Feature: nginx dynamic module support

Author: leev

README.md

@@ -7,7 +7,28 @@ Description
 First install [libmaxminddb](https://github.com/maxmind/libmaxminddb) as described in its [README.md
 file](https://github.com/maxmind/libmaxminddb/blob/master/README.md#installing-from-a-tarball).
 
-Compile nginx:
+#### Download nginx source
+```
+wget http://nginx.org/nginx-VERSION.tar.gz
+tar zxvf nginx-VERSION.tar.gz
+cd nginx-VERSION
+```
+
+##### To build as a dynamic module (nginx 1.9.11+):
+```
+./configure --add-dynamic-module=/path/to/ngx_http_geoip2_module
+make
+make install
+```
+
+This will produce ```objs/ngx_http_geoip2_module.so```. It can be copied to your nginx module path manually if you wish.
+
+Add the following line to your nginx.conf:
+```
+load_module modules/ngx_http_geoip2_module.so;
+```
+
+##### To build as a static module:
 ```
 ./configure --add-module=/path/to/ngx_http_geoip2_module
 make 
@@ -33,5 +54,37 @@ http {
         $geoip2_data_city_name default=London city names en;
     }
     ....
+
+    fastcgi_param COUNTRY_CODE $geoip2_data_country_code;
+    fastcgi_param COUNTRY_NAME $geoip2_data_country_name;
+    fastcgi_param CITY_NAME    $geoip2_data_city_name;
+    ....
 }
 ```
+
+To find the path of the data you want (eg: city names en), use the [mmdblookup tool](https://maxmind.github.io/libmaxminddb/mmdblookup.html):
+
+```
+$ mmdblookup --file /usr/share/GeoIP/GeoIP2-Country.mmdb --ip 8.8.8.8
+
+  {
+    "country": 
+      {
+        "geoname_id": 
+          6252001 <uint32>
+        "iso_code": 
+          "US" <utf8_string>
+        "names": 
+          {
+            "de": 
+              "USA" <utf8_string>
+            "en": 
+              "United States" <utf8_string>
+          }
+      }
+  }
+
+$ mmdblookup --file /usr/share/GeoIP/GeoIP2-Country.mmdb --ip 8.8.8.8 country names en
+
+  "United States" <utf8_string>
+```

config

@@ -7,9 +7,21 @@ ngx_feature_libs=-lmaxminddb
 
 if [ $ngx_found = yes ]; then
 	ngx_addon_name=ngx_http_geoip2_module
-	HTTP_MODULES="$HTTP_MODULES ngx_http_geoip2_module"
-	NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_http_geoip2_module.c"
-	CORE_LIBS="$CORE_LIBS -lmaxminddb"
+        module_src="$ngx_addon_dir/ngx_http_geoip2_module.c"
+
+	if test -n "$ngx_module_link"; then
+		ngx_module_type=HTTP
+		ngx_module_name="$ngx_addon_name"
+		ngx_module_incs=
+		ngx_module_deps=
+		ngx_module_srcs="$module_src"
+		ngx_module_libs="$ngx_feature_libs"
+		. auto/module
+	else
+		HTTP_MODULES="$HTTP_MODULES $ngx_addon_name"
+		NGX_ADDON_SRCS="$NGX_ADDON_SRCS $module_src"
+		CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+	fi
 else   
 	cat << END
 $0: error: the geoip2 module requires the maxminddb library.