❄️ infrastructure

The dgnum infrastructure.

Contributing

Some instruction on how to contribute are available (in french) in /CONTRIBUTE.md. You're expected to read this document before commiting to the repo.

Some documentation for the development tools are provided in the aforementioned file.

Using the binary cache

Add the following module to your configuration (and pin this repo using your favorite tool: npins, lon, etc...):

{ lib, ... }:
let
  dgnum-infra = PINNED_PATH_TO_INFRA;
in {
  nix.settings = (import dgnum-infra { }).mkCacheSettings {
    caches = [ "infra" ];
  };
}

Adding a new machine

The first step is to create a minimal viable NixOS host, using tha means necessary. The second step is to find a name for this host, it must be unique from the other hosts.

Tip

For the rest of this part, we assume that the host is named host02

Download the keys

The public SSH keys of host02 have to be saved to keys, preferably only the ssh-ed25519 one.

It can be retreived with :

ssh-keyscan address.of.host02 2>/dev/null | awk '/ssh-ed25519/ {print $2,$3}'

Initialize the machine folder and configuration

• Create a folder host02 under machines/
• Copy the hardware configuration file generated by nixos-generate-config to machines/host02/_hardware-configuration.nix
• Create a machines/host02/_configuration.nix file, it will contain the main configuration options, the basic content of this file should be the following

{ lib, ... }:

lib.extra.mkConfig {
  enabledModules = [
    # List of modules to enable
  ];

  enabledServices = [
    # List of services to enable
  ];

  extraConfig = {
    services.netbird.enable = true;
  };

  root = ./.;
}

Fill in the metadata

Network configuration

The network is declared in meta/network.nix, the necessary hostId value can be generated with :

head -c4 /dev/urandom | od -A none -t x4 | sed 's/ //'

Other details

The general metadata is declared in meta/nodes.nix, the main values to declare are :

• site, where the node is physically located
• stateVersion
• nixpkgs, the nixpkgs version to use

Initialize secrets

Create the directory secrets in the configuration folder, and add a secrets.nix file containing :

(import ../../../keys.nix).mkSecrets [ "host02" ] [
  # List of secrets for host02
]

This will be used for future secret management.

Update encrypted files

Both the Arkheon, Netbox and notification modules have secrets that are deployed on all machines. To make those services work correctly, run in modules/dgn-records, modules/dgn-netbox-agent and modules/dgn-notify :

agenix -r

Commit and create a PR

Once all of this is done, check that the configuration builds correctly :

colmena build --on host02

Apply it, and create a Pull Request.