This article proposes to automate the installation of Kubernetes 1.13 on Raspberry Pi via Ansible with a home-made role.

Prerequisites

Installation of Docker + Kubernetes

Retrieving the role
I have developed an ansible role for this automation, here’s how to retrieve it:

## Pré-requis Docker (rôle fait maison)
git clone https://gitlab.com/jls42/ansible-rpi-docker.git roles/ansible-rpi-docker
## Rôle pour l'installation de Kubernetes
git clone https://gitlab.com/jls42/ansible-rpi-k8s.git roles/ansible-rpi-k8s

For more details please see the documentation on ansible-rpi-k8s

Creation of the inventory file named inventory
In this example inventory, several Raspberry Pi 1 are listed, one with the IP 192.168.1.190 and the other with the IP 192.168.1.191
In the child group (here rpi-k8s), the master must be declared first

[rpi1]
192.168.1.190 k8s_master=true

[rpi2]
192.168.1.191

[rpi-k8s:children]
rpi1
rpi2

Preparation of the playbook k8s-rpi.yml

---
- name: "Installation de Docker sur le Raspberry Pi"
  hosts: rpi-k8s
  remote_user: "pi"
  roles:
    - roles/ansible-rpi-docker
  vars:
    docker_version: 18.06.1~ce~3-0~raspbian

- name: "Installation de k8s sur le Raspberry Pi"
  hosts: rpi-k8s
  remote_user: "pi"
  roles:
    - roles/ansible-rpi-k8s
  vars:
    k8s_version: "1.13.0-00"
    k8s_master_token: "abcdef.0123456789abcdef"
    k8s_cluster_group: rpi-k8s

Deployment of Docker and Kubernetes
The ansible roles ansible-rpi-docker and ansible-rpi-k8s will be executed in sequence.
In case Docker is already installed, it is possible to run only ansible-rpi-k8s.

export ANSIBLE_HOST_KEY_CHECKING=False
ansible-playbook -b -i inventory k8s-rpi.yml

Which gives:

jls42@boo:~/rpi$ ansible-playbook -b -i inventory k8s-rpi.yml

PLAY [Installation de Docker sur le Raspberry Pi] ******************************************************************************************************************************************************************************************

TASK [Gathering Facts] *********************************************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:26:30 +0100 (0:00:00.051)       0:00:00.051 *******
ok: [192.168.1.190]
ok: [192.168.1.191]

TASK [roles/ansible-rpi-docker : Installe les paquets nécessaire à l'utilisation d'un dépôt HTTPS] *****************************************************************************************************************************************
Sunday 09 December 2018  03:26:33 +0100 (0:00:03.476)       0:00:03.527 *******
changed: [192.168.1.190] => (item=[u'apt-transport-https', u'ca-certificates', u'curl', u'gnupg2', u'software-properties-common'])
changed: [192.168.1.191] => (item=[u'apt-transport-https', u'ca-certificates', u'curl', u'gnupg2', u'software-properties-common'])

TASK [roles/ansible-rpi-docker : Ajoute la clef officielle du dépôt Docker] ****************************************************************************************************************************************************************
Sunday 09 December 2018  03:27:12 +0100 (0:00:39.274)       0:00:42.802 *******
changed: [192.168.1.190]
changed: [192.168.1.191]

TASK [roles/ansible-rpi-docker : Ajoute le dépôt Docker] ***********************************************************************************************************************************************************************************
Sunday 09 December 2018  03:27:17 +0100 (0:00:04.747)       0:00:47.549 *******
changed: [192.168.1.190]
changed: [192.168.1.191]

TASK [roles/ansible-rpi-docker : Installe le paquet docker-ce] *****************************************************************************************************************************************************************************
Sunday 09 December 2018  03:27:27 +0100 (0:00:10.238)       0:00:57.788 *******
changed: [192.168.1.190]
changed: [192.168.1.191]

TASK [roles/ansible-rpi-docker : Installe python-pip] **************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:29:04 +0100 (0:01:36.285)       0:02:34.074 *******
changed: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-docker : Installe docker-compose via pip] **************************************************************************************************************************************************************************
Sunday 09 December 2018  03:30:06 +0100 (0:01:02.641)       0:03:36.715 *******
changed: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-docker : Configure Docker pour qu'il démarre au boot] **************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:03 +0100 (0:00:56.384)       0:04:33.099 *******
ok: [192.168.1.190]
ok: [192.168.1.191]

TASK [roles/ansible-rpi-docker : Ajoute l'utilisateur pi dans le groupe docker] ************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:04 +0100 (0:00:01.075)       0:04:34.175 *******
changed: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-docker : Supprime la swap] *****************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:05 +0100 (0:00:01.348)       0:04:35.523 *******
changed: [192.168.1.190]
changed: [192.168.1.191]
PLAY [Installation de k8s sur le Raspberry Pi] *********************************************************************************************************************************************************************************************

