add lambda request id in logs events

Author: Karthikeyannhs

src/eligibility_signposting_api/app.py

@@ -11,6 +11,7 @@
 from eligibility_signposting_api.common.error_handler import handle_exception
 from eligibility_signposting_api.common.request_validator import validate_request_params
 from eligibility_signposting_api.config.config import config, init_logging
+from eligibility_signposting_api.contextvars_manager import request_id_var
 from eligibility_signposting_api.views import eligibility_blueprint
 
 init_logging()
@@ -25,6 +26,8 @@ def main() -> None:  # pragma: no cover
 
 @validate_request_params()
 def lambda_handler(event: LambdaEvent, context: LambdaContext) -> dict[str, Any]:  # pragma: no cover
+    request_id_var.set(context.aws_request_id)
+
     """Run the Flask app as an AWS Lambda."""
     app = create_app()
     app.debug = config()["log_level"] == logging.DEBUG

src/eligibility_signposting_api/config/config.py

@@ -7,6 +7,7 @@
 from pythonjsonlogger.json import JsonFormatter
 from yarl import URL
 
+from eligibility_signposting_api.contextvars_manager import request_id_var
 from eligibility_signposting_api.repos.campaign_repo import BucketName
 from eligibility_signposting_api.repos.person_repo import TableName
 
@@ -59,9 +60,16 @@ def config() -> dict[str, Any]:
     }
 
 
+class LoggingJsonFormatter(logging.Formatter):
+    def format(self, record: logging.LogRecord) -> str:
+        # Insert request_id from contextvar for every log record
+        record.request_id = request_id_var.get() or "-"
+        return super().format(record)
+
+
 def init_logging(quieten: Sequence[str] = ("asyncio", "botocore", "boto3", "mangum", "urllib3")) -> None:
     log_format = "%(asctime)s %(levelname)-8s %(name)s %(module)s.py:%(funcName)s():%(lineno)d %(message)s"
-    formatter = JsonFormatter(log_format)
+    formatter = LoggingJsonFormatter(log_format)
     handler = logging.StreamHandler()
     handler.setFormatter(formatter)
     logging.root.handlers = []  # Clear any existing handlers

src/eligibility_signposting_api/contextvars_manager.py

@@ -0,0 +1,3 @@
+from contextvars import ContextVar
+
+request_id_var: ContextVar[str | None] = ContextVar("request_id", default=None)