On 8/1 I gave a presentation titled Intro to Kubernetes For Devops: From the perspective of a (somewhat) old dog for the IT Crowd - Naperville computer club. As usual, it was a lot of fun with a great group. What I basically did was create a quick Openfaas system and deploy a few functions on top of it. We then discussed what it was I actually did and a few basics about Kubernetes administation.

I recently installed my first Nextcloud server on top of a new Digital Ocean Kubernetes (K8S) cluster as a Kubernetes training exercise. I ended up learning a ton about Kubernetes but I also learned a lot about how to run a Nextcloud server. One thing I learned very quickly is that most default web server configurations don’t support uploading files larger than a few megabytes. I therefor got a ton of errors the first time I tried syncing an image folder.

The most confusing aspect of using Kubernetes for me is storage. I mean, they seem so simple, but take a look at this: apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mysql-nc-pv-claim labels: app: nextcloud spec: accessModes: - ReadWriteOnce resources: requests: storage: 5Gi Here’s some questions that jump to my mind: How is a Persistent Volume Claim (PVC) different than a Persistent Volume (PV)? Why do I only need a PVC sometimes?

I’m happy to say that I deployed my first “real”, public-facing app on top of a Kubernetes cluster. It’s a Nextcloud server and my host is Digital Ocean (DO). So far the experience has been very good and I’m very impressed the host and software stack. My deployment “code” is available here: https://github.com/tompurl/nextcloud-k8s The notes are pretty rough and the non-secrets are hard-coded for my needs, so I have a bit of work to do before most people can use it :-) However, it does a lot of cool things that you can’t find in the official Helm package:

kubectl Choosing the correct context First check out your available contexts like this: kubectl config get-contexts CURRENT NAME CLUSTER AUTHINFO NAMESPACE *do-toms-cluster do-toms-cluster do-toms-cluster-admin gke_symmetric-blade-21345 gke_symmetric-blade-21345 gke_symmetric-blade-21345 You can then choose the desired context like this: kubectl config use-context do-toms-cluster Merging Multiple Contexts https://stackoverflow.com/a/46184649/1380901 k3s How to run kubeconfig At first it’s best to run kubeconfig from the k3s server itself. Here’s a nice alias for it: alias kubectl='sudo k3s kubectl' Helm Installation of a Chart First grab the values like thes:

Background Today I upgrading my Nextcloud server from version 18 to 19 by simply changing the Docker image version tag like so: kubectl --record deployment.apps/nextcloud set image deployment.v1.apps/nextcloud nextcloud=nextcloud:19.0.0-apache After waiting for my Nextcloud pod to start I got a 503 error from Nginx. Hmm I thought, this must be a secrets issue since I usually update the deployment using the following command: kubectl apply -k ./ I therefore updated the version tag for the Nextcloud image in my YAML file and ran that command and waited for the pod to start.