def lambda_handler()

in ingest_er7_service/ingest_er7_lambda.py [0:0]

• 44 lines of code
• 5 McCabe index (conditional complexity)

def lambda_handler(event, context):
  idToken = event['headers']['authorization']
  claims = event['requestContext']['authorizer']['jwt']['claims']
  source = claims.get('custom:write','')
  
  if len(source) == 0:
    logger.warn("Unauthorized write attempt rejected")
    return __get_response("", 403, "Insufficient privileges to write")
    
  logger.debug("Source: "+source) 

  # Verify the payload is unique through the SHA256[:12] of B64 message (mId)
  logger.debug("Checking that message is unique")
  body = json.loads(event["body"]) # Body is a JSON payload passed in
  msg = body['msg']
  msg_hash = hashlib.sha256(msg.encode()).hexdigest()[:12]
  logger.debug("Message hash: "+msg_hash)

  count = table.query(
    KeyConditionExpression=Key('source').eq(source) & Key('message_id').eq(msg_hash)
  )['Count']
    
  if count > 0:
    logger.warn("Duplicate payload rejected")
    return __get_response(msg_hash, 400, "Rejected due to being a duplicate")
    
  logger.debug("Message {} is unique".format(msg_hash))

  # Invoke our parser
  response = sf.start_sync_execution(
    stateMachineArn=os.environ['state_machine'],
    input= json.dumps({'Message':msg})
  )
  status = response['status']
  logger.info(response)
  
  if status == 'SUCCEEDED':
    state = "parsed"
    json_msg = json.loads(response['output'])['json']
    logger.info("JSON: {}".format(json_msg))
  else:
    state = "error"
    logger.warn(json.loads(response['cause'])['errorMessage'])

  # Store the message (after parsing attempt since we want that status on the tags)
  key = "source={}/protocol=hl7v2/format=er7/zone=ingest/{}.txt".format(source, msg_hash)
  tags = 'source={}&state={}'.format(source, state)
  __store_message(idToken, msg, key, tags, msg_hash, source)
  logger.info("Message written to bucket '{}' with key '{}'".format(os.environ['bucket_name'], key))
  
  if status == 'SUCCEEDED':
    __publish_to_topic(json.dumps(json_msg), 'json', state, key)
    return __get_response(msg_hash, 201, 'Message added and parsed')
  else:
    __publish_to_topic(msg, 'unknown', state, key)
    return __get_response(msg_hash, 400, 'Message added, but could not be parsed')
  logger.info("Published to SNS topic")