Step-by-Step Guide to Install CentOS, Docker, and Build a Kubernetes Cluster

Install required CentOS packages

Install net-tools and disable the firewalld service.

# yum install -y net-tools

# systemctl stop firewalld && systemctl disable firewalld
# setenforce 0
# sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config

Install Docker CE

Set up the Docker CE repository and install Docker.

# yum install -y yum-utils device-mapper-persistent-data lvm2

# yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

# yum-config-manager --disable docker-ce-edge

# yum makecache fast

# yum -y install docker-ce

Start Docker and run the hello‑world container to verify the installation.

# systemctl start docker
# docker run hello-world

Install kubelet, kubeadm and kubectl packages

Configure the Kubernetes yum repository (Aliyun mirror) and install the required packages.

# 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
EOF

# yum install -y kubectl kubelet kubeadm kubernetes-cni

Modify cgroup driver and cAdvisor port

Change the kubelet cgroup driver to cgroupfs and set the cAdvisor port to 4194.

# vi /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
# add/modify: KUBELET_CGROUP_ARGS=--cgroup-driver=cgroupfs
# Environment="KUBELET_CADVISOR_ARGS=--cadvisor-port=4194"

Enable and start kubelet service

# systemctl enable kubelet && systemctl start kubelet

Initialize the master node

Reset any previous state and run kubeadm init with the desired API server address, Kubernetes version and pod network CIDR.

# kubeadm reset && kubeadm init \
    --apiserver-advertise-address=192.168.0.100 \
    --kubernetes-version=v1.7.5 \
    --pod-network-cidr=10.200.0.0/16

After the control plane is ready, copy the admin kubeconfig for the regular user.

# mkdir -p $HOME/.kube
# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
# chown $(id -u):$(id -g) $HOME/.kube/config

Add worker nodes

On each node run the join command generated by the master.

# kubeadm join --token 0696ed.7cd261f787453bd9 192.168.0.100:6443

Install Flannel networking on the master

# docker pull quay.io/coreos/flannel:v0.8.0-amd64
# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.8.0/Documentation/kube-flannel.yml
# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.8.0/Documentation/kube-flannel-rbac.yml

Verify the cluster

# kubectl get cs
# kubectl get nodes
# kubectl get pods --all-namespaces

Troubleshooting

If you encounter “The connection to the server localhost:8080 was refused”, set the kubeconfig environment variable:

# export KUBECONFIG=/etc/kubernetes/admin.conf
# source ~/.bash_profile