Inventory: implement borgbackup

inventory/default.nix

@@ -0,0 +1,89 @@
+{ inputs, self, ... }:
+let
+  clan-core = self;
+  system = "x86_64-linux";
+  pkgs = clan-core.inputs.nixpkgs.legacyPackages.${system};
+
+  # syncthing_inventory = builtins.fromJSON (builtins.readFile ./src/tests/syncthing.json);
+  syncthing_inventory = builtins.fromJSON (builtins.readFile ./src/tests/borgbackup.json);
+
+  machines = machinesFromInventory {
+    inherit clan-core;
+    lib = pkgs.lib;
+  } syncthing_inventory;
+
+  /*
+    Returns a NixOS configuration for every machine in the inventory.
+
+    machinesFromInventory :: Inventory -> { ${machine_name} :: NixOSConfiguration }
+  */
+  machinesFromInventory =
+    { lib, clan-core, ... }:
+    inventory:
+    # For every machine in the inventory, build a NixOS configuration
+    # For each machine generate config, forEach service, if the machine is used.
+    builtins.mapAttrs (
+      machine_name: _:
+      builtins.foldl' (
+        acc: service_name:
+        let
+          service_config = inventory.services.${service_name};
+          isInService = builtins.elem machine_name (builtins.attrNames service_config.machineConfig);
+
+          machine_service_config = (service_config.machineConfig.${machine_name} or { }).config or { };
+          global_config = inventory.services.${service_name}.config;
+          module_name = inventory.services.${service_name}.module;
+        in
+        # Possible roles: "server", "client", "peer"
+        if
+          builtins.trace ''
+            isInService ${builtins.toJSON isInService},
+            ${builtins.toJSON machine_name} ${builtins.toJSON (builtins.attrNames service_config.machineConfig)}
+          '' isInService
+        then
+          acc
+          ++ [
+            {
+              imports = [ clan-core.clanModules.${module_name} ];
+              config.clan.${module_name} = lib.mkMerge [
+                global_config
+                machine_service_config
+              ];
+            }
+            {
+              config.clan.${module_name} = {
+                # TODO: filter, show only the roles that are needed by the machine
+                roles = builtins.mapAttrs (_m: c: c.roles) service_config.machineConfig;
+              };
+            }
+          ]
+        else
+          acc
+      ) [ ] (builtins.attrNames inventory.services)
+    ) inventory.machines;
+in
+{
+  clan = clan-core.lib.buildClan {
+    meta.name = "vis clans";
+    # Should usually point to the directory of flake.nix
+    directory = self;
+
+    machines = {
+      "vi_machine" = {
+        imports = machines.vi_machine;
+      };
+      "vyr_machine" = {
+        imports = machines.vyr_machine;
+      };
+      "camina_machine" = {
+        imports = machines.camina_machine;
+      };
+    };
+  };
+  intern = machines;
+  # inherit (clan) nixosConfigurations clanInternals;
+  # add the Clan cli tool to the dev shell
+  devShells.${system}.default = pkgs.mkShell {
+    packages = [ clan-core.packages.${system}.clan-cli ];
+  };
+}