nixos-rebuild-ng: move _get_hostname to Flake

pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/models.py

@@ -63,20 +63,6 @@ class BuildAttr:
         return cls(Path(file or "default.nix"), attr)
 
 
-def _get_hostname(target_host: Remote | None) -> str | None:
-    if target_host:
-        try:
-            return run_wrapper(
-                ["uname", "-n"],
-                capture_output=True,
-                remote=target_host,
-            ).stdout.strip()
-        except (AttributeError, subprocess.CalledProcessError):
-            return None
-    else:
-        return platform.node()
-
-
 @dataclass(frozen=True)
 class Flake:
     path: str
@@ -95,9 +81,7 @@ class Flake:
         m = cls._re.match(flake_str)
         assert m is not None, f"got no matches for {flake_str}"
         attr = m.group("attr")
-        nixos_attr = (
-            f'nixosConfigurations."{attr or _get_hostname(target_host) or "default"}"'
-        )
+        nixos_attr = f'nixosConfigurations."{attr or cls._get_hostname(target_host) or "default"}"'
         path = m.group("path")
         return cls(path, nixos_attr)
 
@@ -126,6 +110,20 @@ class Flake:
         except FileNotFoundError:
             return self.path
 
+    @staticmethod
+    def _get_hostname(target_host: Remote | None) -> str | None:
+        if target_host:
+            try:
+                return run_wrapper(
+                    ["uname", "-n"],
+                    capture_output=True,
+                    remote=target_host,
+                ).stdout.strip()
+            except (AttributeError, subprocess.CalledProcessError):
+                return None
+        else:
+            return platform.node()
+
 
 @dataclass(frozen=True)
 class Generation: