Merge pull request 'exports: rename special args' (#4765) from exports-1 into main

Reviewed-on: https://git.clan.lol/clan/clan-core/pulls/4765

lib/modules/inventory/distributed-service/all-services-wrapper.nix

@@ -32,7 +32,7 @@ in
               { name, ... }:
               {
                 _module.args._ctx = [ name ];
-                _module.args.exports' = config.exports;
+                _module.args.exports = config.exports;
                 _module.args.directory = directory;
 
               }

lib/modules/inventory/distributed-service/service-module.nix

@@ -3,6 +3,7 @@
   config,
   _ctx,
   directory,
+  exports,
   ...
 }:
 let
@@ -464,7 +465,7 @@ in
                           roles = applySettings instanceName config.instances.${instanceName};
                         in
                         {
-                          inherit instanceName roles;
+                          inherit instanceName roles exports;
                           machine = {
                             name = machineName;
                             roles = lib.attrNames (lib.filterAttrs (_n: v: v.machines ? ${machineName}) roles);
@@ -608,6 +609,7 @@ in
                 in
                 uniqueStrings (collectRoles machineScope.instances);
             };
+            inherit exports;
             inherit (machineScope) instances;
 
             # There are no machine settings.
@@ -633,14 +635,23 @@ in
     exports = mkOption {
       description = ''
         This services exports.
-        Gets merged with all other services exports
+        Gets merged with all other services exports.
 
-        Final value (merged and evaluated with other services) available as `exports'` in the arguments of this module.
+        Exports are used to share and expose information between instances.
+
+        Define exports in the [`perInstance`](#perInstance) or [`perMachine`](#perMachine) scope.
+
+        Accessing the exports:
 
         ```nix
-        { exports', ... }: {
+        { exports, ... }: {
           _class = "clan.service";
+
           # ...
+          roles.peer.perInstance = { exports, ...}: { ...};
+
+          # ...
+          perMachine = { exports, ...}: { ...};
         }
         ```
       '';

lib/modules/inventory/distributed-service/tests/exports.nix

@@ -24,7 +24,7 @@ let
     machines.sara = { };
     # A module that adds exports perMachine
     modules.A =
-      { exports', ... }:
+      { exports, ... }:
       {
         manifest.name = "A";
         roles.peer.perInstance =
@@ -32,10 +32,10 @@ let
           {
             # Cross reference a perMachine exports
             exports.vars.generators."${machine.name}-network-ip".script =
-              "A:" + exports'.machines.${machine.name}.vars.generators.key.script;
+              "A:" + exports.machines.${machine.name}.vars.generators.key.script;
             # Cross reference a perInstance exports from a different service
             exports.vars.generators."${machine.name}-full-hostname".script =
-              "A:" + exports'.instances."B-1".vars.generators.hostname.script;
+              "A:" + exports.instances."B-1".vars.generators.hostname.script;
           };
         roles.server = { };
         perMachine =