The `godotenv` package

The godotenv package

The godotenv package in Go is commonly used for loading environment variables from a .env file into the application’s environment. Here are the most used functions of the godotenv package:

1. godotenv.Load()

   • This function loads environment variables from a .env file into the process environment. It returns an error if it fails to load the file.

   err := godotenv.Load()
   if err != nil {
       log.Fatal("Error loading .env file")
   }

2. godotenv.Load(filenames ...string)

   • This function allows you to specify custom file names instead of just .env. You can pass multiple filenames, and it will load them in the given order.

   err := godotenv.Load(".env.local", ".env")
   if err != nil {
       log.Fatal("Error loading .env files")
   }

3. godotenv.Overload()

   • Similar to Load(), but it will overwrite any existing environment variables with those from the .env file.

   err := godotenv.Overload()
   if err != nil {
       log.Fatal("Error loading .env file and overwriting existing environment variables")
   }

4. godotenv.Overload(filenames ...string)

   • This is the overloaded version that accepts custom filenames to load environment variables from specific files while overwriting existing variables.

   err := godotenv.Overload(".env.local", ".env")
   if err != nil {
       log.Fatal("Error loading .env files with overwrite")
   }

5. godotenv.Parse()

   • This function is used to manually parse environment variables from a .env file into a map. It’s useful when you want to load the contents of a file without actually modifying the environment.

   envs, err := godotenv.Parse(".env")
   if err != nil {
       log.Fatal("Error parsing .env file")
   }
   fmt.Println(envs) // Map of environment variables

6. godotenv.MustLoad()

   • This function loads environment variables from a .env file, but it panics if the file can’t be loaded, making it less suitable for situations where you need error handling.

   godotenv.MustLoad() // Panics if the .env file is not found

These functions allow you to configure and manage environment variables in a Go application seamlessly, ensuring they are loaded and accessible throughout the program.