Install Kubernetes

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Kubespray is a pre made ansible playbook for Kubernetes installation. In this Post I will show you how to use to install a new Kubernetes cluster.

Environment

192.168.1.60    deployer.mydomain.intra (LB)
192.168.1.61    master0.mydomain.intra  (master)
192.168.1.62    master1.mydomain.intra  (master)
192.168.1.63    master2.mydomain.intra  (master)
192.168.1.64    worker0.mydomain.intra  (worker)
192.168.1.65    worker1.mydomain.intra  (worker)

# hardware requirement
4 CPU
16G RAM

Prerequirement

# deployer

nano ~/.ssh/config
Host master0
    Hostname master0.mydomain.intra
    User ansible

Host master1
    Hostname master1.mydomain.intra
    User ansible

Host master2
    Hostname master2.mydomain.intra
    User ansible

Host worker0.mydomain.intra
    Hostname worker0.mydomain.intra
    User ansible

Host worker1
    Hostname worker1.mydomain.intra
    User ansible
yum install epel-release -y
yum update -y
yum install python-pip git tmux nano -y
git clone https://github.com/kubernetes-sigs/kubespray.git
cd kubespray
pip install --user -r requirements.txt

cp -rfp inventory/sample inventory/mycluster

Configurate Installer

nano inventory/mycluster/inventory.ini
master0   ansible_host=192.168.1.61 ip=192.168.1.61
master1   ansible_host=192.168.1.62 ip=192.168.1.62
master2   ansible_host=192.168.1.63 ip=192.168.1.63
worker0   ansible_host=192.168.1.64 ip=192.168.1.64
worker1   ansible_host=192.168.1.65 ip=192.168.1.65

# ## configure a bastion host if your nodes are not directly reachable
# bastion ansible_host=x.x.x.x ansible_user=some_user

[kube-master]
master0
master1
master2

[etcd]
master0
master1
master2

[kube-node]
worker0
worker1

[calico-rr]

[k8s-cluster:children]
kube-master
kube-node
calico-rr

Run the Installer

tmux new -s kubespray
ansible-playbook -i inventory/mycluster/inventory.ini --become \
--user=centos --become-user=root cluster.yml

test install on node:
sudo -i
kubectl get node
NAME      STATUS   ROLES    AGE   VERSION
master0   Ready    master   92m   v1.15.3
master1   Ready    master   91m   v1.15.3
master2   Ready    master   91m   v1.15.3
worker0   Ready    <none>   90m   v1.15.3
worker1   Ready    <none>   90m   v1.15.3

kubectl config get-clusters 

Let’s configure an external loadbalancer

sudo firewall-cmd --add-port=6443/tcp --permanent
sudo firewall-cmd --reload

yum -y install haproxy

nano ..
listen k8s-apiserver-https
  bind *:6443
  option ssl-hello-chk
  mode tcp
  balance roundrobin
  timeout client 3h
  timeout server 3h
  server master0 192.168.1.61:6443
  server master1 192.168.1.62:6443
  server master2 192.168.1.63:6443

systemctl enable --now haproxy
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