TASK [Gathering Facts] *********************************************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:07 +0100 (0:00:02.096)       0:04:37.620 *******
ok: [192.168.1.190]
ok: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Installe les paquets nécessaires à l'utilisation d'un dépôt HTTPS] *******************************************************************************************************************************************
Sunday 09 December 2018  03:31:09 +0100 (0:00:01.934)       0:04:39.555 *******
ok: [192.168.1.190] => (item=[u'apt-transport-https', u'ca-certificates', u'curl', u'gnupg2', u'software-properties-common'])
ok: [192.168.1.191] => (item=[u'apt-transport-https', u'ca-certificates', u'curl', u'gnupg2', u'software-properties-common'])

TASK [roles/ansible-rpi-k8s : Supprime la swap] ********************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:15 +0100 (0:00:05.740)       0:04:45.295 *******
ok: [192.168.1.190]
ok: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Active cgroup_memory] ****************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:16 +0100 (0:00:00.966)       0:04:46.262 *******
changed: [192.168.1.190]
changed: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Redémarre] ***************************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:17 +0100 (0:00:01.032)       0:04:47.295 *******
changed: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Attente suite au redémarrage] ********************************************************************************************************************************************************************************
Sunday 09 December 2018  03:31:18 +0100 (0:00:01.667)       0:04:48.962 *******
ok: [192.168.1.190]
ok: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Ajoute la clef officielle Kubernetes] ************************************************************************************************************************************************************************
Sunday 09 December 2018  03:32:19 +0100 (0:01:00.447)       0:05:49.409 *******
changed: [192.168.1.190]
changed: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Ajoute le dépôt stable de Kubernetes] ************************************************************************************************************************************************************************
Sunday 09 December 2018  03:32:25 +0100 (0:00:06.282)       0:05:55.692 *******
changed: [192.168.1.190]
changed: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Installe kubeadm, kubelet and kubectl] ***********************************************************************************************************************************************************************
Sunday 09 December 2018  03:32:45 +0100 (0:00:20.277)       0:06:15.970 *******
changed: [192.168.1.190] => (item=[u'kubeadm=1.13.0-00', u'kubelet=1.13.0-00', u'kubectl=1.13.0-00'])
changed: [192.168.1.191] => (item=[u'kubeadm=1.13.0-00', u'kubelet=1.13.0-00', u'kubectl=1.13.0-00'])

TASK [roles/ansible-rpi-k8s : Configure kubelet pour qu'il démarre au boot] ****************************************************************************************************************************************************************
Sunday 09 December 2018  03:34:25 +0100 (0:01:39.895)       0:07:55.865 *******
ok: [192.168.1.191]
ok: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Installe les paquets nécessaires pour l'utilisation du client CIFS] ******************************************************************************************************************************************
Sunday 09 December 2018  03:34:26 +0100 (0:00:01.029)       0:07:56.894 *******
changed: [192.168.1.191] => (item=[u'cifs-utils', u'util-linux', u'coreutils', u'jq'])
changed: [192.168.1.190] => (item=[u'cifs-utils', u'util-linux', u'coreutils', u'jq'])

TASK [roles/ansible-rpi-k8s : Ajout le répertoire d'addons cifs] ***************************************************************************************************************************************************************************
Sunday 09 December 2018  03:34:40 +0100 (0:00:13.835)       0:08:10.730 *******
changed: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Télécharge le plugin CIFS] ***********************************************************************************************************************************************************************************
Sunday 09 December 2018  03:34:41 +0100 (0:00:01.051)       0:08:11.782 *******
changed: [192.168.1.191]
changed: [192.168.1.190]
TASK [roles/ansible-rpi-k8s : Installe les paquets nécessaires à l'utilisation du client GlusterFS] *********************************************************************************************************************************************************
Sunday 09 December 2018  03:34:43 +0100 (0:00:01.740)       0:08:13.522 *******
changed: [192.168.1.190] => (item=[u'glusterfs-client'])
changed: [192.168.1.191] => (item=[u'glusterfs-client'])

