Lambda HTML to PDF

This Lambda function renders HTML into a PDF using Puppeteer, with support for advanced metadata, viewer preferences, and security encryption (password protection and permissions).

Lambda Function Setup

1. Install AWS CLI and run aws configure to setup access to AWS with your credentials
2. Create an IAM Role to access the S3 bucket from the Lambda function by running ./create-role.sh. Be sure to document the ARN of the new role output by the script.
3. Publish an AWS Lambda Layer with Chromium to render the HTML by running ./publish-layer.sh. Be sure to document the ARN of the Lambda Layer output by the script.
4. Deploy the package to AWS Lambda by running ./deploy.sh
5. Test the AWS Lambda function by running ./test-lambda.sh
6. Create an AWS API Gateway Endpoint by running ./setup-api.sh
7. Manage the AWS API Gateway API Keys by running ./manage-keys.sh

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API Gateway

Endpoint Overview

• Method: POST
• Content-Type: application/json
• Auth: Requires x-api-key header.

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JSON Payload Structure

The input payload is a JSON object with the following top-level fields:

Field	Type	Required	Description
htmlBody	string	Yes	The full HTML content to render. CSS/Images must be inline (base64) or accessible.
fileName	string	Yes	The desired filename (e.g., report.pdf).
bucketName	string	Yes	The S3 bucket where the file will be saved.
puppeteer	object	No	Rendering options (margins, orientation, format).
pdfLib	object	No	Post-processing options (metadata, encryption, viewer settings).

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1. Puppeteer Options (puppeteer)

Controls how the browser renders the PDF.

"puppeteer": {
  "format": "Letter",
  "landscape": true,
  "printBackground": true,
  "margin": { "top": "1cm", "right": "1cm", "bottom": "1cm", "left": "1cm" },
  "scale": 1.0,
  "displayHeaderFooter": false
}

Option	Type	Default	Description
format	string	"Letter"	Page size. Valid: Letter, Legal, Tabloid, A0–A6.
landscape	boolean	false	true for horizontal orientation, false for vertical.
printBackground	boolean	true	Set false to suppress background colors/images.
scale	number	1.0	Scale of the webpage rendering (0.1 to 2.0).
margin	object	1cm (all)	Object with top, right, bottom, left. Units: px, cm, in.
displayHeaderFooter	boolean	false	true to show headers/footers.
headerTemplate	string	""	HTML for header. Supports variables: <span class='pageNumber'></span>, <span class='totalPages'></span>, <span class='date'></span>, <span class='title'></span>.
footerTemplate	string	""	HTML for footer. Same variables as header.
pageRanges	string	All	Specific pages to print (e.g., "1-5, 8, 11-13").
preferCSSPageSize	boolean	false	If true, prioritize @page CSS rules over the format option.

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2. Metadata Options (pdfLib.metadata)

Sets standard PDF properties visible in document properties.

"pdfLib": {
  "metadata": {
    "title": "Quarterly Report",
    "author": "Finance Dept",
    "subject": "Q3 Financials",
    "keywords": ["finance", "2025", "confidential"],
    "creator": "My App v2.0",
    "creationDate": "2025-12-13T12:00:00Z"
  }
}

Option	Type	Description
title	string	The document title.
author	string	The name of the person/entity creating the file.
subject	string	The subject matter description.
keywords	array	List of keywords strings.
creator	string	The name of the app that created the original content.
producer	string	The name of the app that converted it to PDF.
creationDate	string	ISO 8601 Date string (e.g., 2025-01-01T00:00:00Z).
modificationDate	string	ISO 8601 Date string.

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3. Viewer Preferences (pdfLib.viewerPreferences)

Controls how the PDF opens in the user's viewer (e.g., Adobe Acrobat).

"pdfLib": {
  "viewerPreferences": {
    "hideToolbar": true,
    "fitWindow": true
  }
}

Option	Type	Description
hideToolbar	boolean	Hides the viewer's toolbar (save, print buttons, etc.).
hideMenubar	boolean	Hides the viewer's menu bar (File, Edit, etc.).
hideWindowUI	boolean	Hides UI elements like scrollbars.
fitWindow	boolean	Resizes the window to fit the document page size.
centerWindow	boolean	Positions the window in the center of the screen.
displayDocTitle	boolean	Shows the Document Title in the title bar instead of the filename.

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4. Encryption & Permissions (pdfLib.encryption)

Secures the PDF with 128-bit RC4 encryption.

Important: To enforce permissions, you must provide an ownerPassword different from the userPassword.

"pdfLib": {
  "encryption": {
    "userPassword": "reader123",
    "ownerPassword": "admin456",
    "permissions": {
      "printing": "none",
      "copying": false
    }
  }
}

Option	Type	Default	Description
userPassword	string	""	Password required to open the file.
ownerPassword	string	""	Password required to change permissions.
permissions	object	Allowed	See table below.

Permission Flags

Flag	Type	Values	Description
printing	string	'highResolution', 'lowResolution', 'none'	Controls printing ability.
modifying	boolean	true / false	Allow modifying document content.
copying	boolean	true / false	Allow selecting and copying text/images.
annotating	boolean	true / false	Allow adding comments/annotations.
fillingForms	boolean	true / false	Allow filling in form fields.
contentAccessibility	boolean	true / false	Allow screen readers to access text.
documentAssembly	boolean	true / false	Allow inserting/rotating/deleting pages.

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Example Payload (Full Feature)

{
  "bucketName": "my-reports-bucket",
  "fileName": "secure_report_001.pdf",
  "htmlBody": "<html><body><h1>Confidential</h1></body></html>",
  
  "puppeteer": {
    "format": "A4",
    "landscape": true,
    "margin": { "top": "2cm", "bottom": "2cm", "left": "1cm", "right": "1cm" },
    "displayHeaderFooter": true,
    "headerTemplate": "<div style='font-size:10px;'>SECRET</div>",
    "footerTemplate": "<div style='font-size:10px;'>Page <span class='pageNumber'></span></div>"
  },
  
  "pdfLib": {
    "metadata": {
      "title": "Q3 Secret Report",
      "author": "Chief Financial Officer"
    },
    "viewerPreferences": {
      "hideToolbar": true,
      "displayDocTitle": true
    },
    "encryption": {
      "userPassword": "password123",
      "ownerPassword": "admin_password_999",
      "permissions": {
        "printing": "none",
        "copying": false,
        "modifying": false
      }
    }
  }
}