cc-ci-orchestrator/nix/hosts/cc-ci-orchestrator-hetzner/configuration.nix

# cc-ci-orchestrator-hetzner — NixOS config for the Hetzner loops runtime host.
#
# Purpose: run the cc-ci Builder/Adversary/Watchdog loops + orchestrator/assistant sessions
# on a Hetzner cpx11 (2 vCPU / 2 GB dedicated AMD / 40 GB NVMe), replacing the slow b1 Incus VM.
#
# Provision with terraform/ then converge with: nixos-rebuild switch --flake .#cc-ci-orchestrator-hetzner
# See terraform/README.md for the full Stage 2 procedure.
{ config, pkgs, lib, ... }:
{
  # hardware.nix is the nixos-infect generated hardware-configuration.nix (see README Stage 2a).

  services.openssh = {
    enable = true;
    settings.PermitRootLogin = "yes";
  };

  # Root SSH access (the cc-ci-root-ed25519 key used by all loops tooling).
  users.users.root.openssh.authorizedKeys.keys = [
    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAcyTGb/wVgdhg5oBCZZvBaR1RuUQRY/3WHnOQpNDCsp claude-cc-ci-sandbox@20260526"
  ];
  networking.useDHCP = true;
  networking.nameservers = [ "1.1.1.1" "8.8.8.8" ];
  networking.firewall = {
    enable = true;
    trustedInterfaces = [ "tailscale0" ];
    allowedTCPPorts = [ 22 ];
  };
  nix.settings.experimental-features = [ "nix-command" "flakes" ];
  system.stateVersion = "24.11";

  # Tailscale — auth key at /etc/ts-auth-key (placed manually in Stage 2, not in git).
  services.tailscale = {
    enable = true;
    authKeyFile = "/etc/ts-auth-key";
    extraUpFlags = [ "--hostname=cc-ci-orchestrator" "--ssh" ];
  };

  # 4 GB disk swap — claude session memory safety net (2 GB RAM is tight for 3+ sessions).
  swapDevices = [ { device = "/swapfile"; size = 4096; } ];

  # nix-ld — lets the standalone Claude Code CLI (foreign dynamic ELF / Bun) run on NixOS.
  programs.nix-ld.enable = true;
  programs.nix-ld.libraries = with pkgs; [
    stdenv.cc.cc.lib
    zlib
    openssl
    curl
    glibc
  ];

  environment.systemPackages = with pkgs; [
    git tmux python3 jq curl cacert
    gnused gawk coreutils gnugrep findutils util-linux
    nettools openssh
    age sops                # key management (same toolchain as cc-ci server)
  ];

  # loops user — claude sessions run as non-root (--dangerously-skip-permissions blocked for root).
  users.users.loops = {
    isNormalUser = true;
    home = "/home/loops";
    shell = pkgs.bash;
    extraGroups = [ "wheel" ];
  };
  security.sudo.wheelNeedsPassword = false;
  security.sudo.extraRules = [{
    users = [ "loops" ];
    commands = [{ command = "ALL"; options = [ "NOPASSWD" ]; }];
  }];

  # Ensure /home/loops/.local/bin (claude) is on the loops user PATH.
  environment.variables.PATH = lib.mkForce
    "/home/loops/.local/bin:/run/current-system/sw/bin:/run/wrappers/bin:/usr/bin:/bin";

  # SSH config for the loops user — points to the cc-ci Hetzner server via tailnet.
  # HostName is updated post-cutover to the Hetzner cc-ci tailnet IP.
  system.activationScripts.loopsSshConfig = ''
    mkdir -p /home/loops/.ssh && chown loops:users /home/loops/.ssh && chmod 700 /home/loops/.ssh
    # Only write if not already present (preserves manual customisation).
    if [ ! -f /home/loops/.ssh/config ]; then
      cat > /home/loops/.ssh/config <<'SSHCFG'
Host cc-ci
    HostName REPLACE_WITH_CC_CI_HETZNER_TAILNET_IP
    User root
    IdentityFile /home/loops/.ssh/cc-ci-root-ed25519
    IdentitiesOnly yes
    StrictHostKeyChecking accept-new
    ServerAliveInterval 30
SSHCFG
      chmod 600 /home/loops/.ssh/config
      chown loops:users /home/loops/.ssh/config
    fi
  '';

  # claude-install — fetch the standalone Claude Code CLI for the loops user if missing.
  systemd.services.claude-install = {
    description = "Install Claude Code CLI for loops user (idempotent)";
    wantedBy = [ "multi-user.target" ];
    after = [ "network-online.target" ];
    wants = [ "network-online.target" ];
    serviceConfig = {
      Type = "oneshot"; RemainAfterExit = true;
      User = "loops"; Group = "users";
    };
    environment = { HOME = "/home/loops"; };
    path = [ pkgs.curl pkgs.bash pkgs.coreutils pkgs.gnutar pkgs.gzip ];
    script = ''
      if [ ! -x "$HOME/.local/bin/claude" ]; then
        echo "installing Claude Code CLI for loops user..."
        curl -fsSL https://claude.ai/install.sh | bash || echo "install failed — retry on next activation"
      fi
    '';
  };

  # cc-ci-loops supervisor — defined but NOT enabled until workspace is staged.
  # Enable by adding wantedBy after staging (Stage 2e) for reboot-resilience.
  systemd.services.cc-ci-loops = {
    description = "cc-ci Builder/Adversary loops + watchdog (launch.sh start)";
    # wantedBy = [ "multi-user.target" ];  # uncomment after workspace is staged
    after = [ "network-online.target" "tailscaled.service" "claude-install.service" ];
    wants = [ "network-online.target" ];
    serviceConfig = {
      Type = "oneshot"; RemainAfterExit = true;
      User = "loops"; Group = "users";
      WorkingDirectory = "/srv/cc-ci";
    };
    environment = { RESUME_PHASE = "1"; HOME = "/home/loops"; };
    path = [ pkgs.bash pkgs.tmux pkgs.git pkgs.python3 pkgs.openssh pkgs.nettools ];
    script = ''
      [ -x /srv/cc-ci/cc-ci-plan/launch.sh ] && /srv/cc-ci/cc-ci-plan/launch.sh start || \
        echo "workspace not staged yet — skipping loop start"
    '';
  };
}