awstin 0.0.3

Utilities for building and testing AWS applications in Python

awstin

Utilities for building and testing AWS applications in Python.

Lambdas

Production

Lambda events can be given data models that are created from the event and context:

from awstin.awslambda.api import LambdaEvent


class CustomEvent(LambdaEvent):
    def __init__(self, request_id, memory_limit):
        self.request_id = request_id
        self.memory_limit = memory_limit

    @classmethod
    def _from_event(cls, event, context):
        request_id = event["requestContext"]["requestId"]
        memory_limit = context["memory_limit_in_mb"]
        return cls(request_id, memory_limit)

Lambda handlers can then be created using the lambda_handler decorator factory, which takes as an input the data model for the lambda event.

from awstin.awslambda.api import lambda_handler


@lambda_handler(CustomEvent)
def handle_custom_event(event):
    print(event.request_id)
    print(event.memory_limit)

DynamoDB

Production

The DynamoDB class currently gives dict-like access to boto3 Tables and their contents. This requires either the TEST_DYNAMODB_ENDPOINT (for integration testing) or AWS_REGION (for production) endpoints to be set.

from awstin.dynamodb.api import DynamoDB


dynamodb = DynamoDB()

# List of available tables
tables = dynamodb.tables

# Access a single table
table = dynamodb["my_table"]

# Tables that only have a partition key can be accessed directly by their
# partition key
item = table["an_item"]

# Full primary key access is also available
item = table[{"primary_key_name": "an_item"}]

Testing

For integration testing, a context manager to create and then tear-down a DynamoDB table is provided. More flexible control over the created table is planned.

from awstin.dynamodb.testing import temporary_dynamodb_table


with temporary_dynamodb_table("table_name", "hashkey_name") as table:
    item = {
        "hashkey_name": "test_value",
        "another_key": 5,
    }
    table.put_item(item)

SNS

SNS topics can be retrieved by name and published to with the message directly:

from awstin.sns.api import SNSTopic


topic = SNSTopic("topic-name")
message_id = topic.publish("a message")