Database

So we'll start with database because I remember the least about it. First things first, I need persistence between restarts/updates, so I'll need to have volume mounted to the database pod. And service to expose it to the other applications on cluster.

After looking into persisted volumes on k8s I have to admit I had little to no luck having it setup in my desired way. I wanted that volume to be mounted on the local path inside project dir, or at least in some default location for volumes that I could reuse with a name or something similar. But in the end all I could find was how to provide absolute path. Not wasting more time on that I'm looking into something called stateful sets. And it seems that it's nothing different from using volumes. Although PersistentVolumeClaim looks somewhat promising. And seems that was the way to go. Have deployment, namespace, and PersistentVolumeClaim all green in dashboard. Time to create service and I'll done with database. Everything is almost verbatim copy from tutorial for Wordpress with MySQL in k8s docs.

Redis

This one shouldn't be that hard. I just need deployment and service running without any persistence (at least for now).

Application

This one forced me to reconsider my approach to persistence. As I mentioned I wanted to have DB volume mounted to to local path relative to project dir. But that would mean hard-coding full path, which is not feng shui even in local development. So rethinking it I decided to have somewhat of a template for k8s config, introduce Makefile to generate actual config from it, and have a command in it to generate it replacing placeholders with actual paths. All these shenanigans are necessary to have proper development environment, when I can edit code on my machine and have it executed in container (I really don't want to ssh into container to edit code).

So after dealing with persistence next thing on the list is to have PHP images built and pushed to local registry (which microk8s has and use to build pods). I have 2 options here on how to deal with images and deployments:

1. having single latest image and force microk8s to always pull it and also somehow force microk8s to trigger deployment update
2. have image with version tag (git commit hash) and update gitignore'ed k8s config with new image tag (that way I would for sure trigger deployment update when applying config):

Second option seems to be more hassle free. I already imagine 2 new Makefile commands to build image and push it to local registry. Image itself will be defined in Dockerfile, in docker directory inside project's root dir (there's a link to repo for all of this). And let's make it easier to manage with some commands in Makefile. And because of my setup I had to step on some rakes.

First of all getting "http://localhost:32000" that refuses connections didn't foreshadow anything good. At first I thought that it might be missing service in microk8s. Or some hiccup inside microk8s itself. So restarting registry addon didn't help. Maybe ingress addon is necessary for microk8s to accept requests? Not in this case. One of search results hinted me that I might be barking at the wrong tree. My microk8s is running inside multipass VM. And I need to use that machine's IP address instead of localhost. Typing 192.168.64.2:32000 in browser's address bar and it's working! So how do I get that IP address in cli? Some multipass info and grep can bring you a long way. But now podman makes HTTPS calls. So it seems like I'll be using podman machine ssh and add microk8s registry as insecure one. Image is now being built and sent to registry.

On to the next step which is create dummy PHP application, deploy to microk8s, and make it respond to requests from browser. Let's create Symfony project and check whether it's working.

symfony new api --version="^7.0" \
  && cd api \
  && symfony server:start

Opening it in browser shows me Symfony welcome page. So far so good. Now interesting part of k8s configs. Docker image will contain nothing except what is necessary to run Symfony application. Then I'm going to mount api dir to /var/www/html inside container. And that should work. Then there's only deployment, service, and ingress left. And how naive I was. I forgot that PHP-FPM needs reverse proxy to work. So that also needs nginx container running in same pod. And that too long to figure out. But in the end it's working. And it was too long ago to remember that /etc/hosts doesn't handle wildcards. I'm so out touch with devops stuff.

After battling layers of virtualisation, networking, and fpm/nginx I finally have app, that I can access from browser using domain name, and source running from my machine using mounted volumes. I also felt nostalgic about Ubuntu, where I had not to deal with multipass and could use Docker directly, didn't need to mount volumes to VM, so I could mount them to k8s pod.. Good old times.