using Environment source to get List of struct

[Gaelik-git]

Hello I would like to know if it's actually possible to have this Settings::new return a Ok result

use config::{Config, ConfigError, Environment};
use serde::Deserialize;

#[derive(Debug, Deserialize)]
#[allow(unused)]
struct Auth {
    token: String,
    secret: String,
}

#[derive(Debug, Deserialize)]
#[allow(unused)]
pub struct Settings {
    auths: Vec<Auth>,
}

impl Settings {
    pub fn new() -> Result<Self, ConfigError> {
        let s = Config::builder()
            .add_source(
                Environment::with_prefix("APP")
                    .separator("_")
                    .try_parsing(true),
            )
            .build()?;

        s.try_deserialize()
    }
}

fn main() {
    let settings = Settings::new();

    // Print out our settings
    println!("{:?}", settings);
}

I was thinking something like APP_AUTHS_0_TOKEN=token APP_AUTHS_0_SECRET=secret cargo run
I found the list_separator method on Environment but I think it's only to manage Vec<String>

Is it something that is currently possible ? If not is it a feature that would make sense to implement or maybe I should use another Source ?

Thanks

[matthiasbeyer]

Hi, I think something like that is not possible right now.

[momvart]

It would be great to have support for this. Also, the convention that the OP has used is employed in ASP.Net as well.

[0xForerunner]

+1 on this!

[epage]

git puts the index in a weird spot but they also require a _COUNT variable

From https://git-scm.com/docs/git-config#ENVIRONMENT

GIT_CONFIG_COUNT
GIT_CONFIG_KEY_<n>
GIT_CONFIG_VALUE_<n>

If GIT_CONFIG_COUNT is set to a positive number, all environment pairs GIT_CONFIG_KEY_<n> and GIT_CONFIG_VALUE_<n> up to that number will be added to the process’s runtime configuration. The config pairs are zero-indexed. Any missing key or value is treated as an error. An empty GIT_CONFIG_COUNT is treated the same as GIT_CONFIG_COUNT=0, namely no pairs are processed. These environment variables will override values in configuration files, but will be overridden by any explicit options passed via git -c.

This is useful for cases where you want to spawn multiple git commands with a common configuration but cannot depend on a configuration file, for example when writing scripts.

[weyert]

Wouldn’t the reason of _COUNT already being mentioned above?

This is useful for cases where you want to spawn multiple git commands with a common configuration but cannot depend on a configuration file, for example when writing scripts.