Files
saladeaula.digital/streams-events/app/events/docs_into_eventbus.py

97 lines
2.6 KiB
Python

import decimal
import json
import math
from typing import TYPE_CHECKING
import boto3
from aws_lambda_powertools import Logger, Tracer
from aws_lambda_powertools.utilities.batch import (
BatchProcessor,
EventType,
process_partial_response,
)
from aws_lambda_powertools.utilities.data_classes.dynamo_db_stream_event import (
DynamoDBRecord,
DynamoDBRecordEventName,
)
from aws_lambda_powertools.utilities.typing import LambdaContext
from layercake.dateutils import now, ttl
from utils import diff, table_from_arn
if TYPE_CHECKING:
from mypy_boto3_events.client import EventBridgeClient
else:
EventBridgeClient = object
client: EventBridgeClient = boto3.client('events')
processor = BatchProcessor(event_type=EventType.DynamoDBStreams)
tracer = Tracer()
logger = Logger()
@tracer.capture_method
def record_handler(record: DynamoDBRecord):
detail_type = record.raw_event['eventName']
table_name: str = table_from_arn(record.event_source_arn) # type: ignore
new_image: dict = record.dynamodb.new_image # type: ignore
old_image: dict = record.dynamodb.old_image # type: ignore
record_ttl: int | None = old_image.get('ttl')
modified = diff(new_image, old_image)
now_ = now()
# Should be EXPIRE if event is REMOVE and TTL has elapsed
if (
record.event_name is DynamoDBRecordEventName.REMOVE
and record_ttl
and ttl() >= record_ttl
):
detail_type = 'EXPIRE'
detail = {
'keys': record.dynamodb.keys, # type: ignore
'new_image': new_image,
'old_image': old_image,
'modified': modified,
}
result = client.put_events(
Entries=[
{
'Source': record.event_source, # type: ignore
'DetailType': detail_type,
'Resources': [table_name],
'Detail': json.dumps(detail, cls=JSONEncoder),
'Time': now_,
}
]
)
logger.info('Event result', result=result)
@tracer.capture_lambda_handler
def lambda_handler(event: dict, context: LambdaContext):
return process_partial_response(
event=event,
record_handler=record_handler,
processor=processor,
context=context,
)
class JSONEncoder(json.JSONEncoder):
def default(self, o):
if isinstance(o, decimal.Decimal):
if o.is_nan():
return math.nan
if o % 1 != 0:
return float(o.quantize(decimal.Decimal('0.00')))
return int(o)
if isinstance(o, set):
return list(o)
return super().default(o)