implement sample console notifier

examples/runbook/hello_world.yml

@@ -5,6 +5,8 @@ environment:
   environments:
     - nodes:
         - type: local
+notifier:
+  - type: console
 testcase:
   - criteria:
       area: demo

lisa/notifiers/console.py

@@ -0,0 +1,39 @@
+import logging
+from dataclasses import dataclass
+from typing import List, Type, cast
+
+from dataclasses_json import LetterCase, dataclass_json  # type: ignore
+
+from lisa import notifier, schema
+from lisa.testsuite import TestResultMessage
+
+
+@dataclass_json(letter_case=LetterCase.CAMEL)
+@dataclass
+class ConsoleSchema(schema.TypedSchema):
+    log_level: str = logging.getLevelName(logging.DEBUG)
+
+
+class Console(notifier.Notifier):
+    """
+    It's a sample notifier, output subscribed message to console.
+    It can be used to troubleshooting what kind of message received.
+    """
+
+    @classmethod
+    def type_name(cls) -> str:
+        return "console"
+
+    @classmethod
+    def type_schema(cls) -> Type[schema.TypedSchema]:
+        return ConsoleSchema
+
+    def _received_message(self, message: notifier.MessageBase) -> None:
+        runbook = cast(ConsoleSchema, self._runbook)
+        self._log.log(
+            getattr(logging, runbook.log_level),
+            f"received message [{message.type}]: {message}",
+        )
+
+    def _subscribed_message_type(self) -> List[Type[notifier.MessageBase]]:
+        return [TestResultMessage]