Install Kubernetes on Arch¶

Note

This is not a step-by-step installation guide for beginners. This article assumes you have some previous experience with Linux and Kubernetes.

Install some needed utilities¶

# pacman -S conntrack-tools docker ebtables ethtool socat

Disable swap space¶

# swapoff -a
# sed -e '/swap/ s/^#*/#/' -i /etc/fstab

Load and configure the br_netfilter module¶

# modprobe br_netfilter
# sysctl net.bridge.bridge-nf-call-iptables=1
# echo "br_netfilter" > /etc/modules-load.d/br_netfilter.conf
# echo "net.bridge.bridge-nf-call-iptables=1" > /etc/sysctl.d/br_netfilter.conf

Update the ExecStart line in the docker unit file¶

/usr/lib/systemd/system/docker.service¶

ExecStart=/usr/bin/dockerd --exec-opt native.cgroupdriver=systemd --iptables=false --ip-masq=false -H fd://

Start and enable docker¶

# systemctl daemon-reload
# systemctl enable docker
# systemctl start docker

Download the latest kubernetes binaries¶

# RELEASE="$(curl -sSL https://dl.k8s.io/release/stable.txt)"
# ARCH="amd64"
# cd /usr/local/bin
# curl -L --remote-name-all https://storage.googleapis.com/kubernetes-release/release/${RELEASE}/bin/linux/${ARCH}/{kubeadm,kubelet,kubectl}
# chmod +x {kubeadm,kubelet,kubectl} && cd
# mkdir -p /etc/systemd/system/kubelet.service.d

Download the latest container network interface¶

CNI_VERSION="v0.8.6"
mkdir -p /opt/cni/bin
curl -L "https://github.com/containernetworking/plugins/releases/download/${CNI_VERSION}/cni-plugins-linux-amd64-${CNI_VERSION}.tgz" | tar -C /opt/cni/bin -xz

Download the latest container runtime interface¶

CRICTL_VERSION="v1.18.0"
mkdir -p /opt/cri
curl -L "https://github.com/kubernetes-incubator/cri-tools/releases/download/${CRICTL_VERSION}/crictl-${CRICTL_VERSION}-linux-amd64.tar.gz" | tar -C /opt/cri -xz

Create systemd unit files for kubelet¶

/etc/systemd/system/kubelet.service¶

[Unit]
Description=kubelet: The Kubernetes Node Agent
Documentation=http://kubernetes.io/docs/
Wants=network-online.target
After=network-online.target

[Service]
ExecStart=/usr/local/bin/kubelet
Restart=always
StartLimitInterval=0
RestartSec=10

[Install]
WantedBy=multi-user.target

/etc/systemd/system/kubelet.service.d/10-kubeadm.conf¶

# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf"
Environment="KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml"
# This is a file that "kubeadm init" and "kubeadm join" generates at runtime, populating the KUBELET_KUBEADM_ARGS variable dynamically
EnvironmentFile=-/var/lib/kubelet/kubeadm-flags.env
# This is a file that the user can use for overrides of the kubelet args as a last resort. Preferably, the user should use
# the .NodeRegistration.KubeletExtraArgs object in the configuration files instead. KUBELET_EXTRA_ARGS should be sourced from this file.
EnvironmentFile=-/etc/default/kubelet
ExecStart=
ExecStart=/usr/local/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS

Enable and start kubelet¶

# systemctl enable kubelet
# systemctl start kubelet

Initialize the cluster¶

Master node:

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

Worker node:

# kubeadm join 192.168.1.241:6443 --token <token> --discovery-token-ca-cert-hash sha256: <hash>

Setup kubectl config¶

$ mkdir -p $HOME/.kube
$ cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ chown $(id -u):$(id -g) $HOME/.kube/config

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/
eg:
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

Add kubectl completion for zsh¶

echo "source <(kubectl completion zsh)" >> ~/.zshrc

kubectl examples¶

Command	Description
kubectl get nodes	List all nodes in the cluster
kubectl get all -A	Show all resources from all namespaces
kubectl describe nodes	Show information of all nodes in the cluster
kubectl top node	Get node resource usage
kubectl top pod	Get pod resource usage