FastAPI SQS Integration

This project demonstrates how to use FastAPI to send messages to an AWS SQS queue and how to set up an AWS Lambda function to process those messages.

Prerequisites

Python 3.10+
AWS Account
AWS CLI configured with the necessary permissions
FastAPI
Uvicorn
boto3
python-dotenv

Setup

1. Clone the repository

git clone https://github.com/dcsm8/aws_sqs_example.git
cd aws_sqs_example

2. Create a virtual environment

python -m venv venv
source venv/bin/activate  # On Windows use `venv\Scripts\activate`

3. Install dependencies

pip install fastapi uvicorn boto3 python-dotenv

4. Create a `.env` file

Create a .env file in the root directory and add your AWS credentials:

AWS_ACCESS_KEY_ID=your_access_key_id
AWS_SECRET_ACCESS_KEY=your_secret_access_key
AWS_REGION=us-east-1  # Change to your desired region

5. Update `main.py`

Update the queue_url in main.py with your actual SQS queue URL:

queue_url = 'https://sqs.us-east-1.amazonaws.com/YOUR_ACCOUNT_ID/MyQueue'  # Replace with your Queue URL

Running the Application

Start the FastAPI application:

uvicorn main:app --reload

Testing the API

You can test sending messages to the SQS queue using a tool like Postman

Using Postman:

Set the request type to POST.
Set the URL to http://127.0.0.1:8000/send-message/.
Set the header Content-Type to application/json.

Set the body to:

{
    "action": "process_data",
    "data": {
        "key1": "value1",
        "key2": "value2"
    }
}

Setting Up the Lambda Function

1. Create the Lambda Function

Log in to the AWS Management Console.
Navigate to the Lambda Console.
Create a new Lambda function named ProcessSQSEvent with Python 3.10 runtime.

2. Write the Lambda Function Code

Here is an example Lambda function code:

import json

def lambda_handler(event, context):
    for record in event['Records']:
        body = record['body']
        print(f'Received message: {body}')
        try:
            message = json.loads(body)
            print(f'Parsed message: {message}')
            if 'action' in message:
                if message['action'] == 'process_data':
                    print('Processing data...')
                elif message['action'] == 'send_email':
                    print('Sending email...')
                else:
                    print(f'Unknown action: {message["action"]}')
        except json.JSONDecodeError:
            print('Could not parse message body as JSON')
    return {
        'statusCode': 200,
        'body': json.dumps('Messages processed successfully!')
    }

3. Configure Lambda to Trigger on SQS Messages

Add an SQS trigger to your Lambda function and select your SQS queue.
Ensure the Lambda function's execution role has permissions to read from the SQS queue.

4. Test the Setup

Send messages using your FastAPI application and check the Lambda logs in CloudWatch to verify the messages are processed correctly.

dcsm8/aws_sqs_example