storelocator with golang and mongodb

Hey i am trying to build a store-locator using golang and mongodb .
I am new to both . I tried to search but was not able to find a code in golang which can help me insert store with name and co-ordinates into mongodb and then search for stores in a radius of 3000 meters of provided latitude and longitude value .

Note : i want to provide id by myself so that i can easily fetch stores if i have the id .

I tried as given below but nothing happens , no error or store insertion in db

test.go is as below :

package main
import (
"encoding/json"
"fmt"
"gopkg.in/mgo.v2"
"gopkg.in/mgo.v2/bson"
"log"
)
type Store struct {
ID       string  `bson:"_id,omitempty" json:"shopid"`
Name     string  `bson:"name" json:"name"`
Location GeoJson `bson:"location" json:"location"`
}
type GeoJson struct {
Type        string    `json:"-"`
Coordinates []float64 `json:"coordinates"`
}
func main() {
cluster := "localhost" // mongodb host
// connect to mongo
session, err := mgo.Dial(cluster)
if err != nil {
log.Fatal("could not connect to db: ", err)
panic(err)
}
defer session.Close()
session.SetMode(mgo.Monotonic, true)
// search criteria
long := 39.70
lat := 35.69
scope := 3000 // max distance in metres
var results []Store // to hold the results
// query the database
c := session.DB("test").C("stores")
// insert
man := Store{}
man.ID = "1"
man.Name = "vinka medical store"
man.Location.Type = "Point"
man.Location.Coordinates = []float64{lat, long}
// insert
err = c.Insert(man)
fmt.Printf("%v\n", man)
if err != nil {
fmt.Println("There is insert error")
panic(err)
}
// ensure
// Creating the indexes
index := mgo.Index{
Key:  []string{"$2dsphere:location"},
Bits: 26,
}
err = c.EnsureIndex(index)
if err != nil {
fmt.Println("There is index error")
panic(err)
}
//find
err = c.Find(bson.M{
"location": bson.M{
"$nearSphere": bson.M{
"$geometry": bson.M{
"type":        "Point",
"coordinates": []float64{long, lat},
},
"$maxDistance": scope,
},
},
}).All(&results)
//err = c.Find(bson.M{"_id": "1"}).All(&results)
if err != nil {
panic(err)
}
//convert it to JSON so it can be displayed
formatter := json.MarshalIndent
response, err := formatter(results, " ", "   ")
fmt.Println(string(response))
}

@user7227958

Looks like Go is playing tricks with you due to (lack of) float64 preciseness of your coordinates.

Check this:
with long := 39.70 and lat := 35.69 you need a scope=3000000 for your record to be selected.
However if you'll use more precise coordinates, say

long := 39.6910592
lat := 35.6909623

then you'll be able to find your store even with a scope of 1 meter (which is expected).

Cheers,
-D