Add uptime module

Signed-off-by: Shea Levy <shea@shealevy.com>

modules/module-list.nix

@@ -124,6 +124,7 @@
   ./services/monitoring/smartd.nix
   ./services/monitoring/systemhealth.nix
   ./services/monitoring/ups.nix
+  ./services/monitoring/uptime.nix
   ./services/monitoring/zabbix-agent.nix
   ./services/monitoring/zabbix-server.nix
   ./services/network-filesystems/drbd.nix

modules/services/monitoring/uptime.nix

@@ -0,0 +1,95 @@
+{ config, pkgs, ... }:
+let
+  inherit (pkgs.lib) mkOption mkEnableOption mkIf mkMerge types optionalAttrs optional;
+
+  cfg = config.services.uptime;
+
+  configDir = pkgs.runCommand "config" {} (if cfg.configFile != null then ''
+    mkdir $out
+    ext=`echo ${cfg.configFile} | grep -o \\..*`
+    ln -sv ${cfg.configFile} $out/default$ext
+    ln -sv /var/lib/uptime/runtime.json $out/runtime.json
+  '' else ''
+    mkdir $out
+    cat ${pkgs.nodePackages.node-uptime}/node_modules/node-uptime/config/default.yaml > $out/default.yaml
+    cat >> $out/default.yaml <<EOF
+
+    autoStartMonitor: false
+
+    mongodb:
+      connectionString: 'mongodb://localhost/uptime'
+    EOF
+    ln -sv /var/lib/uptime/runtime.json $out/runtime.json
+  '');
+in {
+  options.services.uptime = {
+    configFile = mkOption {
+      description = ''
+        The uptime configuration file
+
+        If mongodb: server != localhost, please set usesRemoteMongo = true
+
+        If you only want to run the monitor, please set enableWebService = false
+        and enableSeparateMonitoringService = true
+
+        If autoStartMonitor: false (recommended) and you want to run both
+        services, please set enableSeparateMonitoringService = true
+      '';
+
+      type = types.nullOr types.path;
+
+      default = null;
+    };
+
+    usesRemoteMongo = mkOption {
+      description = "Whether the configuration file specifies a remote mongo instance";
+
+      default = false;
+
+      type = types.bool;
+    };
+
+    enableWebService = mkEnableOption "the uptime web service";
+
+    enableSeparateMonitoringService = mkEnableOption "the uptime monitoring service (default: enableWebService == true)" // { default = cfg.enableWebService; };
+
+    nodeEnv = mkOption {
+      description = "The node environment to run in (development, production, etc.)";
+
+      type = types.string;
+
+      default = "production";
+    };
+  };
+
+  config = mkMerge [ (mkIf cfg.enableWebService {
+    systemd.services.uptime = {
+      description = "uptime web service";
+      wantedBy = [ "multi-user.target" ];
+      environment = {
+        NODE_CONFIG_DIR = configDir;
+        NODE_ENV = cfg.nodeEnv;
+        NODE_PATH = "${pkgs.nodePackages.node-uptime}/node_modules/node-uptime/node_modules";
+      };
+      preStart = "mkdir -p /var/lib/uptime";
+      serviceConfig.ExecStart = "${pkgs.nodejs}/bin/node ${pkgs.nodePackages.node-uptime}/node_modules/node-uptime/app.js";
+    };
+
+    services.mongodb.enable = mkIf (!cfg.usesRemoteMongo) true;
+  }) (mkIf cfg.enableSeparateMonitoringService {
+    systemd.services.uptime-monitor = {
+      description = "uptime monitoring service";
+      wantedBy = [ "multi-user.target" ];
+      requires = optional cfg.enableWebService "uptime.service";
+      after = optional cfg.enableWebService "uptime.service";
+      environment = {
+        NODE_CONFIG_DIR = configDir;
+        NODE_ENV = cfg.nodeEnv;
+        NODE_PATH = "${pkgs.nodePackages.node-uptime}/node_modules/node-uptime/node_modules";
+      };
+      # Ugh, need to wait for web service to be up
+      preStart = if cfg.enableWebService then "sleep 1s" else "mkdir -p /var/lib/uptime";
+      serviceConfig.ExecStart = "${pkgs.nodejs}/bin/node ${pkgs.nodePackages.node-uptime}/node_modules/node-uptime/monitor.js";
+    };
+  }) ];
+}