modules/drumknotty: wrap services in infinite loops

flake.nix

@@ -197,7 +197,6 @@
             inputs.pvv-calendar-bot.nixosModules.default
             inputs.minecraft-heatmap.nixosModules.default
             self.nixosModules.gickup
-            self.nixosModules.hugepages
             self.nixosModules.matrix-ooye
           ];
           overlays = [
@@ -310,7 +309,6 @@
       bluemap = ./modules/bluemap.nix;
       drumknotty = ./modules/drumknotty;
       gickup = ./modules/gickup;
-      hugepages = ./modules/hugepages.nix;
       matrix-ooye = ./modules/matrix-ooye.nix;
       python-http-handlers = ./modules/python-http-handlers.nix;
       robots-txt = ./modules/robots-txt.nix;

hosts/bicep/services/mysql/default.nix

@@ -2,8 +2,6 @@
 let
   cfg = config.services.mysql;
   dataDir = "/data/mysql";
-
-  innodbBufferPoolMB = 128;
 in
 {
   imports = [ ./backup.nix ];
@@ -28,10 +26,6 @@ in
         # Useful for the mysqld prometheus exporter
         userstat = 1;
 
-        # Memory settings
-        innodb_buffer_pool_size = "${toString innodbBufferPoolMB}M";
-        "large-pages" = 1;
-
         # This was needed in order to be able to use all of the old users
         # during migration from knakelibrak to bicep in Sep. 2023
         secure_auth = 0;
@@ -53,10 +47,6 @@ in
     }];
   };
 
-  boot.kernel.hugepages.reservations.mysql = lib.mkIf cfg.enable (
-    builtins.ceil (innodbBufferPoolMB / config.boot.kernel.hugepages.size)
-  );
-
   networking.firewall.allowedTCPPorts = lib.mkIf cfg.enable [ 3306 ];
 
   systemd.tmpfiles.settings."10-mysql".${dataDir}.d = lib.mkIf cfg.enable {

hosts/bicep/services/postgresql/default.nix

@@ -1,8 +1,6 @@
 { config, lib, pkgs, values, ... }:
 let
   cfg = config.services.postgresql;
-
-  sharedBuffersMB = 8192;
 in
 {
   imports = [
@@ -31,7 +29,7 @@ in
       superuser_reserved_connections = 3;
 
       # Memory Settings
-      shared_buffers = "${toString sharedBuffersMB} MB";
+      shared_buffers = "8192 MB";
       work_mem = "32 MB";
       maintenance_work_mem = "420 MB";
       effective_cache_size = "22 GB";
@@ -95,10 +93,6 @@ in
     };
   };
 
-  boot.kernel.hugepages.reservations.postgresql = lib.mkIf cfg.enable (
-    builtins.ceil (sharedBuffersMB / config.boot.kernel.hugepages.size)
-  );
-
   systemd.tmpfiles.settings."10-postgresql"."/data/postgresql".d = lib.mkIf cfg.enable {
     user = config.systemd.services.postgresql.serviceConfig.User;
     group = config.systemd.services.postgresql.serviceConfig.Group;

modules/drumknotty/default.nix

@@ -138,6 +138,15 @@ in
 
         ExecStart =
           let
+            mkRespawningCommand = name: command: pkgs.writeShellScript "drumknotty-${name}-watchdog" ''
+              while true; do
+                ${command}
+                echo
+                echo "${name} exited, restarting in 3s..." >&2
+                sleep 3
+              done
+            '';
+
             screenrc = let
               convertToFile = lines: lib.pipe lines [
                 lib.concatLists
@@ -157,8 +166,7 @@ in
                   config = "/etc/dibbler/dibbler.toml";
                 };
               in lib.optionals cfg.dibbler.enable [
-                "screen -t dibbler ${lib.getExe cfg.dibbler.package} ${dibblerArgs} loop"
-
+                "screen -t dibbler ${mkRespawningCommand "dibbler" "${lib.getExe cfg.dibbler.package} ${dibblerArgs} loop"}"
               ])
 
               (let
@@ -166,7 +174,7 @@ in
                   config = "/etc/worblehat/config.toml";
                 };
               in lib.optionals cfg.worblehat.enable [
-                "screen -t worblehat ${lib.getExe cfg.worblehat.package} ${worblehatArgs} cli"
+                "screen -t worblehat ${mkRespawningCommand "worblehat" "${lib.getExe cfg.worblehat.package} ${worblehatArgs} cli"}"
               ])
 
               [ "select 0" ]

modules/hugepages.nix

@@ -1,38 +0,0 @@
-{ config, lib, ... }:
-let
-  cfg = config.boot.kernel.hugepages;
-in
-{
-  options.boot.kernel.hugepages = {
-    size = lib.mkOption {
-      type = lib.types.enum [ 2 1024 ];
-      default = 2;
-      description = ''
-        Hugepage size in MB.
-
-        You can use this value to calculate the amount of memory you will have available as hugepages.
-      '';
-    };
-
-    reservations = lib.mkOption {
-      type = lib.types.attrsOf lib.types.ints.unsigned;
-      default = { };
-      description = ''
-        Number of hugepages each service wants reserved in vm.nr_hugepages,
-        keyed by service name.
-      '';
-    };
-  };
-
-  config = {
-    boot.kernelParams = let
-      num = {
-        "2" = "2M";
-        "1024" = "1G";
-      }.${toString cfg.size};
-    in [ "hugepagesz=${num}" ];
-
-    boot.kernel.sysctl."vm.nr_hugepages" =
-      lib.foldl' (a: b: a + b) 0 (lib.attrValues cfg.reservations);
-  };
-}