Details: https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
Pre-requisite
A compatible Linux host.
Verify the MAC address and product_uuid are unique for every node. Kubernetes uses these values to uniquely identify the nodes in the cluster.
ip link
sudo cat /sys/class/dmi/id/product_uuid
Check network adapters
Check required ports
These required ports need to be open in order for Kubernetes components to communicate with each other. The pod network plugin you use may also require certain ports to be open. Since this differs with each pod network plugin
nc 127.0.0.1 6443 -v
2 GB or more of RAM per machine (any less will leave little room for your apps).
2 CPUs or more.
Swap configuration. The default behavior of a kubelet was to fail to start if swap memory was detected on a node. See Swap memory management for more details.
- You MUST disable swap if the kubelet is not properly configured to use swap. For example,
sudo swapoff -a will disable swapping temporarily. To make this change persistent across reboots, make sure swap is disabled in config files like /etc/fstab, systemd.swap, depending how it was configured on your system.
sudo swapoff -a
Network Configuration
Enable IPv4 packet forwarding:
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
EOF
sudo sysctl --system
sysctl net.ipv4.ip_forward
NOTE: Starting with v1.22 and later, when creating a cluster with kubeadm, if the user does not set the cgroupDriver field under KubeletConfiguration, kubeadm defaults it to systemd.
curl -LO https://github.com/containerd/containerd/releases/download/v1.7.18/containerd-1.7.18-linux-amd64.tar.gz
sudo tar Cxzvf /usr/local containerd-1.7.18-linux-amd64.tar.gz
curl -O https://raw.githubusercontent.com/containerd/containerd/main/containerd.service
sudo mv containerd.service /lib/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now containerd
Runc
curl -LO https://github.com/opencontainers/runc/releases/download/v1.1.12/runc.amd64
sudo install -m 755 runc.amd64 /usr/local/sbin/runc
Install CNI plugins
~> curl -LO https://github.com/containernetworking/plugins/releases/download/v1.5.0/cni-plugins-linux-amd64-v1.5.0.tgz
~> mkdir -p /opt/cni/bin
~> sudo tar Cxzvf /opt/cni/bin cni-plugins-linux-amd64-v1.5.0.tgz
~> ls /opt/cni/bin/
LICENSE bandwidth dhcp firewall host-local loopback portmap sbr tap vlan
README.md bridge dummy host-device ipvlan macvlan ptp static tuning vrf
sudo mkdir -p /etc/containerd/
containerd config default | sudo tee /etc/containerd/config.toml
sudo vim /etc/containerd/config.toml
sudo systemctl restart containerd
kubeadm will not install or manage kubelet or kubectl for you, so you will need to ensure they match the version of the Kubernetes control plane you want kubeadm to install for you.
ip route show
Optional: Preparing the required container images
This step is optional and only applies in case you wish kubeadm init and kubeadm join to not download the default container images which are hosted at registry.k8s.io.
Initializing your control-plane node
(Recommended) If you have plans to upgrade this single control-plane kubeadm cluster to high availability you should specify the --control-plane-endpoint to set the shared endpoint for all control-plane nodes. Such an endpoint can be either a DNS name or an IP address of a load-balancer.
Choose a Pod network add-on, and verify whether it requires any arguments to be passed to kubeadm init. Depending on which third-party provider you choose, you might need to set the --pod-network-cidr to a provider-specific value. See Installing a Pod network add-on.
(Optional) kubeadm tries to detect the container runtime by using a list of well known endpoints. To use different container runtime or if there are more than one installed on the provisioned node, specify the --cri-socket argument to kubeadm. See Installing a runtime.
Run init
~> sudo kubeadm init --pod-network-cidr 10.33.0.0/16
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 10.0.8.15:6443 --token vajf1q.ahw188f33xklo8um \
--discovery-token-ca-cert-hash sha256:58e837184a19c648286f21ccac308b2894fc0592ceee7c24f1ce0e616885bc52
kubect get nodes
kubect get pods -n kube-system
Deploy CNI Plugins
kubectl taint nodes vagrant node-role.kubernetes.io/control-plane-
curl https://raw.githubusercontent.com/projectcalico/calico/v3.28.0/manifests/calico.yaml -O
kubectl apply -f calico.yaml
Untaint Nodes
kubectl taint nodes vagrant node.cilium.io/agent-not-ready-
