Simple Kubernetes install

Those that are interested in Trident and just getting started with Kubernetes frequently ask us for a simple way to install Kubernetes to try it out.

These instructions provide a bare-bones single node cluster that Trident will be able to integrate with for demonstration purposes.

Warning

The Kubernetes cluster these instructions build should never be used in production. Follow production deployment guides provided by your distribution for that.

This is a simplification of the kubeadm install guide provided by Kubernetes. If you’re having trouble, your best bet is to revert to that guide.

Prerequisites

An Ubuntu 16.04 machine with at least 1 GB of RAM.

These instructions are very opinionated by design, and will not work with anything else. For more generic instructions, you will need to run through the entire kubeadm install guide.

Install Docker CE 17.03

apt-get update && apt-get install -y curl apt-transport-https

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/docker.list
deb https://download.docker.com/linux/$(lsb_release -si | tr '[:upper:]' '[:lower:]') $(lsb_release -cs) stable
EOF
apt-get update && apt-get install -y docker-ce=$(apt-cache madison docker-ce | grep 17.03 | head -1 | awk '{print $3}')

Install the appropriate version of kubeadm, kubectl and kubelet

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y kubeadm=1.12\* kubectl=1.12\* kubelet=1.12\* kubernetes-cni=0.6\*

Configure the host

swapoff -a
# Comment out swap line in fstab so that it remains disabled after reboot
vi /etc/fstab

Create the cluster

kubeadm init --kubernetes-version stable-1.12 --token-ttl 0 --pod-network-cidr=192.168.0.0/16

Install the kubectl creds and untaint the cluster

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl taint nodes --all node-role.kubernetes.io/master-

Add an overlay network

kubectl apply -f https://docs.projectcalico.org/v2.6/getting-started/kubernetes/installation/hosted/kubeadm/1.6/calico.yaml

Verify that all of the services started

After completing those steps, you should see output similar to this within a few minutes:

# kubectl get po -n kube-system
NAME                                       READY     STATUS    RESTARTS   AGE
calico-etcd-rvgzs                          1/1       Running   0          9d
calico-kube-controllers-6ff88bf6d4-db64s   1/1       Running   0          9d
calico-node-xpg2l                          2/2       Running   0          9d
etcd-scspa0333127001                       1/1       Running   0          9d
kube-apiserver-scspa0333127001             1/1       Running   0          9d
kube-controller-manager-scspa0333127001    1/1       Running   0          9d
kube-dns-545bc4bfd4-qgkrn                  3/3       Running   0          9d
kube-proxy-zvjcf                           1/1       Running   0          9d
kube-scheduler-scspa0333127001             1/1       Running   0          9d

Notice that all of the Kubernetes services are in a Running state. Congratulations! At this point your cluster is operational.

If this is the first time you’re using Kubernetes, we highly recommend a walkthrough to familiarize yourself with the concepts and tools.