From c89117997db7f583592d1f7561df53b68138a4a4 Mon Sep 17 00:00:00 2001
From: Cole Helbling <cole.e.helbling@outlook.com>
Date: Mon, 1 Mar 2021 11:04:01 -0800
Subject: [PATCH] nixos/lifecycled: init

---
 nixos/modules/module-list.nix              |   1 +
 nixos/modules/services/misc/lifecycled.nix | 164 +++++++++++++++++++++
 2 files changed, 165 insertions(+)
 create mode 100644 nixos/modules/services/misc/lifecycled.nix

diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index d40edb2408f..f6fcd5a325b 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -490,6 +490,7 @@
   ./services/misc/logkeys.nix
   ./services/misc/leaps.nix
   ./services/misc/lidarr.nix
+  ./services/misc/lifecycled.nix
   ./services/misc/mame.nix
   ./services/misc/matrix-appservice-discord.nix
   ./services/misc/matrix-synapse.nix
diff --git a/nixos/modules/services/misc/lifecycled.nix b/nixos/modules/services/misc/lifecycled.nix
new file mode 100644
index 00000000000..1c8942998d6
--- /dev/null
+++ b/nixos/modules/services/misc/lifecycled.nix
@@ -0,0 +1,164 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+let
+  cfg = config.services.lifecycled;
+
+  # TODO: Add the ability to extend this with an rfc 42-like interface.
+  # In the meantime, one can modify the environment (as
+  # long as it's not overriding anything from here) with
+  # systemd.services.lifecycled.serviceConfig.Environment
+  configFile = pkgs.writeText "lifecycled" ''
+    LIFECYCLED_HANDLER=${cfg.handler}
+    ${lib.optionalString (cfg.cloudwatchGroup != null) "LIFECYCLED_CLOUDWATCH_GROUP=${cfg.cloudwatchGroup}"}
+    ${lib.optionalString (cfg.cloudwatchStream != null) "LIFECYCLED_CLOUDWATCH_STREAM=${cfg.cloudwatchStream}"}
+    ${lib.optionalString cfg.debug "LIFECYCLED_DEBUG=${lib.boolToString cfg.debug}"}
+    ${lib.optionalString (cfg.instanceId != null) "LIFECYCLED_INSTANCE_ID=${cfg.instanceId}"}
+    ${lib.optionalString cfg.json "LIFECYCLED_JSON=${lib.boolToString cfg.json}"}
+    ${lib.optionalString cfg.noSpot "LIFECYCLED_NO_SPOT=${lib.boolToString cfg.noSpot}"}
+    ${lib.optionalString (cfg.snsTopic != null) "LIFECYCLED_SNS_TOPIC=${cfg.snsTopic}"}
+    ${lib.optionalString (cfg.awsRegion != null) "AWS_REGION=${cfg.awsRegion}"}
+  '';
+in
+{
+  meta.maintainers = with maintainers; [ cole-h grahamc ];
+
+  options = {
+    services.lifecycled = {
+      enable = mkEnableOption "lifecycled";
+
+      queueCleaner = {
+        enable = mkEnableOption "lifecycled-queue-cleaner";
+
+        frequency = mkOption {
+          type = types.str;
+          default = "hourly";
+          description = ''
+            How often to trigger the queue cleaner.
+
+            NOTE: This string should be a valid value for a systemd
+            timer's <literal>OnCalendar</literal> configuration. See
+            <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+            for more information.
+          '';
+        };
+
+        parallel = mkOption {
+          type = types.ints.unsigned;
+          default = 20;
+          description = ''
+            The number of parallel deletes to run.
+          '';
+        };
+      };
+
+      instanceId = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          The instance ID to listen for events for.
+        '';
+      };
+
+      snsTopic = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          The SNS topic that receives events.
+        '';
+      };
+
+      noSpot = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Disable the spot termination listener.
+        '';
+      };
+
+      handler = mkOption {
+        type = types.path;
+        description = ''
+          The script to invoke to handle events.
+        '';
+      };
+
+      json = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable JSON logging.
+        '';
+      };
+
+      cloudwatchGroup = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          Write logs to a specific Cloudwatch Logs group.
+        '';
+      };
+
+      cloudwatchStream = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          Write logs to a specific Cloudwatch Logs stream. Defaults to the instance ID.
+        '';
+      };
+
+      debug = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable debugging information.
+        '';
+      };
+
+      # XXX: Can be removed if / when
+      # https://github.com/buildkite/lifecycled/pull/91 is merged.
+      awsRegion = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          The region used for accessing AWS services.
+        '';
+      };
+    };
+  };
+
+  ### Implementation ###
+
+  config = mkMerge [
+    (mkIf cfg.enable {
+      environment.etc."lifecycled".source = configFile;
+
+      systemd.packages = [ pkgs.lifecycled ];
+      systemd.services.lifecycled = {
+        wantedBy = [ "network-online.target" ];
+        restartTriggers = [ configFile ];
+      };
+    })
+
+    (mkIf cfg.queueCleaner.enable {
+      systemd.services.lifecycled-queue-cleaner = {
+        description = "Lifecycle Daemon Queue Cleaner";
+        environment = optionalAttrs (cfg.awsRegion != null) { AWS_REGION = cfg.awsRegion; };
+        serviceConfig = {
+          Type = "oneshot";
+          ExecStart = "${pkgs.lifecycled}/bin/lifecycled-queue-cleaner -parallel ${toString cfg.queueCleaner.parallel}";
+        };
+      };
+
+      systemd.timers.lifecycled-queue-cleaner = {
+        description = "Lifecycle Daemon Queue Cleaner Timer";
+        wantedBy = [ "timers.target" ];
+        after = [ "network-online.target" ];
+        timerConfig = {
+          Unit = "lifecycled-queue-cleaner.service";
+          OnCalendar = "${cfg.queueCleaner.frequency}";
+        };
+      };
+    })
+  ];
+}