feat(logging): add get_correlation_id

Author: Michael Brewer

aws_lambda_powertools/logging/logger.py

@@ -400,6 +400,16 @@ def set_correlation_id(self, value: Optional[str]):
         else:
             self.append_keys(correlation_id=value)
 
+    def get_correlation_id(self) -> Optional[str]:
+        """Gets the correlation_id in the logging json
+
+        Returns
+        -------
+        str, optional
+            Value for the correlation id
+        """
+        return self.registered_formatter.log_format.get("correlation_id")
+
     @staticmethod
     def _get_log_level(level: Union[str, int, None]) -> Union[str, int]:
         """Returns preferred log level set by the customer in upper case"""

tests/functional/test_logger.py

@@ -474,6 +474,18 @@ def test_logger_set_correlation_id_to_none(lambda_context, stdout, service_name)
     assert "correlation_id" not in log
 
 
+def test_logger_get_correlation_id(lambda_context, stdout, service_name):
+    # GIVEN a logger with a correlation_id set
+    logger = Logger(service=service_name, stream=stdout)
+    logger.set_correlation_id("foo")
+
+    # WHEN calling get_correlation_id
+    correlation_id = logger.get_correlation_id()
+
+    # THEN it should return the correlation_id
+    assert "foo" == correlation_id
+
+
 def test_logger_set_correlation_id_path(lambda_context, stdout, service_name):
     # GIVEN
     logger = Logger(service=service_name, stream=stdout)