website/docs/setup/independent/install-kubeadm.md

3.4 KiB

title
Installing kubeadm

{% capture overview %}

This page shows how to use install kubeadm.

{% endcapture %}

{% capture prerequisites %}

  • One or more machines running Ubuntu 16.04+, CentOS 7 or HypriotOS v1.0.1+
  • 1GB or more of RAM per machine (any less will leave little room for your apps)
  • Full network connectivity between all machines in the cluster (public or private network is fine)

{% endcapture %}

{% capture steps %}

Installing Docker

On each of your machines, install Docker. Version 1.12 is recommended, but v1.10 and v1.11 are known to work as well. Versions 1.13 and 17.03+ have not yet been tested and verified by the Kubernetes node team. For installation instructions, see Install Docker.

Installing kubectl

On each of your machines, install kubectl. You only need kubectl on the master, but it can be useful to have on the other nodes as well.

Installing kubelet and kubeadm

You will install these packages on all of your machines:

  • kubelet: the most core component of Kubernetes. It runs on all of the machines in your cluster and does things like starting pods and containers.

  • kubeadm: the command to bootstrap the cluster.

Note: If you already have kubeadm installed, you should do a apt-get update && apt-get upgrade or yum update to get the latest version of kubeadm. See the kubeadm release notes if you want to read about the different kubeadm releases

For each machine:

  • SSH into the machine and become root if you are not already (for example, run sudo su -).

  • If the machine is running Ubuntu or HypriotOS, run:

    apt-get update && apt-get install -y apt-transport-https
    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
    # Install docker if you don't have it already.
    apt-get install -y docker-engine
    apt-get install -y kubelet kubeadm kubernetes-cni
    
  • If the machine is running CentOS, run:

    cat <<EOF > /etc/yum.repos.d/kubernetes.repo
    [kubernetes]
    name=Kubernetes
    baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
    enabled=1
    gpgcheck=1
    repo_gpgcheck=1
    gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
            https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
    EOF
    setenforce 0
    yum install -y docker kubelet kubeadm kubernetes-cni
    systemctl enable docker && systemctl start docker
    systemctl enable kubelet && systemctl start kubelet
    

    The kubelet is now restarting every few seconds, as it waits in a crashloop for kubeadm to tell it what to do.

    Note: Disabling SELinux by running setenforce 0 is required to allow containers to access the host filesystem, which is required by pod networks for example. You have to do this until SELinux support is improved in the kubelet.

While this guide is correct for kubeadm 1.6, the previous version is still available but can be a bit tricky to install. See below for details.

{% endcapture %}

{% capture whatsnext %}

{% endcapture %}

{% include templates/task.md %}