ansible-kubernetes-openshift-pi3 | Ansible playbooks for setting up a Kubernetes Raspberry Pi

Most of the installation is automated by using Ansible. Thanks to Hypriot images a complete headless setup is possible. "mysid" is your WLAN SID and "secret" the corresponding password. You will be asked to which device to write. Check this carefully, otherwise you could destroy your Desktop OS if selecting the the wrong device. Typically its something like /dev/disk2 on OS X, but depends on the number of hard drives you have.
Download the latest Hyoriot image and store it as hypriot.zip : curl -L https://github.com/hypriot/image-builder-rpi/releases/download/v1.7.1/hypriotos-rpi-v1.7.1.img.zip -o hypriot.zip
Install Hypriot's flash installer script. Follow the directions on the installation page. Important: For using the latest Hypriot Images >= 1.7.0 please use the Shell script from the master branch. The latest release 0.2.0 does not yet support the new configuration used by Hypriot 1.7.0. The script must be reachable from within your $PATH and it must be executable.
Insert you Micro-SD card in your Desktop computer (via an adapter possibly) and run the wrapper script
Repeat step 2. to 3. for each Micro SD card. Please adapt the hostname before each round to n1, n2, n3.
It is now time to configure your WLAN router. This of course depends on which router you use. The following instructions are based on a TP-Link TL-WR802N which is quite inexepensive but still absolutely ok for our purposes since it sits very close to the cluster and my notebook anyway. First of all you need to setup the SSID and password. Use the same credentials with which you have configured your images. My setup is, that I span a private network 192.168.23.0/24 for the Pi cluster which my MacBook also joins via its integrated WiFi.
If you have already created a cluster with these playbooks and want to start a fresh, please be sure that you cleanup your ~/.ssh/known_hosts from the old host keys. The script tools/cleanup_known_hosts.sh can be used for this. You should be able to ssh into each of the nodes without warnings. Also you must be able to reach the internet from the nodes. In the next step the basic setup (without Kubernetes) is performed. This is done by. When you are prompted for the password, use hypriot. You will probably also need to confirm the SSH authentity for each host with yes.
Docker will be installed from the Hypriot repositories
Your public SSH key .ssh/id_rsa.pub is copied over to pi's authenticated_keys and the users password will be taken from config.yml
Some extra tools are installed for your convenience and some benchmarking: hdparm iperf mtr vim dnsutils jq
Hostname is set to the name of the node configured. Also /etc/hosts is setup to contain all nodes with their short names.
The final step for a working Kubernetes cluster is to run. This will install one master at n0 and threed additional nodes n1, n2, n3 with the help of kubeadm.
Creates a token in run/kubeadm-token.txt if not done already and use it for installing master and nodes
Installs kubectl and an alias k
Creates a run/pi-cluster.cfg which can be used for kubectl on the local host to access the pi cluster's master. Either use kubectl --kubeconfig run/pi-cluster.cfg or set the environment variable export KUBECONFIG=$(pwd)/run/pi-cluster.cfg