For a Python / Django application running on cloudcontrol, what's the recommended way of rewriting urls, e.g. attaching a wordpress blog to a certain url path like example.com/blog/, or even just redirecting a subdomain?
I'd know how to do this with an .htaccess file - is there an equivalent that would work on cloudcontrol? I found some sample cctrl apps that use .htaccess files (e.g. https://github.com/cloudControl/example_apps/blob/master/php/kohana/example.htaccess), but that's all PHP and it does not seem to work for my Django app.
You have multiple options. Let me explain the basic concept first. Generally every app on cloudControl has its own subdomain like APP_NAME.cloudcontrolled.com. Requests to those subdomains (or from a CNAME pointing to that subdomain) are forwarded by the routing tier to one or more of the containers available to serve requests. What runs inside each container is controlled by the Buildpack. Depending on the preferences of each language ecosystem (e.g. PHP vs Python) the runtime environment in the container differs. So for PHP, Apache is available while for Python it is not.
Option 1: The recommended way would be to have e.g. www.example.com poing to PYTHON_APP.cloudcontrolled.com and blog.example.com point to PHP_APP.cloudcontrolled.com.
Option 2: Alternatively if you have to use /blog instead of a blog. subdomain you can teach the Apache running inside the PHP App's containers to only serve requests for /blog and forward everything else to PYTHON_APP.cloudcontrolled.com.
Option 3: Soon you'd have a third option also, but this isn't available yet. We're currently working on enabling the Python buildpack to run Nginx inside the containers and use WSGI to communicate with the Python process. (Currently the Python process has to listen on the $PORT and serve HTTP directly) As soon as Nginx is available you could also configure it to forward /blog to PHP_APP.cloudcontrolled.com and serve everything else directly.
My recommendation would be to go with option 1, since that keeps both apps nicely decoupled. By permanently redirecting /blog in the Python app to blog.example.com you can make the migration painless.