manager: kresctl: 'convert' command added

diff --git a/manager/knot_resolver_manager/cli/cmd/convert.py b/manager/knot_resolver_manager/cli/cmd/convert.py
new file mode 100644 (file)
index 0000000..2253014
--- /dev/null
+++ b/manager/knot_resolver_manager/cli/cmd/convert.py
@@ -0,0 +1,68 @@
+import argparse
+import json
+from typing import Optional, Tuple, Type
+
+import yaml
+
+from knot_resolver_manager.cli.command import Command, CommandArgs, register_command
+from knot_resolver_manager.datamodel import KresConfig
+from knot_resolver_manager.utils.modeling.parsing import ParsedTree, parse_json, parse_yaml
+
+
+def _parse_data(input: str) -> Optional[ParsedTree]:
+    try:
+        return parse_yaml(input)
+    except yaml.YAMLError:
+        print(f"failed to parse input as YAML")
+        try:
+            return parse_json(input)
+        except json.JSONDecodeError:
+            print(f"failed to parse input as JSON")
+            return None
+
+
+@register_command
+class ConvertCommand(Command):
+    def __init__(self, namespace: argparse.Namespace) -> None:
+        super().__init__(namespace)
+        self.input_file: str = namespace.input_file
+        self.output_file: Optional[str] = namespace.output_file
+
+    @staticmethod
+    def register_args_subparser(
+        parser: "argparse._SubParsersAction[argparse.ArgumentParser]",
+    ) -> Tuple[argparse.ArgumentParser, "Type[Command]"]:
+        config = parser.add_parser("convert", help="convert JSON/YAML configuration to Lua script")
+        config.add_argument(
+            "input_file",
+            type=str,
+            help="JSON/YAML configuration input file",
+        )
+
+        config.add_argument("--stdin", help="read new config value on stdin", action="store_true", default=False)
+        config.add_argument(
+            "output_file",
+            type=str,
+            nargs="?",
+            help="optional, output Lua script file",
+            default=None,
+        )
+
+        return config, ConvertCommand
+
+    def run(self, args: CommandArgs) -> None:
+
+        with open(self.input_file, "r") as f:
+            data = f.read()
+
+        parsed = _parse_data(data)
+        if not parsed:
+            return
+
+        lua = KresConfig(parsed).render_lua()
+
+        if self.output_file:
+            with open(self.output_file, "w") as f:
+                f.write(lua)
+        else:
+            print(lua)