nginx "starts with" regex

Question

I'm trying to block/allow access to a particular vhost based on string matching of the HTTP user agent name.

The version number of the application in the HTTP user agent changes, e.g.

My%20App/1.55.01 CFNetwork/711.5.6 Darwin/14.0.0 My%20App/1.49.03 CFNetwork/711.5.6 Darwin/14.0.0 My%20App/1.35.02 CFNetwork/711.5.6 Darwin/14.0.0 

I want to match everything starting with My%20App/ - anything that matches should be allowed access, anything else should get HTTP 403.

I don't want to have to update the nginx config every time a new version of the app comes along.

The following works fine:

if ($http_user_agent !~* "My%20App/1.55.01 CFNetwork/711.5.6 Darwin/14.0.0") { return 403; } 

I figure I need a solution that involves hat (^) for "starts with" but I can't get nginx to accept anything I've tried.

Thanks in advance.

Answer 1

Turns out that the following works.

if ($http_user_agent !~* "My%20App/*") { return 403; }