TASK [roles/ansible-rpi-k8s : Définie l'ip du maître] **************************************************************************************************************************************************************************************
Sunday 09 December 2018  03:35:16 +0100 (0:00:32.640)       0:08:46.162 *******
ok: [192.168.1.190]
ok: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Vérifie si le master a déjà été configuré] *******************************************************************************************************************************************************************
Sunday 09 December 2018  03:35:16 +0100 (0:00:00.113)       0:08:46.276 *******
skipping: [192.168.1.191]
ok: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Définie l'initialisation du cluster à oui] *******************************************************************************************************************************************************************
Sunday 09 December 2018  03:35:17 +0100 (0:00:01.074)       0:08:47.350 *******
skipping: [192.168.1.191]
ok: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Définie l'initialisation du cluster à non] *******************************************************************************************************************************************************************
Sunday 09 December 2018  03:35:17 +0100 (0:00:00.113)       0:08:47.464 *******
skipping: [192.168.1.190]
skipping: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Définie l'initialisation du/des noeud(s)] ********************************************************************************************************************************************************************
Sunday 09 December 2018  03:35:17 +0100 (0:00:00.097)       0:08:47.562 *******
skipping: [192.168.1.190]
ok: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Initialise le cluster Kubernetes sur le maître] **************************************************************************************************************************************************************
Sunday 09 December 2018  03:35:17 +0100 (0:00:00.181)       0:08:47.743 *******
skipping: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Attend la fin de l'initialisation] ***************************************************************************************************************************************************************************
Sunday 09 December 2018  03:35:19 +0100 (0:00:01.598)       0:08:49.342 *******
skipping: [192.168.1.191]
FAILED - RETRYING: Attend la fin de l'initialisation (42 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (41 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (40 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (39 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (38 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (37 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (36 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (35 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (34 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (33 retries left).
FAILED - RETRYING: Attend la fin de l'initialisation (32 retries left).
changed: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Crée le répertoire kubernetes /home/pi/.kube/] ***************************************************************************************************************************************************************
Sunday 09 December 2018  03:41:02 +0100 (0:05:43.339)       0:14:32.682 *******
skipping: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Copie le fichier /etc/kubernetes/admin.conf vers /home/pi/.kube/config] **************************************************************************************************************************************
Sunday 09 December 2018  03:41:03 +0100 (0:00:00.948)       0:14:33.630 *******
skipping: [192.168.1.191]
changed: [192.168.1.190]

TASK [roles/ansible-rpi-k8s : Récupère la configuration kubernetes dans un répertoire local] ***********************************************************************************************************************************************
Sunday 09 December 2018  03:41:04 +0100 (0:00:01.030)       0:14:34.661 *******
skipping: [192.168.1.191]
changed: [192.168.1.190]
TASK [roles/ansible-rpi-k8s : Jointure de(s) noeud(s) avec le maître] **********************************************************************************************************************************************************************
Sunday 09 December 2018  03:41:05 +0100 (0:00:01.016)       0:14:35.678 *******
skipping: [192.168.1.190]
changed: [192.168.1.191]

TASK [roles/ansible-rpi-k8s : Installation des pods réseaux avec Weave] ********************************************************************************************************************************************************************
Sunday 09 December 2018  03:41:12 +0100 (0:00:06.567)       0:14:42.245 *******
skipping: [192.168.1.191]
changed: [192.168.1.190]

PLAY RECAP *********************************************************************************************************************************************************************************************************************************
192.168.1.190              : ok=33   changed=23   unreachable=0    failed=0   
192.168.1.191              : ok=27   changed=18   unreachable=0    failed=0   

Sunday 09 December 2018  03:41:18 +0100 (0:00:05.893)       0:14:48.139 *******
===============================================================================
roles/ansible-rpi-k8s ------------------------------------------------- 608.58s
roles/ansible-rpi-docker ---------------------------------------------- 274.09s
setup ------------------------------------------------------------------- 5.41s
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
total ----------------------------------------------------------------- 888.09s
Playbook run took 0 days, 0 hours, 14 minutes, 48 seconds

Verification

Connect to the Raspberry Pi to confirm the successful installation of Kubernetes
(the nodes may not all be in “Ready” state immediately, it can take a few minutes)

jls42@boo:~/rpi$ ssh pi@192.168.1.190
Linux rpi1 4.14.79-v7+ #1159 SMP Sun Nov 4 17:50:20 GMT 2018 armv7l

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Sun Dec  9 02:41:12 2018 from 192.168.1.42
pi@rpi1:~ $ kubectl get nodes -o wide
NAME   STATUS   ROLES    AGE    VERSION   INTERNAL-IP     EXTERNAL-IP   OS-IMAGE                         KERNEL-VERSION   CONTAINER-RUNTIME
rpi1   Ready    master   2m3s   v1.13.0   192.168.1.190   <none>        Raspbian GNU/Linux 9 (stretch)   4.14.79-v7+      docker://18.6.1
rpi2   Ready    <none>   85s    v1.13.0   192.168.1.191   <none>        Raspbian GNU/Linux 9 (stretch)   4.14.79-v7+      docker://18.6.1
pi@rpi1:~ $

And since the k8s configuration has been copied locally, it is also possible to run kubectl on the local machine (if it is installed).

Enjoy!

This document has been translated from the French version of the blog by the gpt-4-1106-preview model.