Inventory: simplify build-clan interface

clanModules/borgbackup/default.nix

@@ -27,8 +27,50 @@ let
       exit 1
     fi
   '';
+
+  # Each .nix file in the roles directory is a role
+  # TODO: Helper function to set available roles within module meta.
+  # roles = lib.pipe ./roles [
+  #   (p: if builtins.pathExists p then p else throw "Role directory does not exist")
+  #   builtins.readDir
+  #   (lib.filterAttrs (_n: v: v == "regular"))
+  #   lib.attrNames
+  #   (map (fileName: lib.removeSuffix ".nix" fileName))
+  # ];
+
+  # TODO: make this an interface of every module
+  # Maybe load from readme.md
+  metaInfoOption = lib.mkOption {
+    readOnly = true;
+    default = {
+      description = "A category for the service. This is used to group services in the clan ui";
+    };
+    type = lib.types.submodule {
+      options = {
+        description = lib.mkOption {
+          description = "A category for the service. This is used to group services in the clan ui";
+          type = lib.types.str;
+        };
+        # icon = lib.mkOption {
+        #   description = "A category for the service. This is used to group services in the clan ui";
+        #   type = lib.types.str;
+        # };
+        # screenshots = lib.mkOption {
+        #   description = "A category for the service. This is used to group services in the clan ui";
+        #   type = lib.types.str;
+        # };
+        # category = lib.mkOption {
+        #   description = "A category for the service. This is used to group services in the clan ui";
+        #   type = lib.types.enum ["backup" "network"];
+        # };
+      };
+    };
+  };
 in
 {
+
+  options.clan.borgbackup.meta = metaInfoOption;
+
   options.clan.borgbackup.destinations = lib.mkOption {
     type = lib.types.attrsOf (
       lib.types.submodule (
@@ -63,6 +105,11 @@ in
   };
 
   imports = [
+    {
+      config.clan.borgbackup.meta = {
+        description = "backup";
+      };
+    }
     (lib.mkRemovedOptionModule [
       "clan"
       "borgbackup"
@@ -76,7 +123,7 @@ in
       lib.nameValuePair "borgbackup-job-${dest.name}" {
         # since borgbackup mounts the system read-only, we need to run in a ExecStartPre script, so we can generate additional files.
         serviceConfig.ExecStartPre = [
-          (''+${pkgs.writeShellScript "borgbackup-job-${dest.name}-pre-backup-commands" preBackupScript}'')
+          ''+${pkgs.writeShellScript "borgbackup-job-${dest.name}-pre-backup-commands" preBackupScript}''
         ];
       }
     ) cfg.destinations;

inventory/default.nix

@@ -4,23 +4,19 @@ let
 in
 {
   clan = clan-core.lib.buildClan {
-
     meta.name = "kenjis clan";
     # Should usually point to the directory of flake.nix
     directory = self;
 
-    # service config
-    # Useful alias: "inventory.services.borgbackup.default"
-    services = {
-      borgbackup = {
-        roles.server.machines = [ "vyr_machine" ];
-        roles.client.tags = [ "laptop" ];
+    inventory = {
+      services = {
+        borgbackup.instance_1 = {
+          roles.server.machines = [ "vyr_machine" ];
+          roles.client.tags = [ "laptop" ];
+        };
       };
     };
 
-    # merged with
-    inventory = builtins.fromJSON (builtins.readFile ./src/tests/borgbackup.json);
-
     # merged with
     machines = {
       "vyr_machine" = { };

lib/build-clan/default.nix

@@ -15,15 +15,6 @@
   # A map from arch to pkgs, if specified this nixpkgs will be only imported once for each system.
   # This improves performance, but all nipxkgs.* options will be ignored.
   pkgsForSystem ? (_system: null),
-  /*
-    Distributed services configuration.
-
-    This configures a default instance in the inventory with the name "default".
-
-    If you need multiple instances of a service configure them via:
-    inventory.services.[serviceName].[instanceName] = ...
-  */
-  services ? { },
   /*
     Low level inventory configuration.
     Overrides the services configuration.
@@ -44,15 +35,15 @@ let
       modules = [
         ./interface.nix
         { inherit meta; }
-        # Default instances configured via 'services'
-        {
-          services = lib.mapAttrs (_name: value: {
-            default = value // {
-              meta.name = lib.mkDefault _name;
-            };
-          }) services;
-        }
-        # The inventory overrides
+        (
+          if
+            builtins.pathExists "${directory}/inventory.json"
+          # Is recursively applied. Any explicit nix will override.
+          then
+            lib.mkDefault (builtins.fromJSON (builtins.readFile "${directory}/inventory.json"))
+          else
+            { }
+        )
         inventory
         # Machines explicitly configured via 'machines' argument
         {
@@ -79,13 +70,17 @@ let
             }
           ) machines;
         }
-        # Machines that exist in the machines directory
-        { machines = lib.mapAttrs (name: _: { inherit name; }) machinesDirs; }
+
+        # Deprecated interface
+        (if clanName != null then { meta.name = clanName; } else { })
+        (if clanIcon != null then { meta.icon = clanIcon; } else { })
       ];
     }).config;
 
   buildInventory = import ./inventory.nix { inherit lib clan-core; };
 
+  # map from machine name to service configuration
+  # { ${machineName} :: Config }
   serviceConfigs = buildInventory mergedInventory;
 
   deprecationWarnings = [
@@ -95,62 +90,6 @@ let
     (lib.warnIf (clanIcon != null) "clanIcon is deprecated, please use meta.icon instead" null)
   ];
 
