I enjoy the wordpress autoupdates or plugins, themes and core however when I moved a blog to an ubuntu server it kept asking me for the ftp details (which I did not have). So after a bit of looking around and reading up the simplest solution was to change the whole directory to have the owner www-data and group www-data.
To do this SSH in, navigate to the folder above the web directory public folder (in my case public_html) and type the following:
sudo chown -R www-data:www-data public_html