docs: Add information about nixos-rebuild

docs/mkdocs.yml

@@ -69,6 +69,7 @@ nav:
       - Zerotier VPN: guides/mesh-vpn.md
       - How to disable Secure Boot: guides/secure-boot.md
       - Flake-parts: guides/flake-parts.md
+      - Nixos-rebuild: guides/nixos-rebuild.md
       - macOS: guides/macos.md
       - Contributing:
           - Contributing: guides/contributing/CONTRIBUTING.md

docs/site/guides/nixos-rebuild.md

@@ -0,0 +1,68 @@
+# Can I still use `nixos-rebuild`?
+
+**Yes, you can still use `nixos-rebuild` with clan!**
+
+Clan is built on top of standard `NixOS` and uses `nixos-rebuild` internally.
+However, there are important considerations when using `nixos-rebuild` directly instead of `clan machines update`.
+
+## Important Considerations
+
+!!! warning "Vars Must Be Uploaded First"
+    If your configuration uses clan vars, failing to run `clan vars upload` before `nixos-rebuild` will result in missing secrets and potentially broken services.
+
+!!! info "Build Host Configuration"
+    Clan automatically handles build host configuration based on your machine settings.
+    When using `nixos-rebuild` manually, you need to specify `--build-host` and `--target-host` options yourself.
+
+## How Clan Uses nixos-rebuild
+
+Clan doesn't replace `nixos-rebuild` - it enhances it. When you run `clan machines update`, clan:
+
+1. Generates and uploads secrets/variables (if any)
+2. Uploads the flake source to the target/build host (if needed)
+3. Runs `nixos-rebuild switch` with the appropriate options
+4. Handles remote building and deployment automatically
+
+Under the hood, clan executes commands like:
+
+```bash
+nixos-rebuild switch --fast --build-host builtHost --flake /path/to/flake#machine-name
+```
+
+## When You Need `clan vars upload`
+
+If your clan configuration uses **variables (vars)** - generated secrets, keys, or configuration values - you **must** run `clan vars upload` before using `nixos-rebuild` directly.
+
+### Systems that use vars include:
+
+- Any `clanModules` with generated secrets (zerotier, borgbackup, etc.)
+- Custom generators that create passwords or keys
+- Services that need shared configuration values
+
+### Systems that don't need vars:
+
+- Basic NixOS configurations without clan-specific services
+- Static configurations with hardcoded values
+- Systems using only traditional NixOS secrets management
+
+## Manual nixos-rebuild Workflow
+
+When you want to use `nixos-rebuild` directly:
+
+### Step 1: Upload vars (if needed)
+
+```bash
+# Upload secret vars to the target machine
+clan vars upload my-machine
+```
+
+### Step 2: Run nixos-rebuild
+
+```bash
+nixos-rebuild switch --flake .#my-machine --target-host root@target-ip --build-host local
+```
+
+## Related Documentation
+
+- [Update Your Machines](getting-started/update.md) - Using clan's update command
+- [Variables (Vars)](../reference/clan-core/vars.md) - Understanding the vars system

pkgs/clan-cli/clan_cli/facts/secret_modules/password_store.py

@@ -77,9 +77,7 @@ class SecretStore(SecretStoreBase):
                 check=False,
             ).stdout.strip(),
         )
-        for symlink in Path(password_store).glob(f"machines/{self.machine.name}/**/*"):
-            if symlink.is_symlink():
-                hashes.append(
+        hashes.extend(
             subprocess.run(
                 nix_shell(
                     ["git"],
@@ -95,7 +93,11 @@ class SecretStore(SecretStoreBase):
                 ),
                 stdout=subprocess.PIPE,
                 check=False,
-                    ).stdout.strip(),
+            ).stdout.strip()
+            for symlink in Path(password_store).glob(
+                f"machines/{self.machine.name}/**/*",
+            )
+            if symlink.is_symlink()
         )
 
         # we sort the hashes to make sure that the order is always the same

pkgs/clan-cli/clan_cli/secrets/folders.py

@@ -23,13 +23,9 @@ sops_groups_folder = gen_sops_subfolder("groups")
 
 
 def list_objects(path: Path, is_valid: Callable[[str], bool]) -> list[str]:
-    objs: list[str] = []
     if not path.exists():
-        return objs
-    for f in path.iterdir():
-        if is_valid(f.name):
-            objs.append(f.name)
-    return objs
+        return []
+    return [f.name for f in path.iterdir() if is_valid(f.name)]
 
 
 def remove_object(path: Path, name: str) -> list[Path]:

