Picking up values from environment not working

[algermissen]

Hi,

I am trying to use the environment only, to grep the configuration. Because that did not work, I also tried with an additional Settings.toml. Then the value from file is picked up, but not the environment.

Code:

let mut settings = config::Config::default();
settings
   .merge(config::File::with_name("Settings"))
    .unwrap()
    .merge(config::Environment::with_prefix("APP"))
    .unwrap();

let x = settings.get::<String>("foo").expect("ok");
println!("CFG: {:?}", x);

Settings.toml:
foo = "20"

Calling the program with APP_FOO=10 target/debug/prog. Only the value from toml is picked up.

I must be doing something very stupid, but I cannot get this to work. Can you spot my error?

UPDATE Also tried the simple example, with APP_DEBUG=FOO without success. The toml file wins.

The crazy thing is that to me the code in Environment looks fine, I am just not getting what is going on.

UPDATE
See new comment #47 (comment) below.

[algermissen]

It works with the latest version, which I did not quite have - I had 0,.6 from the github README.

I also checked with the 0.7.0 via crates.io. Also works.

One thing though, that caused trouble for my brain at least: The simple example is broken, because the "APP" prefix[1] used there will not match because it is not lowercased before matching with the already lc-ed key.

[1]

config-rs/examples/simple/src/main.rs

Line 12 in eca93d3

.merge(config::Environment::with_prefix("APP")).unwrap();

Lowercasing should be here

config-rs/src/env.rs

Line 34 in eca93d3

prefix: Some(s.into()),

[algermissen]

I found one more issue with reading the environment. The separator (default '_') is not split once, but several times. For example, if you have APP_CACHE_SIZE in the environment, you do not get a config var "cache_size", but two vars, 'cache' and 'size' (I guess in a hierarchy, but I did not check that).

I found this counter-intuitive when working with env vars.

If this is not a bug, but intended behaviour, a special note in the docs would help avoid this interpretation.

[mehcode]

It was intended. A key like APP_CACHE_SIZE would become cache.size. The idea was to override structured configuration you might have.

I don't want to remove this entirely (as done in #56) but I'd be okay with disabling it by default and having perhaps:

Environment::with_prefix("APP").separator("_")