{
  description = "hacc infra stuff";

  inputs = {
    mattermost-webapp.url = "https://releases.mattermost.com/6.7.2/mattermost-6.7.2-linux-amd64.tar.gz";
    mattermost-webapp.flake = false;
    mattermost-server.url = "github:mattermost/mattermost-server?ref=v6.7.2";
    mattermost-server.flake = false;

    nixpkgs.url = "nixpkgs/nixos-22.05";
    nixpkgs-unstable.url = "nixpkgs/nixpkgs-unstable";
    nix-hexchen.url = "gitlab:hexchen/nixfiles";
    nixos-mailserver.url = "gitlab:simple-nixos-mailserver/nixos-mailserver/nixos-22.05";

    deploy-rs.url = "github:serokell/deploy-rs";
    deploy-rs.inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = { self, nixpkgs, nix-hexchen, deploy-rs, ... }@inputs:
    let modules = nix-hexchen.nixosModules;
        profiles = nix-hexchen.nixosModules.profiles;
        pkgs = import ./pkgs {
          sources = inputs;
          system = "x86_64-linux";
        };
        # simulate the evalConfig as contained in nix-hexchen/lib/hosts.nix,
        # but compatible with flakes
        evalConfig = extraSpecial: config: nixpkgs.lib.nixosSystem {
          system = "x86_64-linux";
          modules = [
            config
            nix-hexchen.nixosModules.network.nftables
            { nixpkgs.pkgs = pkgs; }
          ];
          specialArgs = {
            inherit modules profiles evalConfig;
            sources = inputs;
          } // extraSpecial;
        };
    in {
      # do this by hand instead of via nix-hexchen/lib/hosts.nix, since that one
      # apparently can't support pkgs depending on flake inputs
      nixosConfigurations.parsons = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/parsons/configuration.nix
          # not used anymore, but other things in nix-hexchen still depend on it
          nix-hexchen.nixosModules.deploy
          { nixpkgs.pkgs = pkgs; }
        ];
        specialArgs = {
          # with a few exceptions, the flake inputs can be used the same
          # as the niv-style (import nix/sources.nix {})
          sources = inputs;
          inherit modules profiles evalConfig;
        };
      };

      deploy.nodes.parsons = {
        hostname = "parsons";
        profiles.system = {
          user = "root";
          autoRollback = false;
          path = deploy-rs.lib.x86_64-linux.activate.nixos
            self.nixosConfigurations.parsons;
        };
      };

      # This is highly advised, and will prevent many possible mistakes
      checks = builtins.mapAttrs
        (system: deployLib: deployLib.deployChecks self.deploy)
        deploy-rs.lib;
    };

}