Serve different files for specific user agents using nginx

Question

Using nginx, how do you serve different static files for different user agents? For example, if the current user is using an iPhone, they should be served mobile_index.html, whereas all other user agents should be served browser_index.html.

Found solution:

server {
  listen 80;
  root /var/www;

  set $mobile_request '0';
  if ($http_user_agent ~ 'iPhone') {
    set $mobile_request '1';
  }

  location =/ {
    if ($mobile_request = '1') {
      rewrite ^ /mobile_index.html;
    }
    if ($mobile_request = '0') {
      rewrite ^ /browser_index.html;
    }
  }
}

Answer 1

If you have a new enough version of nginx (0.9.6+), you could accomplish this with a map:

map $http_user_agent $myindex {
  default /browser_index.html;
  ~iPhone /mobile_index.html;
}

server {
  listen 80;
  root /var/www;

  location = / { rewrite ^ $myindex; }
}

If you don't need an internal redirect (which you probably don't if you're just serving static files for the indexes), you could add a 'break' flag to the rewrite and avoid the internal redirect.

EDIT: If you're using an older version, you could do something like this:

server {
  listen 80;
  root /var/www;

  location = / {
    set $myindex /browser_index.html;
    if ($http_user_agent ~ iPhone) {
      set $myindex /mobile_index.html;
    }
    rewrite ^ $myindex;
  }
}

again, using the break flag if you don't need the internal redirect.