PDF invoice is not generated in my S3 bucket

Question

I wrote a lambda function in using Python where a customer makes an order and the receipt will be generated in form of PDF in S3 This is the code in my lambda function import json import boto3 from datetime import datetime, timedelta import uuid from io import BytesIO import base64 # For PDF generation, we'll use a simpler approach with HTML to PDF # Since ReportLab requires additional layers in Lambda dynamodb = boto3.resource('dynamodb') s3 = boto3.client('s3') lambda_client = boto3.client('lambda') orders_table = dynamodb.Table('TechHub-Orders') customers_table = dynamodb.Table('TechHub-Customers') def lambda_handler(event, context): """ Generate PDF invoice for order """ try: order_id = event.get('order_id') if not order_id: return { 'statusCode': 400, 'body': json.dumps({'error': 'Order ID is required'}) } # Get order details order_response = orders_table.get_item(Key={'order_id': order_id}) if 'Item' not in order_response: return { 'statusCode': 404, 'body': json.dumps({'error': 'Order not found'}) } order = order_response['Item'] # Get customer details customer_response = customers_table.get_item(Key={'customer_id': order['customer_id']}) customer = customer_response.get('Item', {}) # Generate HTML invoice html_content = generate_invoice_html(order, customer) # Convert HTML to PDF (using weasyprint approach for Lambda) pdf_content = html_to_pdf_simple(html_content) # Save to S3 s3_key = f"invoices/{order_id}/{order_id}_invoice.pdf" bucket_name = 'techhub-do5' # Replace with your bucket name s3.put_object( Bucket=bucket_name, Key=s3_key, Body=pdf_content, ContentType='application/pdf' ) # Generate pre-signed URL pdf_url = s3.generate_presigned_url( 'get_object', Params={'Bucket': bucket_name, 'Key': s3_key}, ExpiresIn=86400 # 24 hours ) # Trigger notification send_invoice_notification(order, customer, pdf_url) return { 'statusCode': 200, 'body': json.dumps({ 'invoice_url': pdf_url, 'message': 'PDF Invoice generated successfully', 'order_id': order_id }) } except Exception as e: print(f"Invoice generation error: {str(e)}") import traceback traceback.print_exc() return { 'statusCode': 500, 'body': json.dumps({'error': 'Failed to generate PDF invoice', 'details': str(e)}) } def generate_invoice_html(order, customer): """ Generate professional HTML invoice """ # Calculate totals subtotal = float(order.get('total_amount', 0)) tax_rate = 0.075 # 7.5% VAT in Nigeria tax_amount = subtotal * tax_rate total_amount = subtotal + tax_amount html_content = f""" Invoice - {order['order_id'][:8].upper()}

INVOICE

Invoice Details

Invoice Number: {order['order_id'][:8].upper()}

Date: {datetime.utcnow().strftime('%B %d, %Y')}

Due Date: {(datetime.utcnow() + timedelta(days=30)).strftime('%B %d, %Y')}

Order ID: {order['order_id']}

Bill To

{customer.get('name', 'N/A')}

Email: {customer.get('email', 'N/A')}

Phone: {customer.get('phone', 'N/A')}

Customer ID: {customer.get('customer_id', 'N/A')}

""" # Add items for item in order.get('items', []): html_content += f""" """ html_content += f"""

Description	Quantity	Unit Price	Total
{item.get('product_name', 'N/A')}	{item.get('quantity', 0)}	₦{float(item.get('unit_price', 0)):,.2f}	₦{float(item.get('total_price', 0)):,.2f}

Subtotal:	₦{subtotal:,.2f}
VAT (7.5%):	₦{tax_amount:,.2f}
Total Amount:	₦{total_amount:,.2f}

Payment Terms & Information

Payment Due: Net 30 days from invoice date

Bank Transfer Details:

Account Name: TechHub Nigeria Limited
Account Number: 8
Bank: Access Bank Nigeria
Sort Code:

