gogeo allows you you to access a GeoIP city database to determine Geographical information from an IP address.

• IPv4 support
• IPv6 support
• GeoRecord support
• Unlike other libraries, doesn't read the whole database into memory
• Fine grained control over database open modes, caching, etc.
• Works with go net.Addr's, which simplifies integration with go network programs.

• cgo based (not suitable for app engine deployments)

• Install libgeoip1 libgeoip-dev (on ubuntu)
• Download the geolite city database (either ipv4 or ipv6)
• go get -u github.com/shanemhansen/gogeo

• Look at the unit tests

package main
import "github.com/shanemhansen/gogeo"
import "net"
import "fmt"

func main() {
    db, err := gogeo.Open("/usr/share/GeoIP/GeoLiteCity.dat", gogeo.MemoryCache)
    if err != nil {
        panic(err)
    }
    addr, err := net.ResolveIPAddr("ip4", "google.com")
    record := db.RecordByIPAddr(addr)
    fmt.Printf("hello, from %s", record.CountryCode)
   }