sydnix/modules/nixos/gitea-actions-runner.nix

# Stolen from https://git.neet.dev/zuckerberg/nix-config/src/branch/master/common/server/gitea-actions-runner.nix
{ config, lib, pkgs, ... }:

let
  cfg = config.sydnix.gitea-actions-runner;
  token-file = config.sops.secrets.gitea-actions-runner-token.path;
in {
  options.sydnix.gitea-actions-runner = {
    enable = lib.mkEnableOption "Gitea actions runner";
    instance-name = lib.mkOption {
      type = lib.types.str;
      default = config.networking.hostName;
      description = ''
	The name of the runner instance name.
      '';
    };
    user.name = lib.mkOption {
      type = lib.types.str;
      default = "gitea-actions-runner";
      description = ''
	The name of the user gitea-actions-runner should run under.
      '';
    };
    user.uid = lib.mkOption {
      type = lib.types.int;
      default = 991;
      description = ''
	The UID of the user gitea-actions-runner should run under.
	This must be known at evaluation time so that the same UID can
	be used both on the host and in the container, allowing the
	container to access the host's nix-daemon.
      '';
    };
    group.name = lib.mkOption {
      type = lib.types.str;
      default = "gitea-actions-runner";
      description = ''
	The name of the group gitea-actions-runner should run under.
      '';
    };
    group.gid = lib.mkOption {
      type = lib.types.int;
      default = 989;
      description = ''
	The GID of the group gitea-actions-runner should run under.
	This must be known at evaluation time so that the same GID can
	be used both on the host and in the container, allowing the
	container to access the host's nix-daemon.
      '';
    };
  };

  config = lib.mkIf cfg.enable {
    sydnix.sops.secrets.gitea-actions-runner-token = {};

    sydnix.impermanence.directories = [ "/var/lib/gitea-actions-runner" ];

    containers."gitea-actions-runner" = {
      autoStart = true;
      ephemeral = true;

      bindMounts = {
        ${token-file} = {
          hostPath = token-file;
          isReadOnly = true;
        };
        "/var/lib/gitea-actions-runner" = {
          hostPath = "/var/lib/gitea-actions-runner";
          isReadOnly = false;
        };
      };

      config = { config, lib, pkgs, ... }: {
        system.stateVersion = "25.11";

        services.gitea-actions-runner.instances.${cfg.instance-name} = {
          enable = true;
          name = cfg.instance-name;
          url = "https://git.deertopia.net/";
          tokenFile = token-file;
          labels = [ "nixos:host" ];
	  hostPackages = with pkgs; [
	    bash
	    coreutils
	    curl
	    gawk
	    gitMinimal
	    gnused
	    nodejs
	    wget
	    nix
	  ];
        };

        # Disable dynamic user so runner state persists via bind mount
	assertions = [{
	  assertion =
	    config.systemd.services.gitea-actions-runner-sydpc.enable;
	  message = ''
	    Expected systemd service 'gitea-actions-runner-sydpc' is
	    not enabled — the gitea-actions-runner NixOS module may
	    have changed its naming scheme.
	  '';
	}];

        systemd.services.gitea-actions-runner-sydpc.serviceConfig.DynamicUser
	  = lib.mkForce false;

        users.users.${cfg.user.name} = {
          uid = cfg.user.uid;
          home = "/var/lib/gitea-actions-runner";
          group = cfg.group.name;
          isSystemUser = true;
          createHome = true;
        };

        users.groups.gitea-actions-runner.gid = cfg.group.gid;

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

        environment.systemPackages = with pkgs; [
          git
          nodejs
          jq
          attic-client
	  omnix
        ];
      };
    };

    # Needs to be outside of the container because container uses's
    # the host's nix-daemon
    nix.settings.trusted-users = [
      cfg.user.name
    ];

    # Matching user on host — the container's gitea-actions-runner UID
    # must be recognized by the host's nix-daemon as trusted (shared
    # UID namespace)
    users.users.${cfg.user.name} = {
      uid = cfg.user.uid;
      home = "/var/lib/gitea-actions-runner";
      group = cfg.group.name;
      isSystemUser = true;
      createHome = true;
    };
    users.groups.${cfg.group.name}.gid = cfg.group.gid;
  };
}