nixos/applications/prometheus.nix

{
  nodes,
  lib,
  config,
  ...
}:
with lib; let
  name = "prometheus";
  cfg = config.services.skynet."${name}";
in {
  imports = [];

  options.services.skynet."${name}" = {
    server = {
      enable = mkEnableOption "Prometheus Server";
      host = {
        ip = mkOption {
          type = types.str;
        };

        name = mkOption {
          type = types.str;
        };
      };

      port = mkOption {
        type = types.port;
        default = 9001;
      };

      other_nodes = mkOption {
        type = types.listOf types.str;
        description = ''
          To add other nodes outside of nix, specify ip and port that server should listen to here
        '';
      };
    };

    port_collecter = mkOption {
      type = types.port;
      default = 9002;
    };
  };

  config =
    {
      services.prometheus.exporters.node = {
        enable = true;
        # most collectors are on by default see docs for more options
        enabledCollectors = ["systemd"];
        port = cfg.port_collecter;
      };
    }
    // mkIf cfg.server.enable {
      services.prometheus = {
        enable = true;
        port = cfg.server.port;
        scrapeConfigs = [
          {
            job_name = "node_exporter";
            static_configs = [
              {
                targets = (map (hostname: "${hostname}:${cfg.port_collecter}") (lib.attrsets.mapAttrsToList (server: server.deployment.hostname)) nodes) ++ cfg.other_nodes;
              }
            ];
          }
        ];
      };
    };
}