pkgs/clan-cli/clan_cli/secrets/groups.py

@@ -64,17 +64,17 @@ def list_groups(flake_dir: Path) -> list[Group]:
         if not group_folder.is_dir():
             continue
         machines_path = machines_folder(flake_dir, group.name)
-        machines = []
-        if machines_path.is_dir():
-            for f in machines_path.iterdir():
-                if validate_hostname(f.name):
-                    machines.append(f.name)
+        machines = (
+            [f.name for f in machines_path.iterdir() if validate_hostname(f.name)]
+            if machines_path.is_dir()
+            else []
+        )
         users_path = users_folder(flake_dir, group.name)
-        users = []
-        if users_path.is_dir():
-            for f in users_path.iterdir():
-                if VALID_USER_NAME.match(f.name):
-                    users.append(f.name)
+        users = (
+            [f.name for f in users_path.iterdir() if VALID_USER_NAME.match(f.name)]
+            if users_path.is_dir()
+            else []
+        )
         groups.append(Group(flake_dir, group.name, machines, users))
     return groups
 
@@ -270,11 +270,11 @@ def get_groups(flake_dir: Path, what: str, name: str) -> list[str]:
     if not groups_dir.exists():
         return []
 
-    groups = []
-    for group in groups_dir.iterdir():
-        if group.is_dir() and (group / what / name).is_symlink():
-            groups.append(group.name)
-    return groups
+    return [
+        group.name
+        for group in groups_dir.iterdir()
+        if group.is_dir() and (group / what / name).is_symlink()
+    ]
 
 
 def add_secret_command(args: argparse.Namespace) -> None:

pkgs/clan-cli/clan_cli/secrets/secrets.py

@@ -41,7 +41,7 @@ log = logging.getLogger(__name__)
 
 
 def list_generators_secrets(generators_path: Path) -> list[Path]:
-    paths = []
+    paths: list[Path] = []
     for generator_path in generators_path.iterdir():
         if not generator_path.is_dir():
             continue
@@ -49,11 +49,13 @@ def list_generators_secrets(generators_path: Path) -> list[Path]:
         def validate(generator_path: Path, name: str) -> bool:
             return has_secret(generator_path / name)
 
+        paths.extend(
+            generator_path / obj
             for obj in list_objects(
                 generator_path,
                 functools.partial(validate, generator_path),
-        ):
-            paths.append(generator_path / obj)
+            )
+        )
     return paths
 
 

pkgs/clan-cli/clan_cli/ssh/deploy_info.py

@@ -58,10 +58,7 @@ def ssh_command(args: argparse.Namespace) -> None:
             raise ClanError(msg)
 
         # Convert ssh_option list to dictionary
-        ssh_options = {}
-        if args.ssh_option:
-            for name, value in args.ssh_option:
-                ssh_options[name] = value
+        ssh_options = dict(args.ssh_option) if args.ssh_option else {}
 
         remote = remote.override(
             host_key_check=args.host_key_check,

pkgs/clan-cli/clan_cli/tests/test_api_dataclass_compat.py

@@ -63,7 +63,7 @@ def find_dataclasses_in_directory(
                                 and isinstance(deco.func, ast.Name)
                                 and deco.func.id == "dataclass"
                             ):
-                                dataclass_files.append((file_path, node.name))
+                                dataclass_files.append((file_path, node.name))  # noqa: PERF401
             except (SyntaxError, UnicodeDecodeError) as e:
                 print(f"Error parsing {file_path}: {e}")
 

pkgs/clan-cli/clan_cli/vars/secret_modules/password_store.py

@@ -164,11 +164,12 @@ class SecretStore(StoreBase):
 
         from clan_cli.vars.generator import Generator
 
-        manifest = []
         generators = Generator.get_machine_generators(machine, self.flake)
-        for generator in generators:
-            for file in generator.files:
-                manifest.append(f"{generator.name}/{file.name}".encode())
+        manifest = [
+            f"{generator.name}/{file.name}".encode()
+            for generator in generators
+            for file in generator.files
+        ]
 
         manifest.append(git_hash)
         return b"\n".join(manifest)

pkgs/clan-cli/clan_lib/backups/list.py

@@ -14,7 +14,6 @@ class Backup:
 
 
 def list_provider(machine: Machine, host: Remote, provider: str) -> list[Backup]:
-    results = []
     backup_metadata = machine.select("config.clan.core.backups")
     list_command = backup_metadata["providers"][provider]["list"]
     proc = host.run(
@@ -35,8 +34,11 @@ def list_provider(machine: Machine, host: Remote, provider: str) -> list[Backup]
         msg = f"Failed to parse json output from provider {provider}:\n{proc.stdout}"
         raise ClanError(msg) from e
 
