MD2PDF Converter

Status: Active

Namespace: md2pdf

Port: 3000

Ingress: md2pdf.babdelka.com

Overview

MD2PDF is a self-hosted web utility for writing and converting Markdown documents into beautifully styled PDFs with real-time preview and client-side Mermaid flowchart diagram rendering.

Key Capabilities

Dual-Pane Editor: Live Markdown text area on the left with instant synchronized preview on the right.
7 Thematic Styles: Includes Modern (Default), GitHub, Dracula (Dark), Nord, Solarized Light, Academic (LaTeX serif), and Minimalist Elegant.
Mermaid.js Flowcharts: Automatically parses ` ```mermaid ` code fences and converts them into SVG flowcharts and sequence diagrams before PDF generation.
Serverless-Grade Headless Rendering: Utilizes system Chromium via Puppeteer to render exact print-quality CSS page breaks, headers, footers, and margins.

Architecture & Container Configuration

User Browser
    │  (Markdown text + Selected Theme + Rendered Mermaid SVGs)
    ▼
Gateway API (my-gateway) -> md2pdf-route (md2pdf.babdelka.com)
    │
    ▼
Express.js Service (:3000)
    │
    ▼
Puppeteer (Chromium /usr/bin/chromium)
    │  (HTML with inline CSS + theme rules)
    ▼
Generated PDF Stream (application/pdf)

Container Details

Base Image: node:20-bookworm-slim
Chromium: System-installed /usr/bin/chromium (no download overhead)
Init System: dumb-init handling PID 1 zombie processes for headless browsers
Memory Shm: Mounted emptyDir with medium: Memory (512Mi) at /dev/shm to prevent Chromium sandbox crashes under concurrency.

API Endpoints

1. `POST /api/convert`

Renders Markdown or compiled HTML into a downloadable PDF document.

Request Body (application/json):

{
  "markdown": "# Document Title\n\nContent here...",
  "theme": "academic",
  "renderedHtml": "<h1 id=\"document-title\">Document Title</h1><p>Content here...</p>",
  "options": {
    "format": "A4",
    "landscape": false,
    "printBackground": true
  }
}

Response: Binary stream (application/pdf) with Content-Disposition: attachment; filename="document.pdf".

2. `GET /health`

Liveness and readiness check. Returns status 200 OK with { "status": "healthy", "uptime": 1234 }.

Operations & Troubleshooting

Viewing Logs

kubectl logs -n md2pdf -l app=md2pdf -f

Restarting the Service

kubectl rollout restart deployment/md2pdf -n md2pdf

Common Issues

Chromium crash on large diagrams: Check /dev/shm memory allocation in apps/src/md2pdf/deployment.yaml. The emptyDir must allow at least 256Mi–512Mi.