# nixos-servers

Nix definitions to configure our server.
Currently, our three main machines and all virtual machines run NixOS!

## Acknowledgements

- [deploy-rs](https://github.com/serokell/deploy-rs): NixOS deploy tool with rollback functionality
- [disko](https://github.com/nix-community/disko): declarative disk partitioning
- [agenix](https://github.com/ryantm/agenix): deployment of encrypted secrets to NixOS machines
- [dns.nix](https://github.com/kirelagin/dns.nix): A Nix DSL for defining DNS zones
- [microvm.nix](https://github.com/astro/microvm.nix): Declarative virtual machine management in NixOS

## Installation

### Prerequisites

1. Install the Nix package manager or NixOS ([link](https://nixos.org/download))
2. Enable flake and nix commands ([link](https://nixos.wiki/wiki/Flakes#Enable_flakes_permanently_in_NixOS))
3. Install Direnv ([link](https://direnv.net/))
4. Allow direnv for this repository: `direnv allow`

### Bootstrapping

We bootstrap our physical server using [nixos-anywhere](https://github.com/nix-community/nixos-anywhere).
This reformats the hard disk of the server and installs a fresh NixOS.
Additionally, it deploys an age identity, which is later used for decrypting secrets.

⚠️  This will wipe your server completely ⚠️

1. Make sure your have a [Secret service](https://www.gnu.org/software/emacs/manual/html_node/auth/Secret-Service-API.html) running (such as Keepassxc) that provides the age identity.
2. Ensure you have root SSH access to the server.
3. Run nixos-anywhere: `./bootstrap.sh <servername> <hostname>`

### Deployment

To deploy all servers at once: `deploy`
To deploy only one server: `deploy --targets .#<host>`

## Known bugs

When deploying a new virtiofs share, the error `Failed to connect to '<name>.sock': No such file or directory` can occur.
This seems to be a bug in `microvm.nix` and I opened a bug report [here](https://github.com/astro/microvm.nix/issues/200).
A workaround is to deploy the share without `deploy-rs`'s rollback feature enabled:
```
deploy --targets .#lewis --auto-rollback false --magic-rollback false
```

Currently the flake checks fail on Raspberry Pi because it tries to compile the deploy-rs binary in aarch64 format on the controller.
This can be temporarily circumvented by using `--skip-checks`.