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Kubernetes Node Addition / Using kubeadm / Ubuntu 18.04 Environment

Kubernetes Node Addition / Using kubeadm / Ubuntu 18.04 Environment

1. Installation Environment

The installation environment is as follows.

  • HyperV
    • Master Node : Ubuntu Desktop 18.04.1 64bit : 1 node
    • Worker Node : Ubuntu Server 18.04.1 64bit : 2 nodes
  • Docker : 19.03.1
  • Kubernetes 1.15.3
    • Network Plugin : using calico or flannel or cilium
    • Dashboard Addon : using Dashboard
  • kubeadm 1.15.3
    • When building a Cluster environment using VMs, Kubernetes can be easily installed using kubeadm.
  • Password
    • For convenient installation, all Passwords required for Kubernetes installation are unified to root.
  • Installation is performed as root User on all Nodes.

2. Package Installation 

(Added Node)$ apt-get update && apt-get install apt-transport-https ca-certificates curl gnupg-agent software-properties-common
(Added Node)$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
(Added Node)$ add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb-release -cs) stable"
(Added Node)$ apt-get update && sudo apt-get install docker-ce=5:19.03.1~3-0~ubuntu-bionic docker-ce-cli containerd.io

Install Docker on the Node to be added.

(Added Node)$ apt-get update && apt-get install -y apt-transport-https curl
(Added Node)$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
(Added Node)$ echo deb http://apt.kubernetes.io/ kubernetes-xenial main > /etc/apt/sources.list.d/kubernetes.list
(Added Node)$ apt-get update && apt-get install -y kubeadm=1.15.3-00 kubelet=1.15.3-00

Install kubeadm and kubelet on the Node to be added.

3. Node Addition

3.1. Master Node 

(Master Node)$ kubeadm token create
4n1agp.j97evoelu2k35dre
(Master Node)$ kubeadm token list
TOKEN                     TTL       EXPIRES                USAGES                   DESCRIPTION   EXTRA GROUPS
4n1agp.j97evoelu2k35dre   23h       2020-07-27T08:03:59Z   authentication,signing   <none>        system:bootstrappers:kubeadm:default-node-token

Create a Token using kubeadm.

(Master Node)$ openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
060896fc4bfe949304b8c1af7b23bb5c4e60e6d242722ce5bd02fe4cbc94aabe

Obtain the Hash value of the CA certificate.

3.2. Added Worker Node 

(Added Node)$ kubeadm join 30.0.0.34:6443 --token 4n1agp.j97evoelu2k35dre --discovery-token-ca-cert-hash sha256:060896fc4bfe949304b8c1af7b23bb5c4e60e6d242722ce5bd02fe4cbc94aabe

Join the Cluster using the Token created with kubeadm and the Hash value of the CA certificate. 30.0.0.34 is the IP of the Master Node.

4. Node Addition Verification 

(Master Node)$ kubectl get nodes
NAME   STATUS   ROLES    AGE    VERSION
vm01   Ready    master   236d   v1.15.3
vm02   Ready    <none>   236d   v1.15.3
vm03   Ready    <none>   236d   v1.15.3
vm04   Ready    <none>   101s   v1.15.3

Verify the added Node from the Master Node. Node04 is the added Node.

5. References

Kubernetes netshoot Shell Pod ExecutionKubernetes OpenStack External Cloud Provider Compile / Ubuntu 18.04 Environment