From 91dbcb5bdde9fa8b35c5965889a54b135e4d4d7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ale=C5=A1=20Mr=C3=A1zek?= <ales.mrazek@nic.cz>
Date: Tue, 14 Nov 2023 14:04:29 +0100
Subject: [PATCH] kresctl: 'cache-clear' command created

---
 .../cli/cmd/cache_clear.py                    | 79 +++++++++++++++++++
 .../datamodel/cache_schema.py                 |  9 +++
 2 files changed, 88 insertions(+)
 create mode 100644 manager/knot_resolver_manager/cli/cmd/cache_clear.py

diff --git a/manager/knot_resolver_manager/cli/cmd/cache_clear.py b/manager/knot_resolver_manager/cli/cmd/cache_clear.py
new file mode 100644
index 000000000..de4804f7b
--- /dev/null
+++ b/manager/knot_resolver_manager/cli/cmd/cache_clear.py
@@ -0,0 +1,79 @@
+import argparse
+import sys
+from typing import Any, Dict, List, Tuple, Type
+
+from knot_resolver_manager.cli.command import Command, CommandArgs, CompWords, register_command
+from knot_resolver_manager.datamodel.cache_schema import CacheClearRPCSchema
+from knot_resolver_manager.utils.modeling.exceptions import AggregateDataValidationError, DataValidationError
+from knot_resolver_manager.utils.modeling.parsing import DataFormat
+from knot_resolver_manager.utils.requests import request
+
+
+@register_command
+class CacheClearCommand(Command):
+    def __init__(self, namespace: argparse.Namespace) -> None:
+        super().__init__(namespace)
+
+        config_dict: Dict[str, Any] = {"exact-name": namespace.exact_name}
+
+        if hasattr(namespace, "name"):
+            config_dict["name"] = namespace.name
+        if hasattr(namespace, "rr_type"):
+            config_dict["rr-type"] = namespace.rr_type
+        if hasattr(namespace, "chunk_size"):
+            config_dict["chunk-size"] = namespace.chunk_size
+
+        try:
+            self.config = CacheClearRPCSchema(config_dict)
+        except (AggregateDataValidationError, DataValidationError) as e:
+            print(e, file=sys.stderr)
+            sys.exit(1)
+
+    @staticmethod
+    def register_args_subparser(
+        subparser: "argparse._SubParsersAction[argparse.ArgumentParser]",
+    ) -> Tuple[argparse.ArgumentParser, "Type[Command]"]:
+        cache_clear = subparser.add_parser("cache-clear", help="Purge cache records matching specified criteria.")
+        cache_clear.set_defaults(exact_name=True)
+        cache_clear.add_argument(
+            "--exact-name",
+            help="If set, only records with the same name are removed.",
+            action="store_false",
+            dest="exact_name",
+        )
+        cache_clear.add_argument(
+            "--rr-type",
+            help="Optional, you may additionally specify the type to remove, but that is only supported with '--exact-name' flag set.",
+            action="store",
+            type=str,
+        )
+        cache_clear.add_argument(
+            "--chunk-size",
+            help="Optional, the number of records to remove in one round; default: 100."
+            " The purpose is not to block the resolver for long. The resolver repeats the command after one millisecond until all matching data are cleared.",
+            action="store",
+            type=int,
+            default=100,
+        )
+        cache_clear.add_argument(
+            "name",
+            type=str,
+            nargs="?",
+            help="Optional, subtree to purge; if the name isn't provided, whole cache is purged (and any other parameters are disregarded).",
+            default=None,
+        )
+
+        return cache_clear, CacheClearCommand
+
+    @staticmethod
+    def completion(args: List[str], parser: argparse.ArgumentParser) -> CompWords:
+        return {}
+
+    def run(self, args: CommandArgs) -> None:
+        body: str = DataFormat.JSON.dict_dump(self.config.get_unparsed_data())
+        response = request(args.socket, "POST", "cache-clear", body)
+
+        if response.status != 200:
+            print(response, file=sys.stderr)
+            sys.exit(1)
+        print(response)
diff --git a/manager/knot_resolver_manager/datamodel/cache_schema.py b/manager/knot_resolver_manager/datamodel/cache_schema.py
index 4608ee5dd..580a031d0 100644
--- a/manager/knot_resolver_manager/datamodel/cache_schema.py
+++ b/manager/knot_resolver_manager/datamodel/cache_schema.py
@@ -4,10 +4,12 @@
 
 from knot_resolver_manager.datamodel.types import (
     Dir,
+    DNSRecordTypeEnum,
     DomainName,
     EscapedStr,
     File,
     IntNonNegative,
+    IntPositive,
     Percent,
     SizeUnit,
     TimeUnit,
@@ -16,6 +18,13 @@
 from knot_resolver_manager.utils.modeling.base_schema import lazy_default
 
 
+class CacheClearRPCSchema(ConfigSchema):
+    name: Optional[DomainName] = None
+    exact_name: bool = False
+    rr_type: Optional[DNSRecordTypeEnum] = None
+    chunk_size: IntPositive = IntPositive(100)
+
+
 class PrefillSchema(ConfigSchema):
     """
     Prefill the cache periodically by importing zone data obtained over HTTP.