environ

Load environement variables without the hustle.

type Envs struct {
	Url    string `env:"name=URL, type=url, default=http://localhost"`
	Port   int    `env:"name=PORT, type=port, default=8080"`
}

envs, err := environ.Load[Envs]()

envs.Url  // http://localhost
envs.Port // 8080

Installation

go get github.com/AnatoleLucet/environ

Usage

With environ, you can load environments variables in three ways.

There's no good or bad option here. environ wants to provide a way to load environment variables for you as simply and flexibly as possible in any situation, without any compromise. So pick the one that makes most sense for you!

Tag-based loading

type Envs struct {
    Url      string `env:"name=URL, type=url, default=http://localhost"`
    Port     int    `env:"name=PORT, type=port, optional"`
    Secret   string `env:"name=SECRET, type=string"`
}

func LoadEnvs() {
    envs, err := environ.Load[Envs]()
    // or with panic:
    // envs := environ.MustLoad[Envs]()
}

Builder-based loading

func LoadEnvs() {
    url, err := environ.Url("URL").Default("http://localhost").Load()
    port, err := environ.Port("PORT").Optional().Load()
    secret, err := environ.String("SECRET").Load()
    // or with panic:
    // secret := environ.String("SECRET").MustLoad()
}

Struct-based loading

func LoadEnvs() {
    defaultUrl := "http://localhost"

    url, err := environ.Variable[string]{
        Name: "URL",
        Type: environ.TypeUrl,
        Default: &defaultUrl,
    }.Load()
    port, err := environ.Variable[int]{
        Name: "PORT",
        Type: environ.TypePort,
        Optional: true,
    }.Load()
    secret, err := environ.Variable[string]{
        Name: "SECRET",
        Type: environ.TypeString,
    }.Load()
    // or with panic:
    // secret := environ.Variable[string]{Name: "SECRET", Type: environ.TypeString}.MustLoad()
}

Options

Name	Go Type	Description	Tag Example
name	string	Name of the environment variable to load	env="name=URL"
type	VariableType	Expected type of the variable's value	env="type=bool"
default	T	Fallback value if the variable is not defined	env="default=http://localhost"
optional	bool	If the variable is allowed to be empty of not	env="optional"
desc	string	Description of the variable	env="desc=A short description about this variable"
oneof	[]T	Allow-list of values the variable can be set to	env="oneof=80|3000|8080"

Variable Types

Type	Go Type	Description	Tag Example
TypeString	string	Any string value	env:"type=string"
TypeInt	int	Integer number	env:"type=int"
TypeFloat	float64	Floating point number	env:"type=float"
TypeBoolean	bool	Boolean value (accepts: true, false, 0, 1, on, off)	env:"type=bool"
TypePort	int	Valid TCP port number (1-65535)	env:"type=port"
TypeUrl	string	Valid URL with protocol and hostname	env:"type=url"
TypeEmail	string	Valid email address	env:"type=email"