123 lines
4.4 KiB
Python
123 lines
4.4 KiB
Python
import json
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import os
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import boto3
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import uuid
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import logging
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from datetime import datetime
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from botocore.exceptions import ClientError
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import time
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import random
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# Logging konfigurieren
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logger = logging.getLogger()
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logger.setLevel(logging.INFO)
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sqs = boto3.client('sqs')
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# Retry-Konfiguration
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MAX_RETRIES = 3
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BASE_BACKOFF = 1 # Sekunden
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def exponential_backoff(attempt):
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"""Exponential Backoff mit Jitter"""
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return BASE_BACKOFF * (2 ** attempt) + random.uniform(0, 1)
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def get_queue_url(domain):
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"""
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Generiert Queue-Namen aus Domain und holt URL.
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Konvention: domain.tld -> domain-tld-queue
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"""
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queue_name = domain.replace('.', '-') + '-queue'
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try:
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response = sqs.get_queue_url(QueueName=queue_name)
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return response['QueueUrl']
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except ClientError as e:
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if e.response['Error']['Code'] == 'AWS.SimpleQueueService.NonExistentQueue':
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logger.error(f"Queue nicht gefunden für Domain: {domain}")
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raise ValueError(f"Keine Queue für Domain {domain}")
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else:
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raise
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def lambda_handler(event, context):
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"""
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Nimmt SES Event entgegen, extrahiert Domain dynamisch,
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verpackt Metadaten als 'Fake SNS' und sendet an die domain-spezifische SQS.
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Mit integrierter Retry-Logik für SQS-Send.
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"""
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try:
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records = event.get('Records', [])
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logger.info(f"Received event with {len(records)} records.")
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for record in records:
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ses_data = record.get('ses', {})
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if not ses_data:
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logger.warning(f"Invalid SES event: Missing 'ses' in record: {record}")
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continue
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mail = ses_data.get('mail', {})
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receipt = ses_data.get('receipt', {})
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# Domain extrahieren (aus erstem Recipient)
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recipients = receipt.get('recipients', []) or mail.get('destination', [])
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if not recipients:
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logger.warning("No recipients in event - skipping")
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continue
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first_recipient = recipients[0]
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domain = first_recipient.split('@')[-1].lower()
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if not domain:
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logger.error("Could not extract domain from recipient")
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continue
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# Wichtige Metadaten loggen
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msg_id = mail.get('messageId', 'unknown')
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source = mail.get('source', 'unknown')
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logger.info(f"Processing Message-ID: {msg_id} for domain: {domain}")
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logger.info(f" From: {source}")
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logger.info(f" To: {recipients}")
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# SES JSON als String serialisieren
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ses_json_string = json.dumps(ses_data)
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# Payload Größe loggen und checken (Safeguard)
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payload_size = len(ses_json_string.encode('utf-8'))
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logger.info(f" Metadata Payload Size: {payload_size} bytes")
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if payload_size > 200000: # Arbitrary Limit < SQS 256KB
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raise ValueError("Payload too large for SQS")
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# Fake SNS Payload
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fake_sns_payload = {
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"Type": "Notification",
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"MessageId": str(uuid.uuid4()),
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"TopicArn": "arn:aws:sns:ses-shim:global-topic",
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"Subject": "Amazon SES Email Receipt Notification",
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"Message": ses_json_string,
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"Timestamp": datetime.utcnow().isoformat() + "Z"
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}
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# Queue URL dynamisch holen
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queue_url = get_queue_url(domain)
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# SQS Send mit Retries
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attempt = 0
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while attempt < MAX_RETRIES:
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try:
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sqs.send_message(
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QueueUrl=queue_url,
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MessageBody=json.dumps(fake_sns_payload)
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)
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logger.info(f"✅ Successfully forwarded {msg_id} to SQS: {queue_url}")
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break
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except ClientError as e:
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attempt += 1
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error_code = e.response['Error']['Code']
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logger.warning(f"Retry {attempt}/{MAX_RETRIES} for SQS send: {error_code} - {str(e)}")
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if attempt == MAX_RETRIES:
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raise
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time.sleep(exponential_backoff(attempt))
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return {'status': 'ok'}
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except Exception as e:
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logger.error(f"❌ Critical Error in Lambda Shim: {str(e)}", exc_info=True)
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raise e |