How to use constant across go package - go

Question

I'm writing my first go code and I'm trying to convince myself what I'm doing is not wrong.
anyway, here the project the tree structure.
.
├── helpers
│   └── common.go
├── logger
│   └── util.go
├── logger_example
└── runner.go
The main file to look over here is logger/util.go which look like this.
package logger
import (
"log"
"os"
)
type Logger struct {
*log.Logger
}
func (l *Logger) Info(v ...interface{}) {
l.SetPrefix("Info: ")
l.Println(v...)
}
func (l *Logger) Error(v ...interface{}) {
l.SetPrefix("Error: ")
l.Println(v...)
}
func (l *Logger) Warn(v ...interface{}) {
l.SetPrefix("Warn: ")
l.Println(v...)
}
func (l *Logger) Debug(v ...interface{}) {
l.SetPrefix("Debug: ")
l.Println(v...)
}
func NewLogger() *Logger {
logger := log.New(os.Stdout, "", log.Ldate|log.Ltime|log.Lshortfile)
return &Logger{logger}
}
As you all can see, I'm just setting the prefix to "INFO | WARN | ERROR | DEBUG"
On the main package I have safely created a Logger instance and VOILA it worked.
Only until I decided to add a helpers package and now things do not look the way I wanted.
since the logger.Logger instance created inside main package, I have to pass it reference to every since package function where I want to invoke the logger statement. (see the below example ..)
// dodly_logger/logger/common.go
package helpers
import "dodly_logger/logger"
func Display(dodlyLogger *logger.Logger) {
dodlyLogger.Info("Inside a helper package")
}
The Main package..
package main
import (
logger "dodly_logger/logger"
helpers "dodly_logger/helpers"
)
func main() {
dodlyLogger := logger.NewLogger()
dodlyLogger.Info("INFO MESSAGE")
dodlyLogger.Error("ERROR MESSAGE")
// Ehh, I have to pass the dodlyLogger ..
helpers.Display(dodlyLogger)
}
Ok, now I know my GOLang knowledge is not complete hence I'm hoping people over here can point me how can I write this more clinically wherein I do not have to pass the reference of the logger.Logger to every function for which I need to log.

Answer 1

Create a package level variable with var.
package main
import (
logger "dodly_logger/logger"
helpers "dodly_logger/helpers"
)
var dlogger logger.Logger
func init() {
dlogger = logger.NewLogger()
}
func main() {
dlogger.Info("Starting Main")
a()
}
func a() {
dlogger.Info("in a")
}