Here's a snapshot of the services I'm currently running for myself, and approximately how. Some will go, new ones will be added, but here we are for December 2024.

Many, if not all are strictly unnecessary, there are free/cheap hosted alternatives available, but there's something very satisfying about knowing these are sitting on a shelf in the cupboard in my office. Not least that for the most part, these services are incredibly responsive!

In the past I've run a lot of these things in a single-node Kubernetes cluster, mostly using Helm charts. NixOS modules have made things much simpler, whilst still allowing a declarative approach to managing most of these services.

I typically have /services/<service>/<subcomponent> directories on host machines, and have these mounted into the various containers and VMs as necessary to store state. This means the rest of the container/VM is usually ephemeral, and can be re-created at any time. Indeed, I've been able to migrate between machines very easily thanks to this. It also provides a gives me a single volume to back up from each host.

I recently got to grips with microvm.nix, so am starting to migrate things to VMs where that level of isolation feels appropriate.

One thing to be mindful of when using a single Nix expression to define a system composed of many containers/VMs is that nixos-rebuild is pretty expensive in CPU and RAM, taking around 2 minutes to make a simple change and using approaching 10Gb RAM on the machine that hosts the majority of the services below!