Install Kubernetes on Ubuntu Jammy 22.04 using Flannel

Install Kubernetes on Ubuntu Jammy 22.04 using Flannel

Challenge during installation

Error during kubeadmin init

E0714 01:32:54.309894    2800 request.go:1092] Unexpected error when reading response body: net/http: request canceled (Client.Timeout or context cancellation while reading body)
error execution phase addon/coredns: unable to create a new DNS service: unexpected error when reading response body. Please retry. Original error: net/http: request canceled (Client.Timeout or context cancellation while reading body)
To see the stack trace of this error execute with --v=5 or higher

Steps taken to configure Kubernetes 1.27 on Ubuntu 22.04 using Flannel without any error.

Update Ubuntu packages to the latest version

sudo apt-get update

Install apt-transport-https and curl packages

sudo apt install apt-transport-https curl -y

Install containerd (reference: https://docs.docker.com/engine/install/ubuntu/)

sudo mkdir -p /etc/apt/keyrings

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt update

sudo apt install containerd.io -y

Create containerd configuration

sudo mkdir -p /etc/containerd

sudo containerd config default | sudo tee /etc/containerd/config.toml

Edit /etc/containerd/config.toml. Set SystemdCgroup = true

sudo sed -i "s/SystemdCgroup = false/SystemdCgroup = true/g" /etc/containerd/config.toml

Verify SystemCgroup change to true

grep -i SystemdCgroup /etc/containerd/config.toml

Output

            SystemdCgroup = true

Restart containerd

sudo systemctl restart containerd

Install Kubernetes

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add

sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"

sudo apt install kubeadm kubelet kubectl kubernetes-cni -y

Disable swap

sudo swapoff -a

Check and disable any swap entry if exists

sudo vim /etc/fstab

Example

# /swap.img      none    swap    sw      0       0

Avoid error “/proc/sys/net/bridge/bridge-nf-call-iptables does not exist” on kubeinit

sudo modprobe br_netfilter

sudo sysctl -w net.ipv4.ip_forward=1

Initialize Kubernetes on Master Node

sudo kubeadm init --pod-network-cidr=10.244.0.0/16

Output

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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

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 192.168.0.124:6443 --token 1wr5h3.g83f7lmcaw63nx3y \
	--discovery-token-ca-cert-hash sha256:bb713ae7c7070443de1893a03430c1222da7ff51339ecf033a7188045ac0471f

Copy to config as kubadm command

mkdir -p $HOME/.kube

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

sudo chown $(id -u):$(id -g) $HOME/.kube/config

Deploy Flannel pod network to the cluster (reference https://github.com/flannel-io/flannel)

kubectl apply -f https://raw.githubusercontent.com/flannel-io/flannel/v0.20.2/Documentation/kube-flannel.yml

All should be running now by checking all the namespaces

kubectl get all -A

Output

NAMESPACE      NAME                                   READY   STATUS    RESTARTS   AGE
kube-flannel   pod/kube-flannel-ds-9w8nb              1/1     Running   0          65s
kube-system    pod/coredns-5d78c9869d-5kkpt           1/1     Running   0          6m23s
kube-system    pod/coredns-5d78c9869d-h4lk2           1/1     Running   0          6m23s
kube-system    pod/etcd-ubuntu04                      1/1     Running   0          6m35s
kube-system    pod/kube-apiserver-ubuntu04            1/1     Running   0          6m35s
kube-system    pod/kube-controller-manager-ubuntu04   1/1     Running   0          6m35s
kube-system    pod/kube-proxy-42sqn                   1/1     Running   0          6m24s
kube-system    pod/kube-scheduler-ubuntu04            1/1     Running   0          6m35s

NAMESPACE     NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
default       service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP                  6m38s
kube-system   service/kube-dns     ClusterIP   10.96.0.10   <none>        53/UDP,53/TCP,9153/TCP   6m36s

NAMESPACE      NAME                             DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR            AGE
kube-flannel   daemonset.apps/kube-flannel-ds   1         1         1       1            1           <none>                   65s
kube-system    daemonset.apps/kube-proxy        1         1         1       1            1           kubernetes.io/os=linux   6m35s

NAMESPACE     NAME                      READY   UP-TO-DATE   AVAILABLE   AGE
kube-system   deployment.apps/coredns   2/2     2            2           6m36s

NAMESPACE     NAME                                 DESIRED   CURRENT   READY   AGE
kube-system   replicaset.apps/coredns-5d78c9869d   2         2         2       6m24s

Then you can join any number of worker nodes by running the following on each as root:

Example

kubeadm join 192.168.0.124:6443 --token 1wr5h3.g83f7lmcaw63nx3y \
	--discovery-token-ca-cert-hash sha256:bb713ae7c7070443de1893a03430c1222da7ff51339ecf033a7188045ac0471f