S3 Markdown

WordPress plugin that renders markdown files from an AWS S3 bucket via shortcode. Content is cached for 24 hours with manual flush available from the admin settings.

Installation

Copy the s3-markdown directory into wp-content/plugins/ and activate in WP Admin > Plugins.

Configuration

Go to Settings > S3 Markdown and enter:

• Bucket Name — your S3 bucket
• Region — e.g. eu-west-2 (defaults to us-east-1)
• Access Key ID — IAM user with s3:GetObject permission on the bucket
• Secret Access Key

Usage

[s3md]                         <!-- renders index.md -->
[s3md file="notes/update.md"]  <!-- renders a specific file -->

The file attribute must end in .md and may contain alphanumeric characters, hyphens, underscores, slashes, and dots.

Output is wrapped in <div class="s3md-content"> for CSS targeting.

Caching

Rendered HTML is cached as a WordPress transient (24-hour TTL). To force a refresh, use the Flush Markdown Cache button on the settings page.

The cache tracking is Redis-compatible — it stores transient keys in a separate option and deletes them individually rather than relying on database LIKE queries.

Security

• Markdown is rendered with Parsedown safe mode (all HTML in source markdown is escaped)
• File paths are validated with regex and checked for directory traversal
• Admin actions require manage_options capability and nonce verification
• AWS credentials are stored in wp_options and displayed as password fields

Dependencies

• Parsedown 1.7.4 (MIT, bundled)