config-items

config-items is a library with common configuration items and utility functions.

Install

# Cargo.toml
[dependencies]
config-items = "0.1"

Usage

Define your own "Config" struct and add predefined items from this library.

All examples are here.

Sample configuration for the following example is here.

use config_items::*;
use log::*;
use std::error::Error;
use serde::Deserialize;
use clap::{Arg, Command, ArgMatches};

fn make_args<'a>() -> Command<'a> {
    Command::new("tupacrs")
        .author("My Self <myself@myserver.com>")
        .about("Abput my app")
        .arg(Arg::new("config")
            .short('c')
            .long("config-file")
            .takes_value(true)
            .help(
"Select config filename.
You can also define the pair of environment variables:
  MYAPP_CONF_DIR (defaults to '.')
  MYAPP_CONF_FILE (defaults to 'tupacrs.yaml')
or (all in one)
  MYAPP_CONF_PATH (full path to config file)"))
}

#[derive(Deserialize, Debug)]
struct Config {
    name: String,
    network: Option<Network>,
    #[serde(default)] // use defaults if not present
    logging: Logging,
}

struct MyArgResolver<'a> {
    matches:&'a ArgMatches
}
impl<'a> CFGResolver for MyArgResolver<'a> {
    fn get_from_argument(&self) -> Option<&str> {
        self.matches.value_of("config")
    }
}

struct MyFixedResolver {}
impl CFGResolver for MyFixedResolver {
    fn get_from_argument(&self) -> Option<&str> {
        Some("./examples/myapp.yaml")
    }
}

fn main() -> Result<(), Box<dyn Error>> {
    // This is the recommended setup!!!
    // set_app_id("MYAPP"); // Without this call an attempt to deduce the id from the current executable name will be made
    let (app_id, app_yaml, app_log) = get_app_vars();
    println!("app vars: id=[{app_id}], yaml=[{app_yaml}], log=[{app_log}]");
    let (v_pp, v_c_path, v_c_dir, v_c_file) = get_env_vars();
    println!("env vars: proxy_password=[{v_pp}], config: path=[{v_c_path}], path=[{v_c_dir}], path=[{v_c_file}]");
    let matches = make_args().get_matches();
    // let cfg_file = get_config_file_name(&DefaultResolver{});
    let cfg_file = if matches.contains_id("config") {
        get_config_file_name(&MyArgResolver{ matches:&matches})
    } else {
        get_config_file_name(&MyFixedResolver{})
    };
    // let cfg_file = get_config_file_name(resolver.as_ref());
    // let cfg_file = get_config_file_name(&MyFixedResolver{});
    println!("Using config file [{cfg_file}]");
    let cfg:Config = read_config_from_yaml(&cfg_file)?;
    // println!("Config is [{cfg:#?}]");
    println!("Using config [{}]", cfg.name);
    if let Some(net) = cfg.network {
        println!(" Got network settings: validate ssl:{}", net.skip_ssl_validation());
        if let Some(proxy) = net.proxy {
            // println!("  Got proxy settings: {proxy:?}");
            if let Some(user) = proxy.get_user() {
                println!("   Proxy user will be [{user}]")
            }
            if let Some(pass) = proxy.get_password() {
                println!("   Proxy password will be [{pass}]")
            }
            println!("Final proxy url will be [{}]", proxy.get_url())
        }
    }
    println!("Logging with: {:?}", cfg.logging);
    cfg.logging.init()?;
    error!("This is an ERROR");
    info!("This will be logged");
    debug!("This is DEBUG");
    trace!("This is TRACE");
    
    Ok(())
}

To run the example:

# using MyFixedResolver
$ cargo run cargo run --example myapp
# using MyArgResolver
$ cargo run --example myapp -- -c examples/myapp.yaml
# Override myapp.yaml log level setting
$ RUST_LOG=debug cargo run --example myapp -- -c examples/myapp.yaml

License

Licensed under MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)