Kubernetes on Raspberry Pi 4 on Fedora

Recently, I bought a couple of Raspberry Pi 4, one with 4 GB and 2 equipped with 8 GB of RAM. When I bought the first one, there was no option to get bigger memory. However, I saw this as a game and thought to give this a try. I also bought SSDs for these and USB3 to SATA adapters. Before purchasing anything, you may want to take a look at James Archers page. Unfortunately, there are a couple on adapters on the marked, which don't work that well.

Deploying Fedora 33 Server

Initially, I followed the description to deploy Fedora 32; it works the same way for Fedora 33 Server (in my case here).

Because ceph requires a partition (or better: a whole disk), I used the traditional setup using partitions and no LVM.

Deploying Kubernetes

git clone https://github.com/kubernetes-sigs/kubespray
cd kubespray

I followed the documentation and created an inventory. For the container runtime, I picked crio, and as calico as network plugin.

Because of an issue, I had to patch roles/download/defaults/main.yml:

diff --git a/roles/download/defaults/main.yml b/roles/download/defaults/main.yml
index a97be5a6..d4abb341 100644
--- a/roles/download/defaults/main.yml
+++ b/roles/download/defaults/main.yml
@@ -64,7 +64,7 @@ quay_image_repo: "quay.io"

 # TODO(mattymo): Move calico versions to roles/network_plugins/calico/defaults
 # after migration to container download
-calico_version: "v3.16.5"
+calico_version: "v3.15.2"
 calico_ctl_version: "{{ calico_version }}"
 calico_cni_version: "{{ calico_version }}"
 calico_policy_version: "{{ calico_version }}"
@@ -520,13 +520,13 @@ etcd_image_tag: "{{ etcd_version }}{%- if image_arch != 'amd64' -%}-{{ image_arc
 flannel_image_repo: "{{ quay_image_repo }}/coreos/flannel"
 flannel_image_tag: "{{ flannel_version }}"
 calico_node_image_repo: "{{ quay_image_repo }}/calico/node"
-calico_node_image_tag: "{{ calico_version }}"
+calico_node_image_tag: "{{ calico_version }}-arm64"
 calico_cni_image_repo: "{{ quay_image_repo }}/calico/cni"
-calico_cni_image_tag: "{{ calico_cni_version }}"
+calico_cni_image_tag: "{{ calico_cni_version }}-arm64"
 calico_policy_image_repo: "{{ quay_image_repo }}/calico/kube-controllers"
-calico_policy_image_tag: "{{ calico_policy_version }}"
+calico_policy_image_tag: "{{ calico_policy_version }}-arm64"
 calico_typha_image_repo: "{{ quay_image_repo }}/calico/typha"
-calico_typha_image_tag: "{{ calico_typha_version }}"
+calico_typha_image_tag: "{{ calico_typha_version }}-arm64"
 pod_infra_image_repo: "{{ kube_image_repo }}/pause"
 pod_infra_image_tag: "{{ pod_infra_version }}"
 install_socat_image_repo: "{{ docker_image_repo }}/xueshanf/install-socat"

Deploy Ceph

Ceph requires a raw partition. Make sure, you have an empty partition available.

[root@node1 ~]# lsblk -f
│    vfat   FAT32 UEFI  7DC7-A592
│    vfat   FAT32       CB75-24A9                               567.9M     1% /boot/efi
│    xfs                cab851cb-1910-453b-ae98-f6a2abc7f0e0    804.7M    23% /boot
│    xfs                6618a668-f165-48cc-9441-98f4e2cc0340     27.6G    45% /

In my case, there are sda4 and sda6 not formatted. sda4 is very small and will be ignored, sda6 will be used.

Using rook is pretty straightforward

git clone --single-branch --branch v1.5.4 https://github.com/rook/rook.git
cd rook/cluster/examples/kubernetes/ceph
kubectl create -f crds.yaml -f common.yaml -f operator.yaml
kubectl create -f cluster.yaml