/lib/modules/$(uname -r)/kernel/net/netfilter/ipvs|grep -o "^[^.]*");do echo $i; / sbin/modinfo -F filename $i >/dev/null 2> & amp;1 & amp; & amp; /sbin/modprobe $i;done

4. Install docker on all nodes:

1. Installation:

yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum install -y docker-ce docker-ce-cli containerd.io

2. Change daemon.json configuration:

cat > /etc/docker/daemon.json <<EOF
{
  "registry-mirrors": ["https://6ijb8ubo.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "500m", "max-file": "3"
  }
}
EOF
 
#Change the resource limit of docker to systemd, keeping it consistent with k8s
 
 
systemctl daemon-reload
systemctl restart docker.service
systemctl enable docker.service

5. Install kubeadm, kubelet and kubectl:

Install kubeadm, kubelet and kubectl on all nodes

1. Define kubernetes source:

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
 
yum install -y kubelet-1.20.15 kubeadm-1.20.15 kubectl-1.20.15

2. Configure Kubelet to use Alibaba Cloud’s pause image:

cat > /etc/sysconfig/kubelet <<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=systemd --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.2"
EOF

3. Start kubelet automatically at boot:

systemctl enable --now kubelet

6. Installation and configuration of high-availability components:

1. Deploy Haproxy on all master nodes:

yum -y install haproxy

2. Configure haproxy proxy:

cat > /etc/haproxy/haproxy.cfg << EOF
global
    log 127.0.0.1 local0 info
    log 127.0.0.1 local1 warning
    chroot /var/lib/haproxy
    pidfile /var/run/haproxy.pid
    maxconn 4000
    user haproxy
    group haproxy
    daemon
    stats socket /var/lib/haproxy/stats
defaults
    mode tcp
    log global
    option tcplog
    optiondontlognull
    option redispatch
    retries 3
    timeout queue 1m
    timeout connect 10s
    timeout client 1m
    timeout server 1m
    timeout check 10s
    maxconn 3000
frontend monitor-in
    bind *:33305
    mode http
    option httplog
    monitor-uri /monitor
frontend k8s-master
    bind *:16443 #If the listening port is deployed on the same machine as the apiserver, it will conflict, change the listening port
    mode tcp
    option tcplog
    default_backend k8s-master
backend k8s-master
    mode tcp
    option tcplog
    option tcp-check
    balance roundrobin
    server k8s-master1 192.168.30.100:6443 check inter 10000 fall 2 rise 2 weight 1
    server k8s-master2 192.168.30.200:6443 check inter 10000 fall 2 rise 2 weight 1
    server k8s-master3 192.168.30.203:6443 check inter 10000 fall 2 rise 2 weight 1
EOF

3. All master nodes deploy keepalived:

yum -y install keepalived

4. Configure keepalived for high availability:

cd /etc/keepalived/
vim keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_HA1
}
 
vrrp_script chk_haproxy {
    script "/etc/keepalived/check_haproxy.sh"
    interval 2
    weight 2
}
 
vrrp_instance VI_1 {
    stateMASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    virtual_ipaddress {
        192.168.30.10 #Set VIP address
    }
    track_script {
        chk_haproxy
    }
}

5. Write health detection script:

vim check_haproxy.sh
#!/bin/bash
if ! killall -0 haproxy; then
    systemctl stop keepalived
fi
chmod + x check_haproxy.sh

6. Start the high-availability proxy cluster:

systemctl enable --now haproxy
systemctl enable --now keepalived

Seven. Deploy K8S cluster:

1. Set the cluster initialization configuration file on the master01 node:

kubeadm config print init-defaults > /opt/kubeadm-config.yaml
 
cd /opt/
vim kubeadm-config.yaml
...
11 localAPIEndpoint:
12 advertiseAddress: 192.168.30.100 #Specify the IP address of the current master node
13 bindPort: 6443
 
21 apiServer:
22 certSANs: #Add a list of certsSANs under the apiServer attribute, add the IP addresses of all master nodes and the cluster VIP address
23 - 192.168.30.10
24 - 192.168.30.100
25 - 192.168.30.200
26 - 192.168.30.203
 
30 clusterName: kubernetes
31 controlPlaneEndpoint: "192.168.30.10:16444" #Specify the cluster VIP address
32 controllerManager: {}
 
38 imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers #Specify the image download address
39 kind: ClusterConfiguration
40 kubernetesVersion: v1.20.15 #Specify kubernetes version number
41 networking:
42 dnsDomain: cluster.local
43 podSubnet: "10.244.0.0/16" #Specify the pod network segment, 10.244.0.0/16 is used to match the flannel default network segment
44 serviceSubnet: 10.96.0.0/16 #Specify service network segment
45 scheduler: {}
#Add the following content at the end
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs #Change the default kube-proxy scheduling method to ipvs mode

2. Update the cluster initialization configuration file:

kubeadm config migrate --old-config kubeadm-config.yaml --new-config new.yaml

3. All nodes pull images:

#Copy the yaml configuration file to other hosts and pull the image through the configuration file
for i in master02 master03 node01 node02; do scp /opt/new.yaml $i:/opt/; done
 
kubeadm config images pull --config /opt/new.yaml

4. Master01 node is initialized:

kubeadm init --config new.yaml --upload-certs | tee kubeadm-init.log

After initialization, the following information will appear to join the k8s cluster:

#Tips:
.........
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
    #This command is run as a regular user. Execute this command on the master01 node.
Alternatively, if you are the root user, you can run:
 
  export KUBECONFIG=/etc/kubernetes/admin.conf
    #If you are the root user, execute this command on the master01 node. Both options are acceptable. Choose your own.
 
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/
 
You can now join any number of the control-plane node running the following command on each as root:
#Master node joins the command used, record!
  kubeadm join 192.168.88.200:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:e76e4525ca29a9ccd5c24142a724bdb6ab86512420215242c4313fb830a4eb98 \
    --control-plane --certificate-key 0f2a7ff2c46ec172f834e237fcca8a02e7c29500746594c25d995b78c92dde96
 
Please note that the certificate-key gives access to cluster sensitive data, keep it secret!
As a safeguard, uploaded-certs will be deleted in two hours; If necessary, you can use
"kubeadm init phase upload-certs --upload-certs" to reload certs afterward.
 
Then you can join any number of worker nodes by running the following on each as root:
#nodeNode node is added using the command. Record!
kubeadm join 192.168.88.200:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:e76e4525ca29a9ccd5c24142a724bdb6ab86512420215242c4313fb830a4eb98

5. Modify controller-manager and scheduler configuration files:

vim /etc/kubernetes/manifests/kube-scheduler.yaml
vim /etc/kubernetes/manifests/kube-controller-manager.yaml
...
    #- --port=0 #Search for port=0 and comment out this line
 
systemctl restart kubelet
 
All master node configurations

6. Deploy network plug-in flannel:

All nodes upload the flannel image flannel.tar and network plug-in cni-plugins-linux-amd64-v0.8.6.tgz to the /opt directory, and the master node uploads the kube-flannel.yml file
cd /opt
docker load < flannel.tar
 
mv /opt/cni /opt/cni_bak
mkdir -p /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin
#Pay attention to the version you are using
 
kubectl apply -f kube-flannel.yml

7. All nodes join the cluster:

7.1 All master nodes join the cluster:

Use your own token

 kubeadm join 192.168.30.10:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:e76e4525ca29a9ccd5c24142a724bdb6ab86512420215242c4313fb830a4eb98 \
    --control-plane --certificate-key 0f2a7ff2c46ec172f834e237fcca8a02e7c29500746594c25d995b78c92dde96
 
 
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config