A Traefik middleware plugin that automatically generates and propagates correlation IDs across requests using UUID v7.

• Automatic UUID v7 Generation — Generates a unique correlation ID for each request if one doesn't already exist
• Header Pass-through — Preserves existing correlation IDs from upstream services
• Configurable Header Name — Customize the header name (defaults to X-Klz-Correlation-Id)
• Zero Dependencies — Uses only the standard library and Google's UUID library

Add the plugin to your Traefik configuration.

http:
  middlewares:
    correlation-id:
      plugin:
        correlation-id:
          headerName: X-Klz-Correlation-Id  # Optional, defaults to X-Klz-Correlation-Id

Apply the middleware to a route or service:

http:
  routers:
    my-router:
      rule: Path(`/api`)
      middlewares:
        - correlation-id
      service: my-service

1. If the request already has a correlation ID header, it is preserved and passed downstream
2. If no correlation ID exists, a new UUID v7 is generated and added to the request
3. The middleware passes the request (with the correlation ID) to the next handler

Version 7 UUIDs use:

• A timestamp component (better sortability)
• A counter for monotonicity
• Cryptographic randomness

This provides better entropy and sorting properties compared to v1 UUIDs.