Halo

The Halo Lib is a python based library utilizing Serverless technology and microservices architecture

Halo provides the following features:

• Flask development for AWS Lambda & Dynamodb
• correlation id across microservices
• structured json based logging
• sample debug log in production
• support for microservice transactions with the saga pattern
• using SSM Parameter Store over Lambda env variables
• Serverless Error Handling & trace id for end users
• Lambda timeout management for slow HTTP responses
• ootb support for Idempotent service invocations (md5)

If you are building a Python web app running on AWS Lambda (Django or Flask), use this library to manage api transactions:

            sagax = load_saga("test", jsonx, schema)
            payloads = {"BookHotel": {"abc": "def"}, "BookFlight": {"abc": "def"}, "BookRental": {"abc": "def"},
                        "CancelHotel": {"abc": "def"}, "CancelFlight": {"abc": "def"}, "CancelRental": {"abc": "def"}}
            apis = {"BookHotel": self.create_api1, "BookFlight": self.create_api2, "BookRental": self.create_api3,
                    "CancelHotel": self.create_api4, "CancelFlight": self.create_api5, "CancelRental": self.create_api6}
            try:
                self.context = Util.get_lambda_context(request)
                ret = sagax.execute(self.req_context, payloads, apis)
                return {"saga": "good"}, 200
            except SagaRollBack as e:
                return {"saga": "bad"}, 500

License

This project is licensed under the MIT License

Acknowledgments

• Yan Cui - https://theburningmonk.com
• flowpl - https://github.com/flowpl/saga_py