genhttp/local-mirror repository overview

⁠Local Mirror

Docker service to create a network-local mirror of a remote server providing files via HTTP.

⁠Features

• Caches responses of an upstream server on local disc or in memory
• Serves more than 100k of requests per second, depending on the size
• Simple setup, just pass the upstream URL
• Enables zstd, br and gzip compression with maximum compression level
• Enables download progress (by sending a Content-Length)
• Enables download resumption (via range requests)
• Enables client-side caching (via eTag)

⁠Out of scope

• No cache invalidation or expiration (a file will always be served once fetched from the upstream)
• TLS is not supported and should be terminated by some reverse proxy in front

⁠Usage

Basic usage:

docker run -d -p 8080:8080 -e TARGET=https://cdn.jsdelivr.net/npm/ genhttp/local-mirror

wget http://localhost:8080/jquery/dist/jquery.min.js

Docker compose syntax:

services:
  mirror:
    image: genhttp/local-mirror
    ports:
      - "8080:8080"
    environment:
      - TARGET=https://cdn.jsdelivr.net/npm/
      - CACHE_MODE=persistent # or memory

⁠Cache Modes

By default, the service will store all responses in /app/cache/. You can mount this path as a volume to keep the cache when re-creating the container.

Setting CACHE_MODE to memory will keep all objects in memory until the container is restarted. There is no memory limit applied so this mode should only be used in a safe environment where we know how big the cache might grow.