Setting Up Environment

1. Install required libraries:

pip install --upgrade pip
pip install virtualenv

2. Create Python virtual environment:

virtualenv --python=python3.12 .venv

3. Activate the virtual environment:

source .venv/bin/activate

Install packages

pip install .
pip install -e ".[dev]"

Check tests and coverage

python manager.py run-tests
python manager.py run-tests --test-type integration
python manager.py run-coverage

# Having proper AWS credentials...
python manager.py run-tests --test-type functional --pattern "*.py"

Note: bare pytest/pytest -n auto correctly discovers and runs the tests_*.py unit suite. check_*.py functional tests are deliberately excluded from auto-discovery, since they deploy real AWS resources; pass them to pytest as explicit paths, which is also how to run them with parallelism manager.py doesn’t offer:

Run a specific functional test file (requires AWS credentials):

pytest tests/functional/check_lambda_creation.py

Run a specific test:

pytest tests/functional/check_lambda_creation.py::TestLambdaCreation::test_create_and_invoke_lambda_with_inline_code

Run a few functional test files with limited parallelism (recommended, to avoid AWS rate limits):

pytest tests/functional/*.py -n 2

IMPORTANT: Functional tests deploy real resources to AWS and may incur costs and require AWS credentials configured.

Prerequisites

1. AWS credentials configured.

2. CDK CLI installed npm install -g aws-cdk.

3. Required AWS permissions: * Lambda (create, invoke, delete) * S3 (create bucket, put/get objects, delete) * SNS (create topic, publish) * SQS (create queue, send/receive messages) * CloudFormation (create/update/delete stacks) * IAM (create roles and policies)

Important Notes:

• Tests automatically clean up resources after completion

• Each test uses temporary directories and unique resource names

• Tests include 10-minute timeouts for deployment and cleanup

• All logs captured with DEBUG level for troubleshooting

Complete SNS → SQS → Lambda → S3 Integration

from aws_cdk import App, Environment, Duration, CfnOutput
from aws_cdk.aws_lambda import Code, Runtime
from aws_cdk.aws_lambda_event_sources import SqsEventSource
from aws_cdk.aws_sns_subscriptions import SqsSubscription
from core_aws_cdk.stacks.lambdas import BaseLambdaStack
from core_aws_cdk.stacks.s3 import BaseS3Stack
from core_aws_cdk.stacks.sns import BaseSnsStack
from core_aws_cdk.stacks.sqs import BaseSqsStack

class IntegratedStack(
    BaseSnsStack,
    BaseSqsStack,
    BaseLambdaStack,
    BaseS3Stack
):
    """ My Custom Stack """

app = App()

stack = IntegratedStack(
    app,
    "IntegratedStack",
    env=Environment(
        account="123456789",
        region="us-east-1"
    ))

# Create S3 bucket
bucket = stack.create_bucket(
    bucket_id="DataBucket",
    bucket_name=None  # Auto-generate
)

# Create SQS queue with DLQ
queue = stack.create_sqs_queue(
    queue_id="ProcessQueue",
    queue_name="process-queue",
    with_dlq=True,
    dlq_id="ProcessQueueDLQ",
    max_receive_count=3
)

# Create SNS topic
topic = stack.create_sns_topic(
    topic_id="EventTopic",
    topic_name="event-topic"
)

# Subscribe queue to topic
topic.add_subscription(SqsSubscription(queue))

# Create Lambda processor
lambda_function = stack.create_lambda(
    function_id="Processor",
    handler="handler.lambda_handler",
    code=Code.from_asset("./lambda"),
    runtime=Runtime.PYTHON_3_12,
    timeout=Duration.minutes(5),
    environment={"BUCKET_NAME": bucket.bucket_name}
)

# Configure SQS as Lambda trigger
lambda_function.add_event_source(SqsEventSource(queue))

# Grant permissions
bucket.grant_write(lambda_function)

# Export outputs
CfnOutput(stack, "TopicArn", value=topic.topic_arn)
CfnOutput(stack, "BucketName", value=bucket.bucket_name)

app.synth()

Issue: CDK version mismatch

Solution: Ensure CDK CLI version matches library version

npm install -g aws-cdk@latest
cdk --version

Issue: Node.js version warning

Solution: Ensure Node.js v20 or v22 is installed and accessible

node --version
which node