.NET Core console application, how to configure ap

Question

I have a .NET Core 1.0.0 console application and two environments. I need to be able to use appSettings.dev.json and appSettings.test.json based on environment variables I set at run time. This seems to be quite straight forward for ASP.NET Core web applications, via dependency injection and IHostingEnvironment and the EnvironmentName env. variable, however how should I wire things up for the console application (besides writing my own custom code that uses Microsoft.Framework.Configuration.EnvironmentVariables)?

Thank you.

Answer 1

You can do this for ASP.Net Core environment variable (ASPNETCORE_ENVIRONMENT): -

using Microsoft.AspNetCore.Hosting;
using System;

public class Program {
    private static string HostingEnvironment => Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
    private static bool IsEnvironment(string environmentName) => HostingEnvironment?.ToLower() == environmentName?.ToLower() && null != environmentName;

    private static bool Development => IsEnvironment(EnvironmentName.Development);
    private static bool Production => IsEnvironment(EnvironmentName.Production);
    private static bool Staging => IsEnvironment(EnvironmentName.Staging);

    public static void Main(string[] args) { // Your code here }
}

Then you can simply use the property

    public static void Main(string[] args) {
        if (Development){
            // Blow up the planet
        }
    }

Answer 2

This is how we do it in our .netcore console app. The key here is to include the right dependencies on your project namely (may be not all, check based on your needs) and copy to output the appSetting.json as part of your buildoptions

  {
       "Microsoft.Extensions.Configuration": "1.0.0",
       "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
       "Microsoft.Extensions.Configuration.FileExtensions": "1.0.0",
       "Microsoft.Extensions.Configuration.Json": "1.0.0",
  } 
    "buildOptions": {
    "emitEntryPoint": true,
    "copyToOutput": {
       "include": [
       "appsettings*.json",
       "App*.config"
                 ]
          }
},

  using Microsoft.Extensions.Configuration;
  namespace MyApp
  {
    public static void Main(string[] args)
    {
        var environmentName = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");


        var builder = new ConfigurationBuilder()
            .AddJsonFile($"appsettings.json", true, true)
            .AddJsonFile($"appsettings.{environmentName}.json", true, true)
            .AddEnvironmentVariables();
        Configuration = builder.Build();
        var myConnString= Configuration.GetConnectionString("SQLConn");
    }

}

Answer 3

There are two IHostingEnvironment interfaces that you should use. One is for ASP.NET Core Applications, the other one is for .NET Core Console applications. You can use this code example for both:

using System;
using System.IO;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.Hosting.Internal;

namespace MyApplication.Common
{
    public static class ConfigurationFactory
    {
        /// <summary>
        /// Use for ASP.NET Core Web applications.
        /// </summary>
        /// <param name="config"></param>
        /// <param name="env"></param>
        /// <returns></returns>
        public static IConfigurationBuilder Configure(IConfigurationBuilder config, IHostingEnvironment env)
        {
            return Configure(config, env.EnvironmentName);
        }

        /// <summary>
        /// Use for .NET Core Console applications.
        /// </summary>
        /// <param name="config"></param>
        /// <param name="env"></param>
        /// <returns></returns>
        private static IConfigurationBuilder Configure(IConfigurationBuilder config, Microsoft.Extensions.Hosting.IHostingEnvironment env)
        {
            return Configure(config, env.EnvironmentName);
        }

        private static IConfigurationBuilder Configure(IConfigurationBuilder config, string environmentName)
        {
            return config
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddJsonFile($"appsettings.{environmentName}.json", optional: true, reloadOnChange: true)
                .AddEnvironmentVariables();
        }

        /// <summary>
        /// Use for .NET Core Console applications.
        /// </summary>
        /// <returns></returns>
        public static IConfiguration CreateConfiguration()
        {
            var env = new HostingEnvironment
            {
                EnvironmentName = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT"),
                ApplicationName = AppDomain.CurrentDomain.FriendlyName,
                ContentRootPath = AppDomain.CurrentDomain.BaseDirectory,
                ContentRootFileProvider = new PhysicalFileProvider(AppDomain.CurrentDomain.BaseDirectory)
            };

            var config = new ConfigurationBuilder();
            var configured = Configure(config, env);
            return configured.Build();
        }
    }
}