title: Which values does WebHost read from appsettings.json
body: <p>In .Net Core you can self host a web server using <code>WebHost</code>. There is a method called <code>CreateDefaultBuilder()</code>, to which the <a href="https://docs.microsoft.com/en-us/aspnet/core/fundamentals/host/web-host?view=aspnetcore-2.1" rel="noreferrer">Microsoft documentation</a> states the following:</p>
  <blockquote>
  <p><code>CreateDefaultBuilder</code> performs the following tasks:</p>
  <ul>
  <li>Loads app configuration from:</li>
  <li>appsettings.json.</li>
  </ul>
  </blockquote>
  <p>However, there doesn't seem to be any documentation on which parameters you can put into <code>appsettings.json</code> to have the <code>WebHost</code> automatically get configuration values other than the default values.</p>
  <p>For example, I tried adding the following to my <code>appsettings.json</code>, but the server is started with <code>http://localhost:5000</code> regardless:</p>
  <pre><code>{
    &quot;Kestrel&quot; : {
      &quot;urls&quot; : &quot;http://*:8080&quot;
    },
    &quot;server&quot; : {
      &quot;urls&quot; : &quot;http://*:8080&quot;
    }
  }
  </code></pre>
  <p>I know I can read <code>appsettings.json</code> myself using <code>ConfigurationBuilder</code>, but that sort of defeats the purpose of the documentation</p>
  <p>So, what do I need to put into my <code>appsettings.json</code> file to have <code>CreateDefaultBuilder()</code> not use the default values? A list of all possible values to put into <code>appsettings.json</code> would be welcome as well.</p>