geoip is a Go package that provides geoip information for an IP address, based on MaxMind GeoIP files, and a REST API, inspired from Telize.com, to get geoip information as a JSON structure.

All data are stored in memory for maximum speed. MaxMind files are automatically downloaded if the current files are older than 8 days. Initialization is made through init() and could take up to 30 seconds depending of your hardware configuration. Around 500MB of memory are required to store all geoip data.

• GeoLocIPv4() returns a GeoLocIp structure for a given IPv4 address.

• ServeHttpRequest() provides a REST API, returning a JSON structure holding the geolocation information for a given IPv4 address.

• ServeGeoLocAPI() starts a dedicated http server that only provides the REST API.

• MarshalJSON() implements the JSON Marshaler interface for the *GeoLocIp type.

Email to: kirabou (at) gmx.com

Error and information messages are written to the local system log (syslog).

• Currently works with IPv4 addresses only.

• Need to be restarted to reload GeoIP files from MaxMind.

Distributed under the MIT license.

• GeoIP data provided by MaxMind LLC.

• goggle/btree package used to store and search for data in memory.

The package can be installed using the following command : go get github.com/kirabu/geoip. It will install both the geoip package and the google/btree package.

The tests can be runned with go test github.com/kirabu/geoip. If you check your system log (/var/log/syslog), you'll see the main steps followed by geoip to download the MaxMind files and load them into memory :

Jan 25 05:43:35  geolocip[4204]: Starting
Jan 25 05:43:35  geolocip[4204]: Download http://download.maxmind.com/download/geoip/database/asnum/GeoIPASNum2.zip
Jan 25 05:43:37  geolocip[4204]: Extracted /tmp/GeoIPASNum2.csv
Jan 25 05:43:37  geolocip[4204]: Download http://geolite.maxmind.com/download/geoip/database/GeoLiteCity_CSV/GeoLiteCity-latest.zip
Jan 25 05:43:50  geolocip[4204]: Extracted /tmp/GeoLiteCity-Blocks.csv
Jan 25 05:43:51  geolocip[4204]: Extracted /tmp/GeoLiteCity-Location.csv
Jan 25 05:43:51  geolocip[4204]: Locations number of lines: 751379
Jan 25 05:43:55  geolocip[4204]: Locations file loaded
Jan 25 05:44:04  geolocip[4204]: Blocks file loaded
Jan 25 05:44:05  geolocip[4204]: ASN file loaded

The following example starts an http server, listening on the 9001 port. It returns a JSON structure with all the geoip information. For example :http://localhost:9001/54.88.55.63 returns the following JSON structure :

    { 
        "ip":"54.88.55.63",
        "country_code":"US",
        "region_code":"VA",
        "city":"Ashburn",
        "postal_code":"20147",
        "latitude":39.0335,
        "longitude":-77.4838,
        "metro_code":"511",
        "area_code":"703",
        "organization":"AS14618 Amazon.com, Inc.",
        "country":"États-Unis",
        "region":"Virginia" 
    }

Here the source code :

    package main
    
    import (
        "github.com/kirabou/geoip"
    )
    
    func main() {
        geolocip.ServeGeoLocAPI(9001)
    }

The next example is a simple forever loop, waiting for an IPv4 address, and returning the geoip information for it.

	package main

	import (
	    "github.com/kirabou/geoip"
	)

	func main() {

	    for {

			fmt.Print("Enter IPv4 address in a.b.c.d format : ")
			var ip_address string
	    	fmt.Scanf("%s", &ip_address)
			ip := net.ParseIP(ip_address)
			if ip == nil {
			    fmt.Println("Not a valid IP address.")
			    continue
			}

			fmt.Println(ip)
			json, _ := json.Marshal(geolocip.GeoLocIPv4(ip))

			fmt.Println(string(json))

	    }
	    
	}