PDF Service

A production ready PDF generation service powered by Gotenberg, with API key authentication via Caddy.

Overview

This setup provides:

• Gotenberg — Converts HTML, URLs, and Office files to PDF using headless Chromium
• Caddy — Reverse proxy handling SSL termination and API key authentication

Quick Start

1. Clone this repo
2. Update Caddyfile with your domain
3. Add your API keys to api_keys.caddy
4. Start the containers:

docker compose up -d

Caddy automatically provisions SSL certificates via Let's Encrypt.

Configuration

API Keys

Add or remove keys in api_keys.caddy:

map {header.X-Api-Key} {is_authorized} {
    "your-api-key-here"     "true"
    "another-api-key"       "true"
    
    default "false"
}

You can generate secure keys using this:

openssl rand -hex 16

After updating, hot reload Caddy without downtime:

docker compose exec caddy caddy reload --config /etc/caddy/Caddyfile

Domain

Update the domain in Caddyfile:

pdf.example.com {
    # ...
}

Usage

Send requests with your API key in the X-Api-Key header:

# Health check
curl https://pdf.example.com/health

# Generate PDF from HTML
curl -X POST \
  -H "X-Api-Key: your-api-key-here" \
  -F "files=@index.html;filename=index.html" \
  https://pdf.example.com/forms/chromium/convert/html \
  -o output.pdf

See Gotenberg documentation for all available endpoints.

PHP Integration

Use the official gotenberg-php package to integrate with your PHP application:

composer require gotenberg/gotenberg-php

For API key authentication, add a custom HTTP client that includes the X-Api-Key header with each request.

Resource Limits

Default limits in docker-compose.yml:

Service	Memory	CPU
Caddy	256MB	-
Gotenberg	2GB	2

Adjust based on your workload.

Notes

• LibreOffice routes are disabled by default. Enable in docker-compose.yml if you need Office file conversion.
• Gotenberg is not exposed directly—all traffic goes through Caddy.