title: How to get values from appsettings.json in a console application using .NET Core?
body: <p>i'm creating a console application using .NET Core 3.1 and i would like to have an appsettings json to load all
  environment, paths, variables,... at the beginning of the execution, and then get values from other library classes.
  I have created a 'Settings' class with the data included in the appsettings json.
  This is what i have already by looking out in tutorials but i'm not able to get any value.</p>
  <pre><code>//Start.cs
  public class Startup
  {
          public Startup(IHostingEnvironment env)
          {
              var builder = new ConfigurationBuilder()
                  .SetBasePath(env.ContentRootPath)
                  .AddJsonFile(&quot;appsettings.json&quot;, optional: false, reloadOnChange: true)
                  .AddJsonFile($&quot;appsettings.{env.EnvironmentName}.json&quot;, optional: true)
                  .AddEnvironmentVariables();
  
              Configuration = builder.Build();
          }
  
          public IConfiguration Configuration { get; }
  
          public Startup(IConfiguration configuration)
          {
              Configuration = configuration;
          }
  }
  
  //Settings.cs
   public class Settings
      {
          public ConnectionStrings ConnectionStrings { get; set; }
          public Logging Logging { get; set; }
          public AppSettings AppSettings { get; set; }
      ...
  
  //A class to use it in other lib
   public class Extractor
      {
          private readonly IConfiguration _configuration;
  
          public Extractor(IConfiguration configuration) : this()
          {
              _configuration = configuration;
              Init();
          }
  
          public void Init()
          {
              // Extractor:Min is a variable included in appsettings.json
              Min = _configuration.GetValue&lt;int&gt;(&quot;Extractor:Min&quot;)
                                    
          }
  </code></pre>
  <p>I cannot make a proper Main as i don't know how to initialize everything...what am i missing? I think i've been going in circles for something that easy. Thanks in advance!
  NOTE: i need to get those variables from another library class, not in Main. I don't know how to initialize 'configuration' in other classes in order to use it. Thanks</p>