K3S on Raspberry Pi 4 - kubectl outside cluster
December 19, 2023
Now that I have a cluster set up (see https://drumcoder.co.uk/blog/2023/dec/19/k3s-on-raspberry-pi-4-initial-setup/ for setup details) I wanted to be able to access it from my mac, without sshing into the cluster master node.
Installing kubectl
The kubectl command can be installed on a mac using:
$ brew install kubectl
Install can be confirmed by running
$ kubectl version --client
Client Version: v1.29.0
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
At this point, we're not connected to the cluster, so this command will just sit there before failing with a timeout
$ kubectl cluster-info
E1219 11:59:06.947565 3078 memcache.go:265] couldn't get current server API group list:
Get "https://192.168.1.10:6443/api?timeout=32s": dial tcp 192.168.1.10:6443: i/o timeout
Connecting to the cluster
So now we need to connect our local kubectl to the cluster.
On the master node, we need the contents of the file at /etc/rancher/k3s/k3s.yaml, and we need to copy this into a local file on the mac - ~/.kube/config, whilst changing the line the starts server so that is has the correct IP for our master node. I ended up with a file that looked like this:
apiVersion: v1
kind: Config
preferences: {}
clusters:
- name: k3s-cluster
cluster:
certificate-authority-data: LS..0K
server: https://192.168.1.20:6443
contexts:
- name: k3s
context:
cluster: k3s-cluster
user: k3s-admin
current-context: k3s
users:
- name: k3s-admin
user:
client-certificate-data: LS..0K
client-key-data: LS..oa
So now we get check that we can access the cluster:
:::text
$ kubectl cluster-info
Kubernetes control plane is running at https://192.168.1.20:6443
CoreDNS is running at https://192.168.1.20:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
Metrics-server is running at https://192.168.1.20:6443/api/v1/namespaces/kube-system/services/https:metrics-server:https/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