-    for archive in parsed_json:
-        results.append(Backup(name=archive["name"], job_name=archive.get("job_name")))
+    results: list[Backup] = []
+    results.extend(
+        Backup(name=archive["name"], job_name=archive.get("job_name"))
+        for archive in parsed_json
+    )
     return results
 
 

pkgs/clan-cli/clan_lib/flake/flake.py

@@ -444,8 +444,9 @@ class FlakeCacheEntry:
                 if not isinstance(selector.value, list):
                     msg = f"Expected list for SET selector value, got {type(selector.value)}"
                     raise ClanError(msg)
-                for subselector in selector.value:
-                    fetched_indices.append(subselector.value)
+                fetched_indices.extend(
+                    subselector.value for subselector in selector.value
+                )
             # if it's just a str, that is the index
             elif selector.type == SelectorType.STR:
                 if not isinstance(selector.value, str):
@@ -635,9 +636,9 @@ class FlakeCacheEntry:
             keys_to_select: list[str] = []
             # if we want to select all keys, we take all existing sub elements
             if selector.type == SelectorType.ALL:
-                for key in self.value:
-                    if self.value[key].exists:
-                        keys_to_select.append(key)
+                keys_to_select.extend(
+                    key for key in self.value if self.value[key].exists
+                )
 
             # if we want to select a set of keys, we take the keys from the selector
             if selector.type == SelectorType.SET:
@@ -657,9 +658,9 @@ class FlakeCacheEntry:
 
             # if we are a list, return a list
             if self.is_list:
-                result_list: list[Any] = []
-                for index in keys_to_select:
-                    result_list.append(self.value[index].select(selectors[1:]))
+                result_list: list[Any] = [
+                    self.value[index].select(selectors[1:]) for index in keys_to_select
+                ]
                 return result_list
 
             # otherwise return a dict
@@ -681,12 +682,10 @@ class FlakeCacheEntry:
         if selector.type == SelectorType.ALL:
             str_selector = "*"
         elif selector.type == SelectorType.SET:
-            subselectors: list[str] = []
             if not isinstance(selector.value, list):
                 msg = f"Expected list for SET selector value in error handling, got {type(selector.value)}"
                 raise ClanError(msg)
-            for subselector in selector.value:
-                subselectors.append(subselector.value)
+            subselectors = [subselector.value for subselector in selector.value]
             str_selector = "{" + ",".join(subselectors) + "}"
         else:
             if not isinstance(selector.value, str):
@@ -967,9 +966,9 @@ class Flake:
 
         nix_options = self.nix_options[:] if self.nix_options is not None else []
 
-        str_selectors: list[str] = []
-        for selector in selectors:
-            str_selectors.append(selectors_as_json(parse_selector(selector)))
+        str_selectors = [
+            selectors_as_json(parse_selector(selector)) for selector in selectors
+        ]
 
         config = nix_config()
 
@@ -1079,10 +1078,9 @@ class Flake:
         if self.flake_cache_path is None:
             msg = "Flake cache path cannot be None"
             raise ClanError(msg)
-        not_fetched_selectors = []
-        for selector in selectors:
-            if not self._cache.is_cached(selector):
-                not_fetched_selectors.append(selector)
+        not_fetched_selectors = [
+            selector for selector in selectors if not self._cache.is_cached(selector)
+        ]
 
         if not_fetched_selectors:
             self.get_from_nix(not_fetched_selectors)

pkgs/clan-cli/clan_lib/persist/util.py

@@ -133,12 +133,7 @@ def list_difference(all_items: list, filter_items: list) -> list:
 
     """
     # Unmerge the lists
-    res = []
-    for value in all_items:
-        if value not in filter_items:
-            res.append(value)
-
-    return res
+    return [value for value in all_items if value not in filter_items]
 
 
 def find_duplicates(string_list: list[str]) -> list[str]:

pkgs/clan-cli/openapi.py

@@ -105,11 +105,10 @@ def fix_nullables(schema: dict) -> dict:
     if isinstance(schema, dict):
         if "type" in schema and schema["type"] == "null":
             # Convert 'type: null' to 'nullable: true'
-            new_schema = {"nullable": True}
             # Merge any other keys from original schema except type
-            for k, v in schema.items():
-                if k != "type":
-                    new_schema[k] = v
+            new_schema = {"nullable": True} | {
+                k: v for k, v in schema.items() if k != "type"
+            }
             return fix_nullables(new_schema)
 
         # If 'oneOf' present