CentOS Linux Release 7.6.1810 64bit
Docker version 18.06.1-ce Git commit: e68fc7a
Kubernetes version: v1.14.3
Hostname IP Role
SRV-K8S-MASTER01 172.16.5.211 k8s master node
SRV-K8S-WORKER01 172.16.5.213 k8s slave node
SRV-K8S-WORKER02 172.16.5.214 k8s slave node
Setup network on CentOS 7
Update source
yum clean all
yum makecache
yum update
Install utils
yum install epel-release -y
yum install htop nano wget nfs-utils -y
Set Up Time Synchronization
yum install ntp ntpdate
systemctl enable ntpd
timedatectl set-timezone Europe/Paris
Close firewall on all nodes
systemctl stop firewalld
systemctl disable firewalld
Disable SELINUX on all nodes
setenforce 0
vi /etc/selinux/config
SELINUX=disabled
Disable swap on all nodes
swapoff -a
Comment swap autoload config in the /etc/fstab file and varify with free -m.
Add following content on each /etc/hosts file
172.16.5.211 SRV-K8S-MASTER01
172.16.5.213 SRV-K8S-WORKER01
172.16.5.214 SRV-K8S-WORKER02
Create /etc/sysctl.d/k8s.conf file
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
vm.swappiness = 0
Take change effect
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf
Install recommended ipvs management tools
yum -y install ipset ipvsadm
Open kernel ipvs modules for kube-proxy
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
Install and lanuch Docker on each nodes
yum install docker-ce docker-ce-cli containerd.io
systemctl start docker
systemctl stop docker
systemctl enable docker
Set docker configuration to use overlay2 Docker storage driver
cat <<EOF > /etc/docker/daemon.json
{
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2",
"storage-opts": [
"overlay2.override_kernel_check=true"
]
}
EOF
Start docker
systemctl start docker
Install kubelet, kubectl and kubeadm on each node
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
Installation
yum makecache fast
yum install -y kubelet kubeadm kubectl
Init Kubernetes cluster on master node
# auto start on boot
systemctl enable kubelet && systemctl start kubelet
kubeadm init --config /opt/k8s/kubeadm-init.conf
Detailed cluster initialization process
[root@SRV-K8S-MASTER01 k8s]# kubeadm init --config kubeadm-init.conf
[init] Using Kubernetes version: v1.14.3
[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'
[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] Activating the kubelet service
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[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/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [srv-k8s-master01.netboot.lan localhost] and IPs [172.16.5.211 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [srv-k8s-master01.netboot.lan localhost] and IPs [172.16.5.211 127.0.0.1 ::1]
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [srv-k8s-master01.netboot.lan kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10 .96.0.1 172.16.5.211]
[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
[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"
[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 15.502251 seconds
[upload-config] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.14" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --experimental-upload-certs
[mark-control-plane] Marking the node srv-k8s-master01.netboot.lan as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node srv-k8s-master01.netboot.lan as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: dx42vx.5u8emct7bvz6l2kv
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[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
[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
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 172.16.5.211:6443 --token dx42vx.5u8emct7bvz6l2kv --discovery-token-ca-cert-hash sha256:de880889c87fcc683be095bac569bafaaeb80bbdff89307f0afb9398d5199983
Config kubectl on the master node
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
Download pod networks config file kube-flannel.yml and create pod networks by follwing command
kubectl apply -f kubectl apply -f /opt/k8s/kube-system/weave-net*.yaml
If execute success, checked CoreDNS Pod running status
kubectl get pod --all-namespaces -owide --watch
Check Kubernetes master status to check ready
kubectl get nodes
NAME STATUS ROLES AGE VERSION
srv-k8s-master01 Ready master 21m v1.14.3
Add slave nodes, run following command on each slave node
kubeadm join 172.16.5.211:6443 --token dx42vx.5u8emct7bvz6l2kv --discovery-token-ca-cert-hash sha256:de880889c87fcc683be095bac569bafaaeb80bbdff89307f0afb9398d5199983
If you forget token, run following command on master node
kubeadm token list
Run following commands on the master node
kubectl get nodes
NAME STATUS ROLES AGE VERSION
srv-k8s-master01 Ready master 13m v1.14.3
srv-k8s-worker01 Ready <none> 107s v1.14.3
srv-k8s-worker02 Ready <none> 91s v1.14.3