Git repository management

git.nix

{ config, pkgs, ... }:

with pkgs.lib;

let

  mainCfg = config.services.git;

  repositoryOpts = { name, config, ... }: {
    
    options = {
    
      name = mkOption {
        type = with types; uniq string;
        description = "";
      };

      users = mkOption {
        type = with types; listOf string;
        default = [];
        description = "";
      };

    };

    config = {
      name = mkDefault name;
    };

  };

  repositories = concatStrings (map (r: "${r.name} ")
    (attrValues mainCfg.repositories));

in {

  options.services.git = {

    enable = mkOption {
      default = false;
      description = "";
    };

    user = mkOption {
      default = "git";
      description = "";
    };

    group = mkOption {
      default = "git";
      description = "";
    };

    repositories = mkOption {
      default = {};
      type = types.loaOf types.optionSet;
      description = "";
       options = repositoryOpts;
    };

  };

  config = mkIf config.services.git.enable {

    environment.systemPackages = [ pkgs.git ];

    users.extraUsers = optionalAttrs (mainCfg.user == "git")
      (singleton { name = mainCfg.user; description = "Git user"; })
      ++ concatMap (r: map (u: { name = u; extraGroups = singleton "git-${r.name}"; }) r.users)
             (attrValues mainCfg.repositories);

    users.extraGroups = optionalAttrs (mainCfg.group == "git")
                          (singleton { name = "git"; })
                     ++ map (r: { name = "git-${r.name}"; })
                          (attrValues mainCfg.repositories);
    
    jobs.git = {

      startOn = "started network-interfaces";
      stopOn = "stopped network-interfaces";

      preStart = ''
        mkdir -m 750 -p /var/srv/git
        chown ${mainCfg.user}:${mainCfg.group} /var/srv/git
        for fn in ${repositories}; do
          mkdir -m 750 -p "/var/srv/git/$fn"
          chown ${mainCfg.user}:${mainCfg.group} "/var/srv/git/$fn"
        done
      '';

    };

  };

}