Asp.Net core how can I replace the Configuration Manager
<p>I am new to <strong>ASP.NET Core RC2</strong> and I was wondering how can I get some configuration settings and apply it to my method. For Instance in my <code>appsettings.json</code>I have this specific setting</p>

<pre><code>"ConnectionStrings": {
    "DefaultConnection": 
        "Server=localhost;User Id=postgres;port=5432;Password=castro666;Database=dbname;"
  }
</code></pre>

<p>In my Controller every time I want to query the database I have to use this setup</p>

<pre><code> using (var conn = 
     new NpgsqlConnection(
         "Server=localhost;User Id=postgres;port=5432;Password=castro666;Database=dbname;"))
 {
     conn.Open();
 }
</code></pre>

<p>The obvious pitfull here is that if I want to add more to the configuration I have to change every single instance of that method. My question is how can I get the <code>DefaultConnection</code> in the <code>appsettings.json</code> so that I can do something like this</p>

<pre><code> using (var conn = 
     new NpgsqlConnection(
         ConfigurationManager["DefaultConnection"))
 {
     conn.Open();
 }
</code></pre>