What is this for?

Read Configurations from different sources

How to use it

Read configuration from flags

To load flags into your configuration struct, just indicate the name of the flag with the flag tag, flag-usage is optional

type Conf struct {
    Field string    `flag:"flag-for-field" flag-usage:"not important"`
}

...
var conf Conf
if err := gonphig.ReadConfig(&conf); err != nil {
	log.Fatal(err)

Gonphig will take care of the flag declaration and the flag.Parse() for you when it reads the configuration

Read configuration from ENV variables

To load env-var into your configuration struct, just indicate the name of the variable with the env tag

type Conf struct {
   Field string     `env:"env_variable_to_read"`
}

...
var conf Conf
if err := gonphig.ReadConfig(&conf); err != nil {
	log.Fatal(err)
}

Assign default values

You can add a default value to your configuration using the default tag

type Conf struct {
   Field string     `default:"someValue"`
   AnInt int        `default:"42"`
}

Read configurations from a YAML file

The values provided on the file will be taken as the default values

type Conf struct {
    Field string 
}
...
var conf Conf
if err := gonphig.ReadFromFile("path/to/file.yml", &conf); err != nil {
	log.Fatal(err)
}

If you want to rename a field in the yaml file and map it into your config struct, you can use the yaml tag

type Conf struct {
    NotTheSameName string `yaml:"field"`
}

Validation

It is possible to add validations over the configuration values using the validate tag

type Conf struct {
   Field string `env:"env_variable_to_read" validate:"required"`
}

Configuration hierarchy

1. Configuration read from flags
2. Configuration read from env-var
3. Configuration coming from the default tag
4. Configuration read from the yaml file

External resources

YAML

• SPEC
• To read the YAML file we are using an external library. All information can be found here

Validations

• To perform validations on the configuration struct, We are using an external library. All information can be found here