Powertools Handler

1"""Lambda handler with Powertools Logger, Tracer, Metrics, and Idempotency wired."""
2
3import json
4
5from aws_lambda_powertools import Logger, Metrics, Tracer
6from aws_lambda_powertools.metrics import MetricUnit
7from aws_lambda_powertools.utilities.idempotency import (
8    DynamoDBPersistenceLayer,
9    IdempotencyConfig,
10    idempotent,
11)
12from aws_lambda_powertools.utilities.typing import LambdaContext
13
14logger = Logger()
15tracer = Tracer()
16# Namespace is required (or set POWERTOOLS_METRICS_NAMESPACE); flushing without one raises SchemaValidationError.
17metrics = Metrics(namespace="MyApp")
18persistence = DynamoDBPersistenceLayer(table_name="IdempotencyTable")
19
20# Idempotency key: "body" deduplicates identical payloads.
21config = IdempotencyConfig(event_key_jmespath="body")
22
23
24# Set log_event=True only in non-production environments;
25# events may contain auth tokens, cookies, or PII.
26@logger.inject_lambda_context(log_event=False)
27@tracer.capture_lambda_handler
28@metrics.log_metrics(capture_cold_start_metric=True)
29@idempotent(config=config, persistence_store=persistence)
30def handler(event: dict, context: LambdaContext) -> dict:
31    logger.info("Processing request")
32
33    result = process(event)
34
35    metrics.add_metric(name="RequestsProcessed", unit=MetricUnit.Count, value=1)
36
37    return {
38        "statusCode": 200,
39        "headers": {
40            "Content-Type": "application/json",
41            "Access-Control-Allow-Origin": "https://your-domain.example",  # Replace with your domain
42        },
43        "body": json.dumps(result),
44    }
45
46
47@tracer.capture_method
48def process(event: dict) -> dict:
49    """Replace with your business logic."""
50    return {"message": "success"}