nginx redirect multiple URLs with map

Question

I am trying to redirect a bunch of old URLs into new URls with the map directive. I am able to do the simple ones but kinda stuck on the ones with query parameters.

I need to do this

/people.php?personid=20 -> /people/20
/events.php/eventid=20 -> /event/20
/info.php?name=john&age=20 -> /person/john/20

I've got a map directive

map $request_uri $redirected_uri {
~^people.php\?personid=(.*)^ /people/$1?;
}

But doesn't seem to work. Any help would be appreciated. Thanks in advance.

My server block has this code

if ($redirected_uri) {
   rewrite  ^ $redirected_uri permanent;
}

Also, I am trying to do the following as well rewrite /people/20 back to people.php?personId=20 So, for that, I have this

map $request_uri $new_uri {
default 0
~^/people/(.*) /people.php?personId=$1;
}

and then in server block

if ($new_uri) {
rewrite ^ $new_uri last; // this doesn't work, throws 404
}

Answer 1

The common way to solve this looks something like this:

map $request_uri $redirect {
    default                          0;
    ~^/people.php\?personid=(\d+)^    /people/$1;
    ...
}

server {
    ...
    if ($redirect) {
        set $args '';
        return 301 $redirect;
    }

I have limited the capture group after personid= to digits: \d+

Answer 2

The numeric capture goes out of scope as soon as another regular expression is evaluated, so the rewrite statement itself wipes the value of $1 from the previous map statement.

You could use a return statement instead:

if ($redirected_uri) {
    return 301 $redirected_uri;
} 

Or better still, use a named capture in the map :

map $request_uri $redirected_uri {
~^/people\.php\?personid=(?<personid>.*)$ /people/$personid;
}

Note also that Nginx URIs begin with a leading / , you had an unescaped . , and the correct anchor for the end of a regular expression is $ .