geofence

go-geofence

A small library to detect if an IP address is close to yours or another of your choosing using https://ipbase.com/

Usage

First you will need a free API Token from ipbase.com

go get github.com/circa10a/go-geofence

package main

import (
	"fmt"
	"log"
	"time"

	"github.com/circa10a/go-geofence"
)

func main() {
	geofence, err := geofence.New(&geofence.Config{
		// Empty string to geofence your current public IP address, or you can monitor a remote address by supplying it as the first parameter
		IPAddress: "",
		// ipbase.com API token
		Token: "YOUR_IPBASE_API_TOKEN",
		// Maximum radius of the geofence in kilometers, only clients less than or equal to this distance will return true with IsIPAddressNear()
		// 1 kilometer
		Radius: 1.0,
		// Allow 192.X, 172.X, 10.X and loopback addresses
		AllowPrivateIPAddresses: true,
		// How long to cache if any ip address is nearby
		CacheTTL: 7 * (24 * time.Hour), // 1 week
	})
	if err != nil {
		log.Fatal(err)
	}
	isAddressNearby, err := geofence.IsIPAddressNear("8.8.8.8")
	if err != nil {
		log.Fatal(err)
	}
	// Address nearby: false
	fmt.Println("Address nearby: ", isAddressNearby)
}

Caching

To cache keys indefinitely, set CacheTTL: -1

Local (in-memory)

By default, the library will use an in-memory cache that will be used to reduce the number of calls to ipbase.com and increase performance. If no CacheTTL value is set (0), the in-memory cache is disabled.

Persistent

If you need a persistent cache to live outside of your application, Redis is supported by this library. To have the library cache address proximity using a Redis instance, simply provide a RedisOptions struct using the cache package to geofence.Config.RedisOptions. If RedisOptions is configured, the in-memory cache will not be used.

Note: Only Redis 7 is currently supported at the time of this writing.

Example Redis Usage

package main

import (
	"fmt"
	"log"
	"time"

	"github.com/circa10a/go-geofence"
	geofencecache "github.com/circa10a/go-geofence/cache"
)

func main() {
	geofence, err := geofence.New(&geofence.Config{
		IPAddress: "",
		Token: "YOUR_IPBASE_API_TOKEN",
		Radius: 1.0,
		AllowPrivateIPAddresses: true,
		CacheTTL: 7 * (24 * time.Hour), // 1 week
		// Use Redis for caching
		RedisOptions: &geofencecache.RedisOptions{
			Addr:     "localhost:6379",
			Username: "", // no username set
			Password: "", // no password set
			DB:       0,  // use default DB
		},
	})
	if err != nil {
		log.Fatal(err)
	}
	isAddressNearby, err := geofence.IsIPAddressNear("8.8.8.8")
	if err != nil {
		log.Fatal(err)
	}

	// Address nearby: false
	fmt.Println("Address nearby: ", isAddressNearby)
}