Conphig v1.0 published

#nuget #dotnet

Written by Anders Marzi Tornblad

Nuget logotypeConphig (Nuget package), latest version: 1.0.2

Repetitive tasks are repetitive

There are a lot of things in coding that I end up doing over and over again. For those things, I keep a knowledge base: a set of private gists in GitHub for the purely code-based things, and a large number of how-to documents in Google Drive.

One of the things I have kept as a gist until now deals with getting runtime configuration for a command line tool, in a coherent way, from command line arguments, a JSON configuration file, environment variables or default settings. I want to be able to get settings from all those sources, with the right precedence order, efficiently. And I want the configuration specification to be a minimal piece of code.

NuGet Packages

For some reason, I just never thought of publishing prepackaged solutions like this properly. Well, there's this one npm package that I made about three years ago, mostly as an experiment, but other than that, I had never published packages to the world.

But now, there is the Conphig NuGet package that aims to solve runtime configuration loading for .NET 5 projects. And it just got bumped to version 1.0.0!

How to use it

After installing the Conphig package, create a simple POCO class, and place your configuration items as properties inside. For each property, decorate it with JsonPropertyName, CommandLine, EnvironmentVariable and Default attributes to control how that property is loaded from JSON files, command line arguments and environment variables, and what the default value is. Like this:

using System.Text.Json.Serialization;
using ATornblad.Conphig;

namespace MyApp
{
    public class Setting
    {
        [JsonPropertyName("title")]
        [EnvironmentVariable("TITLE")]
        [CommandLine("-t", "--title")]
        public string Title { get; set; } = "Default title";
        
        [JsonPropertyName("verbose")]
        [EnvironmentVariable("VERBOSE")]
        [CommandLine("-v", "--verbose")]
        public bool Verbose { get; set; } = false;
        
        [JsonPropertyName("minAge")]
        [EnvironmentVariable("MIN_AGE")]
        [CommandLine("--min-age")]
        public int? MinAge { get; set; }
        
        [EnvironmentVariable("API_TOKEN")]
        public string ApiToken { get; set; }
        
        [JsonPropertyName("categories")]
        [CommandLine("-c", "--category")]
        public string[] Categories { get; set; }
    }
}

Then, to load the configuration settings, just add a call to Config.Load<T> to your application's startup code:

using ATornblad.Conphig;

namespace MyApp
{
    public class Program
    {
        public void Main(string[] args)
        {
            var config = Config.Load<Setting>();
            Console.WriteLine($"Title: {config.Title}");
            Console.WriteLine($"Verbose Output: {config.Verbose}");
            Console.WriteLine($"Minimum Age: {config.MinAge}");
            Console.WriteLine($"Api Token: {config.ApiToken }");
        }
    }
}

I hope you will find my little tool useful.

The latest version of the code is always available in the GitHub repository.