In previous implementation ENV values were read only if config filepath is
specified. From now ENVs are always read to `Config`.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In some cases viper doesn't interpret `section.value` as a subsection with
`section` name, but value is value still can be accessed through full
pathname.
Fix `Config.Sub` method implementation in order to always interpret
configuration like described above as a subsection. From now method never
returns nil, therefore an additional check has been removed from the `Value`
method.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Create `config` package nearby storage node application. Implement `Config`
as a wrapper over `viper.Viper` that provides the minimum functionality
required by the application.
The constructor allows you to read the config from the file. Methods are
provided for reading subsections and values from the config tree. Helper
functions are implemented to cast a value to native Go types.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
