validator: hostname init

pkgs/clan-cli/clan_lib/validator/hostname.py

@@ -0,0 +1,30 @@
+import re
+
+from clan_lib.errors import ClanError
+
+
+def hostname(host: str) -> str:
+    """
+    Validates a hostname according to the expected format in NixOS.
+
+    Usage Example
+
+    @dataclass
+    class Clan:
+        name: str
+
+        def validate(self) -> None:
+            from clan_lib.validator.hostname import hostname
+            try:
+                hostname(self.name)
+            except ValueError as e:
+                raise ClanError(str(e), location="name")
+    """
+
+    # TODO: Generate from nix schema
+    hostname_regex = r"^(?!-)[A-Za-z0-9-]{1,63}(?<!-)$"
+    if not re.fullmatch(hostname_regex, host):
+        msg = "Machine name must be a valid hostname"
+        raise ClanError(msg, location="Create Machine")
+
+    return host