How to clear the nginx static cache

This is how you clear the nginx fastcgi cache or proxy cache.

First, find the path to your static cache files. In your nginx config, you should have a fastcgi_cache_path or proxy_cache_path set. For example, this is mine:

# /etc/nginx/nginx.conf
fastcgi_cache_path /var/run/nginx-cache/craftcache levels=1:2 keys_zone=craftcache:100m [...];

My static cache path is /var/run/nginx-cache/craftcache. To clear the static cache, I must delete the contents of this directory, but not the directory itself:

# Correct - this deletes the cache files, but not the cache directory
rm -rf /var/run/nginx-cache/craftcache/*

# Wrong - this deletes the cache directory and requires an nginx restart
rm -rf /var/run/nginx-cache/craftcache

Clearing the nginx cache inside docker

If you run nginx inside docker, the wildcard is interpreted on the host, not inside the container. It will not delete any files. You must do it this way:

# Correct - this will clear the cache
docker-compose exec your_nginx_container sh -c 'rm -rf /var/run/nginx-cache/craftcache/*';

# Wrong - this will not delete any files
docker-compose exec your_nginx_container rm -rf /var/run/nginx-cache/craftcache/*;

tl;dr

rm -rf /var/run/nginx-cache/craftcache/*