modules/drumknotty: wrap services in infinite loops

base/services/irqbalance.nix

@@ -1,4 +1,22 @@
-{ ... }:
+{ config, pkgs, lib, ... }:
+let
+  cfg = config.services.irqbalance;
+in
 {
   services.irqbalance.enable = true;
-}
+
+  # irqbalance only has meaningful work to do on multi-socket machines, so
+  # skip starting it pointlessly everywhere else.
+  systemd.services.irqbalance.serviceConfig.ExecCondition = let
+    isMultiSocket = pkgs.writeShellApplication {
+      name = "irqbalance-is-multi-socket";
+      runtimeInputs = [ pkgs.coreutils ];
+      text = ''
+        sockets=$(cat /sys/devices/system/cpu/cpu*/topology/physical_package_id | sort -u | wc -l)
+        [ "$sockets" -gt 1 ]
+      '';
+    };
+  in lib.mkIf cfg.enable [
+    (lib.getExe isMultiSocket)
+  ];
+}

hosts/bicep/services/postgresql/default.nix

@@ -14,6 +14,7 @@ in
     extensions = ps: with ps; [ pg_repack ];
     enableTCPIP = true;
 
+    # NOTE: md5 accepts both md5 and scram-sha-256
     authentication = ''
       host all all ${values.ipv4-space} md5
       host all all ${values.ipv6-space} md5
@@ -76,6 +77,15 @@ in
       maintenance_io_concurrency = 100;
       wal_recycle = true;
 
+      # -------------------------------- #
+
+      # Authentication
+      password_encryption = "scram-sha-256";
+
+      # Logging
+      log_connections = "authorization";
+      log_disconnections = true;
+
       # SSL
       ssl = true;
       ssl_cert_file = "/run/credentials/postgresql.service/cert";

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" ]