Add the following line at the bottom of your config/environment.rb
Redmine::Utils::relative_url_root = "/redmine"
Start the thin server with --prefix /redmine
, in my case:
thin start --prefix "/redmine" -s1 --socket /tmp/thin.sock
Change your nginx configuration to:
location /redmine {
proxy_pass http://redmine/redmine;
}
Also look at the documentation.