How reference a my app's config directory when running from release

help
1

Observation

When I run the app using cargo run --release from the project root, the app finds the config directory ./config. However, when I run the app calling the ./target/release/<app name>, the reference is lost/broken.

The source ./src/config.rs references the config directory as following:

const CONFIG_FILE_PATH: &str = "config/default.toml";

When in a Docker context

In general, what is a good way to copy and point to the config files for a dockerized app?

2

This should not happen in any normal Unix shell. How are you opening the file?

Docker or no docker, config files are best placed at fixed, pre-determined locations. If you don't want to do that, you can simply pass the path as an arg.

3

That makes sense.

Perfect. Based on that, the culprit is how I'm using the config.

use config::{Config as RConfig, Environment, File};
...
const CONFIG_FILE_PATH: &str = "config/default.toml";
const CONFIG_FILE_ROOT: &str = "config";

impl Config {
    pub fn new() -> Result<Self> {
        let mut s = RConfig::default();

        // default
        s.merge(File::with_name(CONFIG_FILE_PATH))
            .context("Unable to load the default config")?;

        // use env Development, Production or Testing to set override
        let env = env::var("RUST_ENV").unwrap_or_else(|_| "Development".into());

        s.set("env", env.clone())?;
        s.merge(File::with_name(&format!("{}/{}", CONFIG_FILE_ROOT, env)).required(false))
            .context(format!("Unable to load {}/{}.toml", CONFIG_FILE_ROOT, env))?;

        s.merge(Environment::new().separator("_"))?;

        s.try_into().context("Unable to instantiate Config struct")
    }
}

lazy_static! {
    pub static ref CONFIG: Config = Config::new().unwrap();
}
4

My guess would be File::with_name does something with the path - it doesn't directly open it. Otherwise it should open.

5

In the event I copy the app into /usr/local/bin that is included in my PATH, given my current setup, would that mean I need to include the config/ in the /usr/local/bin?

6

I found the following post that goes into Different output of env::current_dir() - #7 by kornel

The key is to launch the app from a directory where the ./config exits. The working directory is that from where I launch the app... 101 stuff.

@RedDocMD thank you for your help.

7

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