Security – How to configure Apache to reject proxy requests with error code

I don't think that there is a way to explicitly invalidate cached items, but here is an example of how to do the rest. Update: As mentioned by Piotr in another answer, there is a cache purge module that you can use. You can also force a refresh of a cached item using nginx's proxy_cache_bypass - see Cherian's answer for more information.

In this configuration, items that aren't cached will be retrieved from example.net and stored. The cached versions will be served up to future clients until they are no longer valid (60 minutes).

Your Cache-Control and Expires HTTP headers will be honored, so if you want to explicitly set an expiration date, you can do that by setting the correct headers in whatever you are proxying to.

There are lots of parameters that you can tune - see the nginx Proxy module documentation for more information about all of this including details on the meaning of the different settings/parameters: http://nginx.org/r/proxy_cache_path

http {
  proxy_cache_path  /var/www/cache levels=1:2 keys_zone=my-cache:8m max_size=1000m inactive=600m;
  proxy_temp_path /var/www/cache/tmp; 


  server {
    location / {
      proxy_pass http://example.net;
      proxy_cache my-cache;
      proxy_cache_valid  200 302  60m;
      proxy_cache_valid  404      1m;
    }
  }
}

You'll need mod_ssl, mod_proxy and optionally mod_rewrite. Depending on your distribution and Apache version you may have to check if mod_proxy_connect and mod_proxy_http are loaded as well.

The directives for enabling SSL proxy support are in mod_ssl:

<VirtualHost 1.2.3.4:80>
    ServerName foo.com
    SSLProxyEngine On
    SSLProxyCheckPeerCN on
    SSLProxyCheckPeerExpire on
    ProxyPass / https://secure.bar.com
    ProxyPassReverse / https://secure.bar.com
</VirtualHost>

IIRC you can also use:

    RewriteRule / https://secure.bar.com [P]    # don't forget to setup SSLProxy* as well