""" return html_content def html_to_pdf_simple(html_content): """ Convert HTML to PDF using a simple approach For production, you'd want to use a proper PDF generation service """ # This is a simplified approach - for production use weasyprint or similar # For now, we'll save as HTML and let the client handle PDF conversion # or use a PDF generation service try: # For demo purposes, we'll use pdfkit if available in Lambda layer # Otherwise, save as HTML with PDF-like styling import pdfkit pdf_content = pdfkit.from_string(html_content, False) return pdf_content except ImportError: # Fallback: return HTML content for now # In production, add a PDF generation layer print("PDF generation library not available, returning HTML") return html_content.encode('utf-8') def send_invoice_notification(order, customer, pdf_url): """ Send invoice notification to customer """ try: # Trigger notification Lambda payload = { 'type': 'invoice_ready', 'customer_email': customer.get('email'), 'customer_phone': customer.get('phone'), 'data': { 'order_id': order['order_id'], 'invoice_url': pdf_url, 'total_amount': float(order.get('total_amount', 0)) } def send_invoice_notification(email, phone, data): """ Send invoice ready notification with PDF attachment """ if email: try: # Email with invoice link html_body = f"""

Your TechHub Nigeria Invoice is Ready!

Dear Valued Customer,

Your invoice for Order #{data.get('order_id', '')[:8].upper()} is now ready.

Total Amount: ₦{data.get('total_amount', 0):,.2f}

Download Invoice PDF

Payment is due within 30 days. Thank you for your business!

Best regards,
TechHub Nigeria Team

""" ses.send_email( Source=', # Replace with your verified email Destination={'ToAddresses': [email]}, Message={ 'Subject': {'Data': f'Invoice Ready - Order #{data.get("order_id", "")[:8].upper()}'}, 'Body': { 'Html': {'Data': html_body}, 'Text': {'Data': f'Your invoice is ready! Download: {data.get("invoice_url", "")}'} } } ) except Exception as e: print(f"Email send error: {e}") if phone: try: sns.publish( PhoneNumber=phone, Message=f'TechHub: Invoice ready for Order #{data.get("order_id", "")[:8]}. Total: ₦{data.get("total_amount", 0):,.2f}. Check your email for PDF.' ) except Exception as e: print(f"SMS send error: {e}") } lambda_client.invoke( FunctionName='techhub-notifications', InvocationType='Event', Payload=json.dumps(payload) ) except Exception as e: print(f"Notification error: {str(e)}")

re:Post Agent · Answer

Based on your code, there are several issues that could be preventing the PDF invoice from being generated in your S3 bucket:

1. The most critical issue is in your `html_to_pdf_simple` function. You're trying to use `pdfkit` which requires external dependencies like wkhtmltopdf. These aren't available in the standard Lambda environment unless you've added them as a Lambda layer. When the import fails, your fallback is to simply return the HTML content encoded as bytes, not an actual PDF.

2. Your error handling might be hiding the actual error. While you're printing the error message and traceback, you should check CloudWatch logs to see what specific error is occurring.

3. The `send_invoice_notification` function has a nested function definition inside it, which would cause a syntax error. This nested function is also trying to use `ses` and `sns` clients that aren't defined in your code.

Here are some recommendations to fix the issues:

1. For PDF generation in Lambda, consider one of these approaches:
- Use a Lambda layer that includes wkhtmltopdf and pdfkit
- Use a simpler PDF generation library like ReportLab that has fewer dependencies
- Use AWS services like API Gateway to call a containerized service that can handle PDF generation
- Consider using a third-party PDF generation service

2. Check your Lambda function's IAM permissions to ensure it has proper access to write to the S3 bucket.

3. Verify that the DynamoDB tables exist and that your Lambda function has permissions to read from them.

4. Fix the nested function definition in `send_invoice_notification`.

5. Increase your Lambda timeout if the PDF generation is taking longer than expected.

6. Add more detailed logging throughout your code to identify exactly where the process is failing.

To debug this issue, I recommend adding explicit logging statements before and after each major operation (retrieving data from DynamoDB, generating HTML, converting to PDF, uploading to S3) to pinpoint where the process is breaking down.  
**Sources**  
[AWS Lambda Not Writing to DynamoDB After S3 Upload Trigger | AWS re:Post](https://repost.aws/questions/QUGE_zDUnJQ9WHjKfXLFFXsg/aws-lambda-not-writing-to-dynamodb-after-s3-upload-trigger)  
[Define Lambda function handler in Python - AWS Lambda](https://docs.aws.amazon.com/lambda/latest/dg/python-handler.html)  
[Create a serverless file-processing app - AWS Lambda](https://docs.aws.amazon.com/lambda/latest/dg/file-processing-app.html)

PDF invoice is not generated in my S3 bucket

For PDF generation, we'll use a simpler approach with HTML to PDF

Since ReportLab requires additional layers in Lambda

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