Host-specific configuration + common modules that aren't better expressed as options & flake outputs. All hosts are configured with [agenix](https://github.com/ryantm/agenix), [disko](https://github.com/nix-community/disko), and [nixhw](https://github.com/alyraffauf/nixhw).
## Automatic Updates
These hosts update themselves automatically, once a day, by rebuilding from one of two sources: directly from this repository's master branch or from [FlakeHub](https://flakehub.com/). This can be adjusted by overriding the value of `config.environment.variables.FLAKE`.
FlakeHub allows [semantic versioning](https://flakehub.com/docs/features/semver), which means that these hosts build from the lattest tag published to FlakeHub with format `v0.0.0`. I try to follow the [semantic versioning 2.0](https://github.com/semver/semver/blob/master/semver.md) standard, though this may not always be the case.
You can access the latest tagged commit from this repository with this url: [https://flakehub.com/f/alyraffauf/nixcfg/\*.tar.gz](https://flakehub.com/f/alyraffauf/nixcfg/*.tar.gz).
## Declarative WiFi Connections
WiFi networks can be configured declaratiely in `wifi.nix` using `config.networking.networkmanager.ensureProfiles.profiles`, provided by nixpkgs. I also provide helper functions for common wifi security types.
[nm2nix](https://github.com/janik-haag/nm2nix) can generate nix code for all WiFi networks currently configured in `/etc/NetworkManager/system-connections/` and `/run/NetworkManager/system-connections` with the following command:
```bash
sudo su -c "cd /etc/NetworkManager/system-connections && nix --extra-experimental-features 'nix-command flakes' run github:Janik-Haag/nm2nix | nix --extra-experimental-features 'nix-command flakes' run nixpkgs#nixfmt-rfc-style"
```
Secrets (passwords, certificates, and identities) are supported, but must be declared and available as variables with agenix. They will be replaced upon activation with `envsubst`.
In short,
1. Manually configure the WiFi network on one device.
1. Export configuration to nix with `nm2nix`.
1. Add secrets to `secrets/wifi.age` as variables (e.g. `MYPSK=1234567890`)
1. Edit the code generated by `nm2nix` to reference `$MYPSK` instead of directly declaring the WPA password.
1. Commit and push changes.
1. Rebuild hosts as required to propogate your new WiFi configuration.
1. Create `hosts/$HOSTNAME/default.nix` and other host-specific nix modules (e.g. `disko.nix`,`hardware.nix`, and `home.nix`).
1. Add host to `nixosConfigurations` in `flake.nix`.
1. (OPTIONAL) Generate a `cert.pem`, `key.pem`, and device ID for Syncthing with `syncthing -generate=$HOSTNAME`. Find the device ID in the generated `config.xml` and add it to `nixosModules/services/syncthing/default.nix`, encrypt the cert and key with agenix, and set them as appropriate in the host configuration.
1. Install NixOS from this flake. Secrets will _not_ be available on first boot without a valid SSH private key.
1. On a separate PC, copy the new system's public SSH key (`/etc/ssh/ssh_host_ed25519_key.pub`) to the host configuration (`secrets/publicKeys/root_$HOSTNAME.pub`).
1. Add the new public key to `secrets/secrets.nix`, rekey all secrets with `agenix --rekey`, and push your changes to master.
1. Rebuild the new system from git. Secrets will be automatically decrypted and immediately available in `/run/agenix/` for NixOS and `$XDG_RUNTIME_DIR/agenix/` for users.
1. (OPTIONAL) Generate a new user SSH key and add it to `nixosModules/users/default.nix` in order to enable passwordless logins to other hosts.
