How to write NGINX Url proxy?

Question

I want to convert the url

https://example.com/?city=FLorida&type=America&date=2019-06-06-15:15

to

https://example.com/Florida/America/06-june-2019-1515

Use nginx as a proxy to serve the first url when user request the second url.

Answer 1

The difficulty is translating the month names into numbers, which is solved using a map with 12 regular expressions. See this document for details.

The first example does everything in the map. I have used a redirect to test it, as I don't know how you intend to process the rewritten URI internally.

map $uri $newuri {
    default  0;
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-jan(uary)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
       "/?city=$city&type=$type&date=$year-01-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-feb(ruary)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-02-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-mar(ch)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-03-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-apr(il)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-04-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-may-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-05-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-june?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-06-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-july?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-07-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-aug(ust)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-08-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-sep(tember)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-09-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-oct(ober)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-10-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-nov(ember)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-11-$day $hour:$min";
    ~*^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-dec(ember)?-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$
        "/?city=$city&type=$type&date=$year-12-$day $hour:$min";
}

server {
    ...
    if ($newuri) { return 302 $newuri; }
    ...
}

---

Alternatively, just using the map to translate the month names:

map $month $month_num {
    ~*^jan(uary)?$          "01";
    ~*^feb(ruary)?$         "02";
    ~*^mar(ch)?$            "03";
    ~*^apr(il)?$            "04";
    ~*^may$                 "05";
    ~*^june?$               "06";
    ~*^july?$               "07";
    ~*^aug(ust)?$           "08";
    ~*^sep(tember)?$        "09";
    ~*^oct(ober)?$          "10";
    ~*^nov(ember)?$         "11";
    ~*^dec(ember)?$         "12";
}

server {
    ...
    if ($uri ~* ^/(?<city>\w+)/(?<type>\w+)/(?<day>\d\d)-(?<month>\w+)-(?<year>\d\d\d\d)-(?<hour>\d\d)(?<min>\d\d)$)
    {
        return 302 "/?city=$city&type=$type&date=$year-$month_num-$day $hour:$min";
    }
    ...
}

See this caution on the use of if.