[Feature Request] allow to override default name for environment variables

[mh-trimble]

I am writing an application copying an existing webservice, to stay sane I am structuring the config for my copy differently than the original service.

Most of the config I get from a toml file, but when I want to ship this to production I have to get api keys from environment variables that don't match the nested structure imposed by figment.

Is there a way to override the default (structured) names for environment variables like in this example taken from the envconfig crate

#[derive(Envconfig)]
struct Config {
    #[envconfig(from = "DB_HOST")]
    pub db_host: String,

    #[envconfig(from = "DB_PORT")]
    pub db_port: Option<u16>,

    #[envconfig(from = "HTTP_PORT", default = "8080")]
    pub http_port: u16,
}

[SergioBenitez]

I'm not quite sure I follow the question. Can you give a concrete example of what you're doing now, what doesn't work with it, and what you'd like to do? Alternatively, consider looking at https://serde.rs/field-attrs.html. Maybe alias or rename are what you want?

[mh-trimble]

Hey sure I'll try. The config I use is looking something like

host = "localhost"
port = 9000
[remote-service]
api_key = "dev-key"
...

#[derive(Debug, Deserialize, Clone)]
struct Config {
host: String,
port: u16,
remote_service: RemoteServiceConfig,
}

#[derive(Debug, Deserialize, Clone)]
struct RemoteService {
api_key: String
}

in production the environment variable to set/override is FOO_API_KEY instead of REMOTE_SERVICE__API_KEY - for historical reasons.

Is there a way (that I don't know) to set the name of the environment variable to deserialize the nested api_key?

[mh-trimble]

I hope this is a bit clearer

[mh-trimble]

I finally got around to testing the serde route and it worked - would you mind me adding a bit of documentation to help future users of the library (a.k.a. me in a month).

[SergioBenitez]

I finally got around to testing the serde route and it worked - would you mind me adding a bit of documentation to help future users of the library (a.k.a. me in a month).

Sure! What specifically might have helped you?