基于AWS Lambda与SES实现带文件上传的网站联系表单问询

Got it, let's walk through how to add file upload functionality to your existing AWS Lambda + SES contact form. I’ve built this exact setup before, so here’s a step-by-step breakdown with actionable code snippets:

First, you’ll need to adjust your form to support file uploads—plain JSON won’t work here, so we’ll use multipart/form-data encoding. Here’s a modified form example:

<form id="contactForm" enctype="multipart/form-data">
  <input type="text" name="name" placeholder="Your Name" required>
  <input type="email" name="email" placeholder="Your Email" required>
  <textarea name="message" placeholder="Your Message" rows="4" required></textarea>
  <!-- Add file input with accepted types -->
  <input type="file" name="attachment" accept=".pdf,.doc,.docx,.jpg,.png" required>
  <button type="submit">Send Message</button>
</form>

Next, update your frontend JavaScript to send the form as FormData instead of a JSON string:

document.getElementById('contactForm').addEventListener('submit', async (e) => {
  e.preventDefault();
  const formData = new FormData(e.target);
  
  try {
    const response = await fetch('YOUR_LAMBDA_API_GATEWAY_ENDPOINT', {
      method: 'POST',
      body: formData
    });
    const result = await response.json();
    alert('Message sent successfully with attachment!');
    e.target.reset();
  } catch (error) {
    console.error('Submission error:', error);
    alert('Failed to send your message. Please try again later.');
  }
});

Lambda can’t natively parse multipart/form-data, so we’ll use the aws-lambda-multipart-parser package to handle file extraction. Here’s the updated Node.js function:

First, install the dependency:

npm install aws-lambda-multipart-parser

(You can either package this with your Lambda code or add it as a Lambda Layer for reusability.)

Then the Lambda code:

const AWS = require('aws-sdk');
const parser = require('aws-lambda-multipart-parser');
const ses = new AWS.SES({ region: 'YOUR_AWS_REGION' });

exports.handler = async (event) => {
  try {
    // Parse incoming multipart form data
    const formData = parser.parse(event);
    
    // Extract form fields and attached file
    const { name, email, message } = formData;
    const attachment = formData.files[0]; // Get the first uploaded file

    // Encode file content to Base64 (required for SES attachments)
    const fileBase64 = attachment.content.toString('base64');

    // Build SES email parameters with attachment
    const emailParams = {
      Destination: {
        ToAddresses: ['YOUR_SITE_OWNER_EMAIL@example.com']
      },
      Message: {
        Body: {
          Text: {
            Data: `New contact form submission:\n\nName: ${name}\nEmail: ${email}\nMessage:\n${message}`
          }
        },
        Subject: {
          Data: `Contact Form: ${name} sent a message with attachment`
        }
      },
      Source: 'YOUR_VERIFIED_SES_EMAIL@example.com',
      Attachments: [
        {
          Filename: attachment.filename,
          ContentType: attachment.contentType,
          Content: fileBase64
        }
      ]
    };

    // Send the email via SES
    await ses.sendEmail(emailParams).promise();

    return {
      statusCode: 200,
      body: JSON.stringify({ success: true, message: 'Email sent with attachment' })
    };
  } catch (error) {
    console.error('SES send error:', error);
    return {
      statusCode: 500,
      body: JSON.stringify({ success: false, error: error.message })
    };
  }
};

Make sure your Lambda execution role has permission to send emails via SES. Add this policy to the role:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "ses:SendEmail",
      "Resource": "*"
    }
  ]
}

Note: If you’re still in SES sandbox mode, both the sender and recipient emails must be verified in the AWS SES console.

• Submit the form with a valid file (match the accept types in your HTML)
• Check CloudWatch Logs for Lambda to debug any parsing or SES errors
• Verify the recipient inbox receives the email with the attached file

内容的提问来源于stack exchange，提问作者AynonT