users/services: s6: push bundle dependencies down onto the actual atomic services

modules/users/default.nix

@@ -134,17 +134,6 @@ let
       };
     };
   };
-  defaultUserOptions = with lib; {
-    options = userOptions.options // {
-      services = mkOption {
-        # map to listOf attrs so that we can pass through
-        # w/o worrying about merging at this layer (TODO: this is probably not necessary with s6)
-        type = types.attrsOf (types.coercedTo types.attrs (a: [ a ]) (types.listOf types.attrs));
-        default = {};
-        inherit (userOptions.options.services) description;
-      };
-    };
-  };
   userModule = let
     nixConfig = config;
   in with lib; types.submodule ({ name, config, ... }: {
@@ -201,6 +190,18 @@ let
             set +a
           done
         '';
+
+        services."default" = {
+          description = "service (bundle) which is started by default upon login";
+        };
+        services."graphical-session" = {
+          description = "service (bundle) which is started upon successful graphical login";
+          # partOf = [ "default" ];  #< leave it to the DEs to set this
+        };
+        services."sound" = {
+          description = "service (bundle) which represents functional sound input/output when active";
+          partOf = [ "default" ];
+        };
       }
     ];
   });
@@ -241,7 +242,7 @@ in
     };
 
     sane.user = mkOption {
-      type = types.nullOr (types.submodule defaultUserOptions);
+      type = types.nullOr (types.submodule userOptions);
       default = null;
       description = ''
         options to pass down to the default user

modules/users/s6-rc.nix

@@ -94,6 +94,7 @@ let
           exec ${check}
         '';
       };
+      # N.B.: if this service is a bundle, then dependencies.d is ignored
       "dependencies.d".dir = lib.genAttrs
         depends
         (dep: { text = ""; })
@@ -168,44 +169,29 @@ let
     })
     services
   ;
-
-  # in the systemd service management, these targets are implicitly defined and used
-  # to accomplish something like run-levels, or service groups.
-  # map them onto s6 "bundles". their contents are determined via finding every other service which declares itself to be `partOf` this one.
-  implicitServices = {
-    "default" = {
-      command = null;
-      check = null;
-      cleanupCommand = null;
-      depends = [];
-      dependencyOf = [];
-      partOf = [];
-      readiness.waitCommand = null;
-    };
-    "graphical-session" = {
-      command = null;
-      check = null;
-      cleanupCommand = null;
-      depends = [];
-      dependencyOf = [];
-      partOf = [];
-      readiness.waitCommand = null;
-    };
-    "sound" = {
-      command = null;
-      check = null;
-      cleanupCommand = null;
-      depends = [];
-      dependencyOf = [];
-      partOf = [ "default" ];
-      readiness.waitCommand = null;
-    };
-  };
+  # return a list of bundles (AttrSets) which contain this service
+  containedBy = services: name: lib.filter (svc: lib.elem name svc.contents) services;
+  # for each bundle to which this service belongs, add that bundle's dependencies as direct dependencies of this service.
+  # this is to overcome that s6 doesn't support bundles having dependencies.
+  pushDownDependencies = services: builtins.map
+    (svc: svc // {
+      depends = lib.unique (
+        svc.depends ++ lib.concatMap
+          (bundle: bundle.depends)
+          (containedBy services svc.name)
+      );
+    })
+    services
+  ;
 in
 {
   options.sane.users = with lib; mkOption {
     type = types.attrsOf (types.submodule ({ config, ...}: let
-      sources = genServices (s6SvcsFromConfigServices (implicitServices // config.services));
+      sources = genServices (
+        lib.converge pushDownDependencies (
+          s6SvcsFromConfigServices config.services
+        )
+      );
     in {
       fs.".config/s6/sources".symlink.target = sources;
       # N.B.: `compiled` needs to be writable (for locks -- maybe i can use symlinks to dodge this someday),