-  machinesDirs = lib.optionalAttrs (builtins.pathExists "${directory}/machines") (
-    builtins.readDir (directory + /machines)
-  );
-
-  mergedMeta =
-    let
-      metaFromFile =
-        if (builtins.pathExists "${directory}/clan/meta.json") then
-          let
-            settings = builtins.fromJSON (builtins.readFile "${directory}/clan/meta.json");
-          in
-          settings
-        else
-          { };
-      legacyMeta = lib.filterAttrs (_: v: v != null) {
-        name = clanName;
-        icon = clanIcon;
-      };
-      optionsMeta = lib.filterAttrs (_: v: v != null) meta;
-
-      warnings =
-        builtins.map (
-          name:
-          if
-            metaFromFile.${name} or null != optionsMeta.${name} or null && optionsMeta.${name} or null != null
-          then
-            lib.warn "meta.${name} is set in different places. (exlicit option meta.${name} overrides ${directory}/clan/meta.json)" null
-          else
-            null
-        ) (builtins.attrNames metaFromFile)
-        ++ [ (if (res.name or null == null) then (throw "meta.name should be set") else null) ];
-      res = metaFromFile // legacyMeta // optionsMeta;
-    in
-    # Print out warnings before returning the merged result
-    builtins.deepSeq warnings res;
-
-  machineSettings =
-    machineName:
-    # CLAN_MACHINE_SETTINGS_FILE allows to override the settings file temporarily
-    # This is useful for doing a dry-run before writing changes into the settings.json
-    # Using CLAN_MACHINE_SETTINGS_FILE requires passing --impure to nix eval
-    if builtins.getEnv "CLAN_MACHINE_SETTINGS_FILE" != "" then
-      builtins.fromJSON (builtins.readFile (builtins.getEnv "CLAN_MACHINE_SETTINGS_FILE"))
-    else
-      lib.optionalAttrs (builtins.pathExists "${directory}/machines/${machineName}/settings.json") (
-        builtins.fromJSON (builtins.readFile (directory + /machines/${machineName}/settings.json))
-      );
-
-  # Read additional imports specified via a config option in settings.json
-  # This is not an infinite recursion, because the imports are discovered here
-  #   before calling evalModules.
-  # It is still useful to have the imports as an option, as this allows for type
-  #   checking and easy integration with the config frontend(s)
-  machineImports =
-    machineSettings: map (module: clan-core.clanModules.${module}) (machineSettings.clanImports or [ ]);
-
   # TODO: remove default system once we have a hardware-config mechanism
   nixosConfiguration =
     {
@@ -160,47 +99,41 @@ let
       extraConfig ? { },
     }:
     nixpkgs.lib.nixosSystem {
-      modules =
-        let
-          settings = machineSettings name;
-        in
-        (machineImports settings)
-        ++ [
-          settings
-          clan-core.nixosModules.clanCore
-          extraConfig
-          (machines.${name} or { })
-          # Inherit the inventory assertions ?
-          { inherit (mergedInventory) assertions; }
-          { imports = serviceConfigs.${name} or { }; }
-          (
-            {
-              # Settings
-              clan.core.clanDir = directory;
-              # Inherited from clan wide settings
-              clan.core.clanName = meta.name or clanName;
-              clan.core.clanIcon = meta.icon or clanIcon;
+      modules = [
+        clan-core.nixosModules.clanCore
+        extraConfig
+        (machines.${name} or { })
+        # Inherit the inventory assertions ?
+        { inherit (mergedInventory) assertions; }
+        { imports = serviceConfigs.${name} or { }; }
+        (
+          {
+            # Settings
+            clan.core.clanDir = directory;
+            # Inherited from clan wide settings
+            clan.core.clanName = meta.name or clanName;
+            clan.core.clanIcon = meta.icon or clanIcon;
 
-              # Machine specific settings
-              clan.core.machineName = name;
-              networking.hostName = lib.mkDefault name;
-              nixpkgs.hostPlatform = lib.mkDefault system;
+            # Machine specific settings
+            clan.core.machineName = name;
+            networking.hostName = lib.mkDefault name;
+            nixpkgs.hostPlatform = lib.mkDefault system;
 
-              # speeds up nix commands by using the nixpkgs from the host system (especially useful in VMs)
-              nix.registry.nixpkgs.to = {
-                type = "path";
-                path = lib.mkDefault nixpkgs;
-              };
-            }
-            // lib.optionalAttrs (pkgs != null) { nixpkgs.pkgs = lib.mkForce pkgs; }
-          )
-        ];
+            # speeds up nix commands by using the nixpkgs from the host system (especially useful in VMs)
+            nix.registry.nixpkgs.to = {
+              type = "path";
+              path = lib.mkDefault nixpkgs;
+            };
+          }
+          // lib.optionalAttrs (pkgs != null) { nixpkgs.pkgs = lib.mkForce pkgs; }
+        )
+      ];
       specialArgs = {
         inherit clan-core;
       } // specialArgs;
     };
 
-  allMachines = machinesDirs // machines;
+  allMachines = mergedInventory.machines or { };
 
   supportedSystems = [
     "x86_64-linux"
@@ -252,11 +185,11 @@ builtins.deepSeq deprecationWarnings {
   inherit nixosConfigurations;
 
   clanInternals = {
-    # Evaluated clan meta
-    # Merged /clan/meta.json with overrides from buildClan
-    meta = mergedMeta;
+    meta = mergedInventory.meta;
     inventory = mergedInventory;
 
+    invFile = "${directory}/inventory.json";
+
     # machine specifics
     machines = configsPerSystem;
     machinesFunc = configsFuncPerSystem;