robinsingh1 / domovoi

AWS Lambda event handler manager

Domovoi: AWS Lambda event handler manager

Domovoi is an extension to AWS Labs Chalice to handle AWS Lambda event sources other than HTTP requests through API Gateway. Domovoi lets you easily configure and deploy a Lambda function to run on a schedule or in response to an SNS push notification:

import json, boto3, domovoi

app = domovoi.Domovoi()

@app.scheduled_function("cron(0 18 ? * MON-FRI *)")
def foo(event, context):
    context.log("foo invoked at 06:00pm (UTC) every Mon-Fri")
    return dict(result=True)

@app.scheduled_function("rate(1 minute)")
def bar(event, context):
    context.log("bar invoked once a minute")
    boto3.resource("sns").create_topic(Name="bartender").publish(Message=json.dumps({"beer": 1}))
    return dict(result="Work work work")

@app.sns_topic_subscriber("bartender")
def tend(event, context):
    message = json.loads(event["Records"][0]["Sns"]["Message"])
    context.log(dict(beer="Quadrupel", quantity=message["beer"]))

@app.cloudwatch_event_handler(source=["aws.ecs"])
def monitor_ecs_events(event, context):
    message = json.loads(event["Records"][0]["Sns"]["Message"])
    context.log("Got an event from ECS: {}".format(message))

@app.s3_event_handler(bucket="myS3bucket", events=["s3:ObjectCreated:*"], prefix="foo", suffix=".bar")
def monitor_s3(event, context):
    message = json.loads(event["Records"][0]["Sns"]["Message"])
    context.log("Got an event from S3: {}".format(message))

Installation

pip install domovoi

Usage

First-time setup:

chalice new-project

Replace the Chalice app entry point (in app.py) with the Domovoi app entry point as above, then deploy the event handlers:

domovoi deploy

To stage files into the deployment package, use a domovoilib directory in your project where you would use chalicelib in Chalice. For example, my_project/domovoilib/rds_cert.pem becomes /var/task/domovoilib/rds_cert.pem with your function executing in /var/task/app.py with /var/task as the working directory. See the Chalice docs for more information on how to set up Chalice configuration.

Supported event types

See http://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html for an overview of event sources that can be used to trigger Lambda functions. Domovoi supports the following event sources:

• SNS subscriptions
• CloudWatch Events rule targets, including CloudWatch Scheduled Events (see http://docs.aws.amazon.com/AmazonCloudWatch/latest/events/EventTypes.html for a list of event types supported by CloudWatch Events)
• S3 events

TODO:

• CloudWatch Logs filter subscriptions
• DynamoDB events
• SES (email) events

Links

• Project home page (GitHub)
• Documentation (Read the Docs)
• Package distribution (PyPI)
• Change log

Bugs

Please report bugs, issues, feature requests, etc. on GitHub.

License

Licensed under the terms of the Apache License, Version 2.0.