nixos-vps/configuration.nix

{ config, pkgs, lib, ... }: {
  imports = [
    ./hardware-configuration.nix
  ];

  # Workaround for https://github.com/NixOS/nix/issues/8502
  services.logrotate.checkConfig = false;

  boot.tmp.cleanOnBoot = true;
  zramSwap = {
    enable = true;
    memoryPercent = 50;
    algorithm = "zstd";
  };
  networking.hostName = "nixos";
  networking.domain = "";

  # === Firewall ===
  networking.firewall = {
    enable = true;
    allowedTCPPorts = [ 22 ]; # SSH (80/443 added by nginx module)
    allowPing = false;
  };

  # === SSH Hardening ===
  services.openssh = {
    enable = true;
    settings = {
      PermitRootLogin = "no";
      PasswordAuthentication = false;
      KexAlgorithms = [
        "sntrup761x25519-sha512@openssh.com"
        "curve25519-sha256"
        "curve25519-sha256@libssh.org"
      ];
      Ciphers = [
        "chacha20-poly1305@openssh.com"
        "aes256-gcm@openssh.com"
      ];
      Macs = [
        "hmac-sha2-512-etm@openssh.com"
        "hmac-sha2-256-etm@openssh.com"
        "umac-128-etm@openssh.com"
      ];
    };
  };

  # === User Account ===
  users.users.ashie = {
    isNormalUser = true;
    extraGroups = [ "wheel" ];
    openssh.authorizedKeys.keys = [
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAII0OjmlFPbz/H0sv+Y7L+rHR7KCD9lL7HIevEnqy48qH ashisgreat22@github.com"
    ];
  };

  # === Sudo without password for wheel group ===
  security.sudo.wheelNeedsPassword = false;

  # === SOPS (Secrets Management) ===
  sops = {
    defaultSopsFile = ./secrets/secrets.yaml;
    defaultSopsFormat = "yaml";
    age.keyFile = "/var/lib/sops-nix/key.txt";
    # Generate with: nix-shell -p age --run "age-keygen -o key.txt"
    # Then add the public key to .sops.yaml
  };

  # === System Maintenance & Updates ===
  myModules.system = {
    mainUser = "ashie";
    autoUpdate = {
      enable = true;
      allowReboot = false; # Set to true to allow automatic reboots for kernel updates
    };
  };

  system.stateVersion = "23.11";

  environment.systemPackages = with pkgs; [
    vim
    wget
    git
    nano
    kitty.terminfo
    htop
    tmux
    headscale
  ];

  nix.settings.experimental-features = [ "nix-command" "flakes" ];

  # === Websurfx (replaces SearXNG) ===
  myModules.websurfx = {
    enable = true;
    port = 8888;
    domain = "search.ashisgreat.xyz";
    threads = 8;
    theme = "simple";
    colorscheme = "catppuccin-mocha";
  };

  # === Nginx Reverse Proxy ===
  myModules.nginx = {
    enable = true;
    email = "info@ashisgreat.xyz";
    rateLimit = {
      enable = true;
      requests = 10;
      burst = 20;
    };
    domains = {
      "search.ashisgreat.xyz" = {
        port = 8888;
        # SearXNG sets its own CSP in settings.yml — omit at Nginx level to avoid conflicts
        contentSecurityPolicy = null;
        # Search engine — slightly more permissive for bot traffic
        rateLimit.requests = 20;
        rateLimit.burst = 40;
      };
    };
  };

  # === AdGuard Home (DoT) ===
  myModules.adguard = {
    enable = true;
    domain = "dns.ashisgreat.xyz";
  };

  # === OpenClaw ===
  myModules.openclaw-podman = {
    enable = true;
    port = 18789;
    domain = "openclaw.ashisgreat.xyz";
  };

  # OpenClaw secrets
  sops.secrets.openclaw_discord_token = { };
  sops.secrets.openclaw_zai_api_key = { };
  sops.secrets.openclaw_brave_api_key = { };
  sops.secrets.github_token = { };
  sops.secrets.forgejo_url = { };
  sops.secrets.forgejo_token = { };
  sops.secrets.forgejo_user = { };

  sops.templates."openclaw.env" = {
    content = ''
      DISCORD_TOKEN=${config.sops.placeholder.openclaw_discord_token}
      ZAI_API_KEY=${config.sops.placeholder.openclaw_zai_api_key}
      BRAVE_API_KEY=${config.sops.placeholder.openclaw_brave_api_key}
      GITHUB_TOKEN=${config.sops.placeholder.github_token}
      FORGEJO_URL=${config.sops.placeholder.forgejo_url}
      FORGEJO_TOKEN=${config.sops.placeholder.forgejo_token}
      FORGEJO_USER=${config.sops.placeholder.forgejo_user}
    '';
  };

  # === Vaultwarden ===
  myModules.vaultwarden = {
    enable = true;
    domain = "vault.ashisgreat.xyz";
    signupAllowed = false;
  };

  # === Forgejo (Self-hosted Git) ===
  myModules.forgejo = {
    enable = true;
    domain = "git.ashisgreat.xyz";
    disableRegistration = true; # Admin only
    runner = {
      enable = true;
      tokenFile = config.sops.templates."forgejo-runner.env".path;
    };
  };

  # Forgejo runner secrets
  sops.secrets.forgejo_runner_token = { };
  sops.templates."forgejo-runner.env" = {
    content = ''
      TOKEN=${config.sops.placeholder.forgejo_runner_token}
    '';
  };

  # === CrowdSec ===
  myModules.crowdsec.enable = true;

  # === Headscale (Self-hosted Tailscale) ===
  myModules.headscale = {
    enable = true;
    domain = "vpn.ashisgreat.xyz";
    # OIDC not enabled by default — use pre-shared auth keys:
    #   headscale apikeys create
    #   tailscale up --login-server=https://vpn.ashisgreat.xyz --authkey=<key>
    #
    # To enable OIDC login (Google, GitHub, etc.):
    #   oidc.enable = true;
    #   oidc.issuer = "https://accounts.google.com";
    #   oidc.clientId = "your-client-id";
    #   oidc.clientSecret = config.sops.placeholder.headscale_oidc_secret;
    # And add headscale_oidc_secret to your secrets.yaml
  };

  # === Tailscale Client ===
  services.tailscale.enable = true;

  # === Backups (Restic + B2) ===
  myModules.backup = {
    enable = true;
    repository = "b2:nixos-vps-backup2";
    paths = [
      "/var/lib/vaultwarden"         # Vaultwarden SQLite DB and attachments
      "/var/backup/vaultwarden"      # Vaultwarden built-in backup snapshots
      "/var/lib/private/AdGuardHome" # AdGuard Home config, filters, query logs
      "/var/lib/sops-nix"           # SOPS age key (critical — decrypts all secrets)
      "/var/lib/crowdsec"           # CrowdSec state, decisions, custom parsers
    ];
  };
}