nixos-config/hosts/m3-hermes/services/hermes-dashboard.nix

{
  config,
  pkgs,
  inputs,
  ...
}: let
  # Netbird mesh VPN range — dashboard only accessible from mesh peers
  netbirdRange = "100.64.0.0/16";

  # Reference the hermes-agent package from the running service config
  hermesPkg = config.services.hermes-agent.package or (inputs.hermes-agent.packages.${pkgs.stdenv.hostPlatform.system}.default or pkgs.hermes-agent);
in {
  # ── Hermes Dashboard systemd service ───────────────────────────────────
  # Web UI for managing Hermes Agent — sessions, config, kanban, cron, etc.
  # Binds to 0.0.0.0:9119 but firewall restricts to Netbird mesh only.
  systemd.services.hermes-dashboard = {
    description = "Hermes Agent Web Dashboard";
    after = ["network.target" "hermes-agent.service"];
    wants = ["hermes-agent.service"];
    wantedBy = ["multi-user.target"];

    serviceConfig = {
      Type = "simple";
      User = "hermes";
      Group = "hermes";

      # --insecure: required to bind 0.0.0.0 (default refuses non-localhost).
      # Safe because firewall restricts port 9119 to Netbird mesh only.
      ExecStart = "${hermesPkg}/bin/hermes dashboard --host 0.0.0.0 --port 9119 --no-open --insecure";

      # Environment matching the hermes-agent service
      Environment = [
        "HERMES_HOME=/var/lib/hermes/.hermes"
        "HERMES_MANAGED=true"
        "HOME=/var/lib/hermes"
      ];

      # Security hardening (matching hermes-agent service pattern)
      NoNewPrivileges = true;
      ProtectSystem = "strict";
      ProtectHome = "read-only";
      ReadWritePaths = ["/var/lib/hermes" "/tmp"];
      PrivateTmp = true;

      # Restart policy
      Restart = "on-failure";
      RestartSec = 5;
    };
  };

  # ── Firewall: Dashboard only from Netbird mesh ─────────────────────────
  networking.firewall = {
    # Use extraCommands for source-IP-restricted port (NixOS firewall
    # allowedTCPPorts is all-or-nothing per port).
    extraCommands = ''
      # Allow Hermes Dashboard (9119/tcp) only from Netbird mesh VPN
      ip46tables -A nixos-fw -p tcp --dport 9119 -s ${netbirdRange} -j nixos-fw-accept
    '';

    extraStopCommands = ''
      ip46tables -D nixos-fw -p tcp --dport 9119 -s ${netbirdRange} -j nixos-fw-accept 2>/dev/null || true
    '';
  };
}