[TOC]

1: Hardware environment preparation

Three machines, planned for one master, two node s

2: System Software Environment Preset

1. Set up hosts

vi /etc/hosts
 Add the following
127.0.0.1 vm210

2. Close the firewall

[root@vm210 ~]# systemctl stop firewalld
[root@vm210 ~]# systemctl disable firewalld
[root@vm210 ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
[root@vm210 ~]# 

3. Install docker

Install using yum, skip if installed

yum -y install docker

4. Configure yum source

vi /etc/yum.repos.d/kubernetes.repo

//Add the following
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0

5. Set up SELinux

vi /etc/selinux/config
 Add the following SELINUX=disabled 
Comment out SELINUX=enforcing,SELINUXTYPE=targeted 

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
#SELINUX=enforcing
# SELINUXTYPE= can take one of three values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected.
#     mls - Multi Level Security protection.
#SELINUXTYPE=targeted 
SELINUX=disabled 

6. Turn off swap memory

Using swap can affect performance.kubelet disables swap

1) System level zero off

Swapoff-a, invalid after restart

2) System level shutdown

Vi/etc/fstab, comment out the swap line

A reboot is required.Not invalidated after restart

​

#
# /etc/fstab
# Created by anaconda on Mon Dec  2 21:02:22 2019
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root /                       xfs     defaults        0 0
UUID=b232659c-bd84-46f0-928b-a46d55500934 /boot                   xfs     defaults        0 0
#/dev/mapper/centos-swap swap  

7. Set up iptables

Solve the problem of iptables causing traffic to be routed incorrectly

cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

Three: Master node installs kubeadm

1. Install kubelet and kubeadm and kubectl

yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
systemctl enable --now kubelet

2. Start docker

systemctl enable docker && systemctl start docker

3. Download the required mirror

for i in `kubeadm config images list`; do 
  imageName=${i#k8s.gcr.io/}
  docker pull registry.aliyuncs.com/google_containers/$imageName
  docker tag registry.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
  docker rmi registry.aliyuncs.com/google_containers/$imageName
done;

4. Changing the parameters of kubelet

vi /etc/sysconfig/kubelet

Change to the following parameters
KUBELET_EXTRA_ARGS=--cgroup-driver=systemd

5.kubeadm initialization

kubeadm init

//When completed, the following results are available
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

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 192.168.159.210:6443 --token ct4248.2egr8dv9k4avqul7 \
    --discovery-token-ca-cert-hash sha256:4ca4f6835e9cd70b43be16b81d8340876dca0e064c6168342c140140d17f449b 
    
    //The last command needs to be executed in the node to join the k8s cluster

Follow the prompt to execute the following command
  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Four: node node installs kubeadm

1. Install kubeadm kubelet

yum -y install kubeadm kubelet

2. Start docker

systemctl enable docker && systemctl start docker

3. Download the required mirror

for i in `kubeadm config images list`; do 
  imageName=${i#k8s.gcr.io/}
  docker pull registry.aliyuncs.com/google_containers/$imageName
  docker tag registry.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
  docker rmi registry.aliyuncs.com/google_containers/$imageName
done;

4. Changing the parameters of kubelet

vi /etc/sysconfig/kubelet

Change to the following parameters
KUBELET_EXTRA_ARGS=--cgroup-driver=systed

5) Join master

token Come from master Node Execution kubeinit Results
kubeadm join 192.168.159.210:6443 --token ct4248.2egr8dv9k4avqul7 \
    --discovery-token-ca-cert-hash sha256:4ca4f6835e9cd70b43be16b81d8340876dca0e064c6168342c140140d17f449b 

Five: Install network plug-ins

kubectl apply -f https://docs.projectcalico.org/v3.8/manifests/calico.yaml

Six: Query k8s cluster status

1. Query node

[root@vm210 k8s]# kubectl get nodes
NAME    STATUS   ROLES    AGE     VERSION
vm210   Ready    master   58m     v1.16.3
vm211   Ready    <none>   21m     v1.16.3
vm212   Ready    <none>   6m29s   v1.16.3

2. Query pods status

root@vm210 k8s]# kubectl  get pods --namespace=kube-system
NAME                                      READY   STATUS            RESTARTS   AGE
calico-kube-controllers-55754f75c-7wvrb   1/1     Running           0          6m20s
calico-node-9x82m                         1/1     Running           0          6m20s
calico-node-gn5qh                         1/1     Running           0          6m20s
calico-node-h8kvz                         0/1     PodInitializing   0          6m20s
coredns-5644d7b6d9-h9sn2                  1/1     Running           0          59m
coredns-5644d7b6d9-pwfl5                  1/1     Running           0          59m
etcd-vm210                                1/1     Running           0          58m
kube-apiserver-vm210                      1/1     Running           0          58m
kube-controller-manager-vm210             1/1     Running           0          58m
kube-proxy-6hjk2                          1/1     Running           0          22m
kube-proxy-bcmhh                          1/1     Running           0          7m31s
kube-proxy-bt9rn                          1/1     Running           0          59m
kube-scheduler-vm210                      1/1     Running           0          58m

3. Query the specific state of the pod

kubectl --namespace=kube-system describe pod <pod_name>

kubectl --namespace=kube-system describe pod calico-node-h8kvz

4. The master node can also schedule pod s like the node node node

kubectl taint nodes --all node-role.kubernetes.io/master-


[root@vm210 k8s]# kubectl taint nodes --all node-role.kubernetes.io/master-
node/vm210 untainted
taint "node-role.kubernetes.io/master" not found
taint "node-role.kubernetes.io/master" not found

5. Query k8s version

[root@vm210 k8s]# kubectl version
Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.3", GitCommit:"b3cbbae08ec52a7fc73d334838e18d17e8512749", GitTreeState:"clean", BuildDate:"2019-11-13T11:23:11Z", GoVersion:"go1.12.12", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.3", GitCommit:"b3cbbae08ec52a7fc73d334838e18d17e8512749", GitTreeState:"clean", BuildDate:"2019-11-13T11:13:49Z", GoVersion:"go1.12.12", Compiler:"gc", Platform:"linux/amd64"}

So far, the Kubernetes cluster has been rapidly set up using the kubeadm tool.If the installation fails, you can execute the kubeadm reset command to restore the host, re-execute the kubeadm init, or the kubeadm join command to install again.

If you have any questions during the installation, you are welcome to add vx:xydjun.Discuss and communicate with each other