clanCore: refactor flake-module.nix into smaller files

nixosModules/clanCore/outputs.nix

@@ -0,0 +1,76 @@
+{ config, lib, pkgs, ... }: {
+  # TODO: factor these out into a separate interface.nix.
+  # Also think about moving these options out of `system.clan`.
+  # Maybe we should not re-use the already polluted confg.system namespace
+  #   and instead have a separate top-level namespace like `clanOutputs`, with
+  #   well defined options marked as `internal = true;`.
+  options.system.clan = lib.mkOption {
+    type = lib.types.submodule {
+      options = {
+        deployment.data = lib.mkOption {
+          type = lib.types.attrs;
+          description = ''
+            the data to be written to the deployment.json file
+          '';
+        };
+        deployment.file = lib.mkOption {
+          type = lib.types.path;
+          description = ''
+            the location of the deployment.json file
+          '';
+        };
+        deploymentAddress = lib.mkOption {
+          type = lib.types.str;
+          description = ''
+            the address of the deployment server
+          '';
+        };
+        secretsUploadDirectory = lib.mkOption {
+          type = lib.types.path;
+          description = ''
+            the directory on the deployment server where secrets are uploaded
+          '';
+        };
+        uploadSecrets = lib.mkOption {
+          type = lib.types.path;
+          description = ''
+            script to upload secrets to the deployment server
+          '';
+          default = "${pkgs.coreutils}/bin/true";
+        };
+        generateSecrets = lib.mkOption {
+          type = lib.types.path;
+          description = ''
+            script to generate secrets
+          '';
+          default = "${pkgs.coreutils}/bin/true";
+        };
+        vm.config = lib.mkOption {
+          type = lib.types.attrs;
+          description = ''
+            the vm config
+          '';
+        };
+        vm.create = lib.mkOption {
+          type = lib.types.path;
+          description = ''
+            json metadata about the vm
+          '';
+        };
+      };
+    };
+    description = ''
+      utility outputs for clan management of this machine
+    '';
+  };
+  # optimization for faster secret generate/upload and machines update
+  config = {
+    system.clan.deployment.data = {
+      inherit (config.system.clan) uploadSecrets generateSecrets;
+      inherit (config.clan.networking) deploymentAddress;
+      inherit (config.clanCore) secretsUploadDirectory;
+    };
+    system.clan.deployment.file = pkgs.writeText "deployment.json" (builtins.toJSON config.system.clan.deployment.data);
+  };
+
+}