> Hence I have to place nginx before apache without disturbing the
> setup.
>

works seemlessly and speeds up your apache, when using proxy_cache, assuming your
apache listens on 8080


server {
listen 80;
server_name myhost;
location / {
root /path/to/myapp/public;
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://apache:8080;
}
}

from this basic snippet you can go on and test different setups
with additional nginx-virtualhosts before making changes work in your prod-environment


server {
# this is for testing new setups
listen 81;
server_name myhost;
location / {
root /path/to/myapp/public;
proxy_cache cache;
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://apache:8080;
}
}