NGINX cache for Traefik

While Traefik is a really great and modern load-balancer, it does not support caching at the moment.

This project aims to solve that by putting Nginx, a caching load-balancer and reverse proxy in front of it.

This is written for Docker, but the nginx config can be applied to any configuration.

Features

Cache is stored and served entirely from memory
Returns stale items (and refreshes it), so cached content is always returned
Only static assets are cached... does not affect changing content like API queries
HTTP errors like 404 are not cached.

Nginx config can be found in the ./nginx folder.

Usage

Using Docker Compose:

docker compose up -d

Or alternatively, apply nginx.conf to your configuration.

Persistent caching

To persist the cache across nginx container restarts or system reboots:

Remove the shm_size line from docker-compose.yml
Mount a folder to store caching data, for example:

mkdir nginx-cache

...
  volumes:
    - ./nginx:/etc/nginx/conf.d:ro
    - ./nginx-cache:/cache

Change /dev/shm in the first line in nginx.conf to /cache, per the example above.
Run docker compose up -d or restart nginx

Test caching

To check whether an item is cached or not, check the X-Cache-Status header in response headers.

Here's an example with curl:

~> curl -s -I "http://10.0.0.99/login.html" | grep Cache
X-Cache-Status: MISS

~> curl -s -I "http://10.0.0.99/login.html" | grep Cache
X-Cache-Status: HIT

To-do