Beginnings of Go web server with mongoDb

Question

I am just learning how to use go and I'm a bit confused on how my code is supposed to be organised package wise.

Am I right to have the user package? I'm planning to redirect my /user/ routes to a handler in this package but I'm unsure if this is the go way to do things

My directory structure is

/go_rest_api
 /user
 -user.go
 -user_provider.go
 -app.go
 -main.go

main.go

package main
func main() {
 a := App{}
 a.Initialize()
 a.Run()
}

app.go

package main
import (
 "fmt"
 "log"
 "github.com/gorilla/mux"
 "gopkg.in/mgo.v2"
 "go_rest_api/user"
)
type App struct {
 Router *mux.Router
 Mongo *MongoConnection
}
type MongoConnection struct {
 Session *mgo.Session
}
func(a* App) GetMongoSession() *mgo.Session {
 return a.Mongo.Session.Copy()
}
func(a *App) Initialize() {
 session, err := mgo.Dial("127.0.0.1:27017")
 if err != nil {
 panic(err)
 }
 session.SetMode(mgo.Monotonic, true)
 a.Mongo = &MongoConnection{session}
 a.Router = mux.NewRouter()
}
func(a *App) Run() {
 defer a.Mongo.Session.Close()
 testMongo(a.GetMongoSession())
}
func testMongo(session *mgo.Session) {
 userProvider := user.Provider(session)
 err := userProvider.InsertUser(user.User{"test"})
 if err != nil {
 log.Fatal(err)
 }
 user := user.User{}
 err, user = userProvider.GetUser("test")
 if err != nil {
 log.Fatal(err)
 }
 fmt.Println("username:", user.Username)
}

user/user.go

package user
type User struct {
 Username string
}

user/user_provider.go

package user
import (
 "gopkg.in/mgo.v2/bson"
 "gopkg.in/mgo.v2"
)
type provider struct {
 Collection *mgo.Collection
}
func Provider(mongoSession *mgo.Session) provider {
 p := provider{}
 p.Collection = mongoSession.DB("test").C("user")
 return p
}
func(p *provider) InsertUser(user User) error {
 return p.Collection.Insert(&user)
}
func (p *provider) GetUser(username string) (error, User) {
 result := User{}
 err := p.Collection.Find(bson.M{"username": username}).One(&result)
 return err, result
}

• ferada: Welcome to Code Review, your first post looks good, you should get some good answers!

Answer 1

You might wanted to start writing some comments on your code.

For example I've read all your code but there are some method that I don't understand like :

func(a* App) GetMongoSession() *mgo.Session {
 return a.Mongo.Session.Copy()
}

Okay we know It is getting the mongo session. but for what purpose?

// We get the mongo session for .... you can start explain why
func(a* App) GetMongoSession() *mgo.Session {
 return a.Mongo.Session.Copy()
}

I think it is a good think to keep comment the code, so others can understand it quickly. especially when someone who new to mongoDB. :D