nginx and varnish for caching forcing ssl

Question

I'm in the process of doing my homework for a move from apache w/o caching to nginx with caching, possibly via varnish...

After reading various blogs, articles, serverfault questions, etc. I understand that varnish cannot work with ssl, and that varnish might be better than nginx for actual caching of dynamic content. But I'm a little stuck in understanding how nginx caching works AND how nginx+varnish can play together when ssl is required.

How would the following be implemented, with nginx+varnish OR just nginx with caching?

1. some urls driven by a custom php engine: i.e. example.com/this-page is served by example.com/index.php?p=this-page

2. some urls are driven by wordpress: i.e. example.com/blog/this-article is handled by wordpress via example.com/blog/index.php?p=this-article

3. should force ssl everywhere: i.e. http://example.com/* redirects to https://example.com/*

4. www should redirect to top domain: i.e. http://www.example.com/* redirects to https://example.com/*

All of which serving the cached version if it exists (if I understand- caching is time based, so if I make an update to that page, I need to call PURGE if the varnish route and manually delete files if the nginx route)

Answer 1

If you want to use nginx and Varnish I would suggest something like this.

• nginx as the frontend and SSL terminator, configured with Varnish as backend. This will also normalize (rewrite) hostnames from e.g. www.example.org to example.org.
• Varnish for caching content from its backend, nginx
• nginx with virtualhosts running on e.g. port 8080 with all "application logic" like WordPress-rewrites, custom PHP-engine rewrites and such.

So basically you would have a stack like this:

nginx -> Varnish -> nginx -> php-fpm

The four bullet points you mention would then be solved like this.

1. Backend-nginx with rewrites and proxy_pass to php-fpm.
2. Backend-nginx with WordPress-related rewrites.
3. Frontend-nginx with simple virtualhosts for redirections.
4. Same as 3.