envy

Envy makes working with ENV variables in Go trivial.

• Get ENV variables with default values.
• Set ENV variables safely without affecting the underlying system.
• Temporarily change ENV vars; useful for testing.
• Map all of the key/values in the ENV.
• Loads .env files (by using godotenv)
• More!

Installation

$ go get -u github.com/gobuffalo/envy

Usage

func Test_Get(t *testing.T) {
	r := require.New(t)
	r.NotZero(os.Getenv("GOPATH"))
	r.Equal(os.Getenv("GOPATH"), envy.Get("GOPATH", "foo"))
	r.Equal("bar", envy.Get("IDONTEXIST", "bar"))
}

func Test_MustGet(t *testing.T) {
	r := require.New(t)
	r.NotZero(os.Getenv("GOPATH"))
	v, err := envy.MustGet("GOPATH")
	r.NoError(err)
	r.Equal(os.Getenv("GOPATH"), v)

	_, err = envy.MustGet("IDONTEXIST")
	r.Error(err)
}

func Test_Set(t *testing.T) {
	r := require.New(t)
	_, err := envy.MustGet("FOO")
	r.Error(err)

	envy.Set("FOO", "foo")
	r.Equal("foo", envy.Get("FOO", "bar"))
}

func Test_Temp(t *testing.T) {
	r := require.New(t)

	_, err := envy.MustGet("BAR")
	r.Error(err)

	envy.Temp(func() {
		envy.Set("BAR", "foo")
		r.Equal("foo", envy.Get("BAR", "bar"))
		_, err = envy.MustGet("BAR")
		r.NoError(err)
	})

	_, err = envy.MustGet("BAR")
	r.Error(err)
}

.env files support

NOTE: the behavior of .env support was changed in v2. Previously, envy.Load() overwrote all pre-existing environment variables with the values in the .env file but now pre-existing variables have higher priority and will remain as is. (It will help you to configure your runtime environment in the modern platforms including cloud computing environments)

Envy now supports loading .env files by using the godotenv library. That means one can use and define multiple .env files which will be loaded on-demand. By default, Envy loads .env file in the working directory if the file exists. To load additional one or more, you need to call the envy.Load function in one of the following ways:

envy.Load() // 1

envy.Load("MY_ENV_FILE") // 2

envy.Load(".env.prod", ".env") // 3

envy.Load(".env", "NON_EXISTING_FILE") // 4

envy.Load(".env.prod", "NON_EXISTING_FILE", ".env") // 5

// 6
envy.Load(".env.prod")
envy.Load("NON_EXISTING_FILE")
envy.Load(".env")

1. Will load the default .env file from the current working directory.
2. Will load the file MY_ENV_FILE, but not .env
3. Will load the file .env.prod first, then will load the .env file. If any variable is redefined in .env, they will be ignored.
4. Will load the .env file and return an error as the second file does not exist. The values in .env will be loaded and available.
5. Will load the .env.prod file and return an error as the second file does not exist. The values in .env.prod will be loaded and available, but the ones in .env won't.
6. The result of this will be the same as 3 as you expected.