在AppEngine上通过Golang进行Firebase

Question

I have a Firebase database that looks like this:

{
  "users" : [ null, {
    "name" : "John",
    "recipes" : {
      "34" : {
        "name" : "Chicken Parmesan"
      }
    }
  } ]
}

I'm trying to access the data through a Golang API. When I'm running the API locally, it works. However, when I try to use the API on AppEngine, Firebase returns null.

This is how I'm calling it:

userID := req.URL.Query().Get("user_id")

// Make call to API or to Database here, and then write out results
var user interface{}


f.Auth(<FIREBASE_SECRET>)


if err := f.Child("users/" + userID).Value(&user); err != nil {
    fmt.Print(w, err)
}

json.NewEncoder(w).Encode(user)

Any ideas on why this may not be working?