Merge pull request #298983 from illustris/mysql

nixos/systemd-lib: fix restart/reloadTriggers when passing paths

nixos/doc/manual/release-notes/rl-2405.section.md

···
 
 - Ada packages (libraries and tools) have been moved into the `gnatPackages` scope. `gnatPackages` uses the default GNAT compiler, `gnat12Packages` and `gnat13Packages` use the respective matching compiler version.
 
+- Paths provided as `restartTriggers` and `reloadTriggers` for systemd units will now be copied into the nix store to make the behavior consistent.
+  Previously, `restartTriggers = [ ./config.txt ]`, if defined in a flake, would trigger a restart when any part of the flake changed; and if not defined in a flake, would never trigger a restart even if the contents of `config.txt` changed.
+
 - `spark2014` has been renamed to `gnatprove`. A version of `gnatprove` matching different GNAT versions is available from the different `gnatPackages` sets.
 
 - `services.resolved.fallbackDns` can now be used to disable the upstream fallback servers entirely by setting it to an empty list. To get the previous behaviour of the upstream defaults set it to null, the new default, instead.

nixos/lib/systemd-lib.nix

···
     elem
     filter
     filterAttrs
+    flatten
     flip
     head
     isInt
     isList
+    isPath
     length
     makeBinPath
     makeSearchPathOutput
···
     optional
     optionalAttrs
     optionalString
+    pipe
     range
     replaceStrings
     reverseList
···
         // optionalAttrs (config.requisite != [])
           { Requisite = toString config.requisite; }
         // optionalAttrs (config ? restartTriggers && config.restartTriggers != [])
-          { X-Restart-Triggers = "${pkgs.writeText "X-Restart-Triggers-${name}" (toString config.restartTriggers)}"; }
+          { X-Restart-Triggers = "${pkgs.writeText "X-Restart-Triggers-${name}" (pipe config.restartTriggers [
+              flatten
+              (map (x: if isPath x then "${x}" else x))
+              toString
+            ])}"; }
         // optionalAttrs (config ? reloadTriggers && config.reloadTriggers != [])
-          { X-Reload-Triggers = "${pkgs.writeText "X-Reload-Triggers-${name}" (toString config.reloadTriggers)}"; }
+          { X-Reload-Triggers = "${pkgs.writeText "X-Reload-Triggers-${name}" (pipe config.reloadTriggers [
+              flatten
+              (map (x: if isPath x then "${x}" else x))
+              toString
+            ])}"; }
         // optionalAttrs (config.description != "") {
           Description = config.description; }
         // optionalAttrs (config.documentation != []) {