title: Serilog JsonFormatter in an ASP.Net Core 2 not being applied from appsettings file
body: <p>I have an ASP.Net Core 2 web application where I'm trying to configure SeriLog to output in JSON format, configured via an appsettings.json file. I cannot get this to work with either the standard Serilog.Formatting.Json.JsonFormatter or the compact Serilog.Formatting.Compact.CompactJsonFormatter.</p>
  
  <p>I see there's a similar question asked <a href="https://stackoverflow.com/questions/40880261/configuring-serilog-rollingfile-with-appsettings-json/41383977#41383977">here</a>, but there seems to be no conclusive answer using appsettings.json, and the thread has gone quiet for over a year (and I don't have enough reputation to comment to nudge further responses).</p>
  
  <p>I'm using the following SeriLog packages:</p>
  
  <ul>
  <li>Serilog.AspNetCore - 2.1.0</li>
  <li>Serilog.Enrichers.Environment - 2.1.2</li>
  <li>Serilog.Enrichers.Thread - 3.0.0</li>
  <li>Serilog.Formatting.Compact - 1.0.0</li>
  <li>Serilog.Settings.Configuration - 2.4.0</li>
  <li>Serilog.Sinks.RollingFile - 3.3.0</li>
  </ul>
  
  <p>The SeriLog section of my appsettings.json file reads:</p>
  
  <pre><code>"Serilog": {
    "Using": ["Serilog.Sinks.RollingFile"],
    "MinimumLevel": {
      "Default": "Verbose",
      "Override": {
        "Microsoft": "Warning",
        "System": "Warning"
      }
    },
    "WriteTo": [
      {
        "Name": "RollingFile",
        "Args": {
          "pathFormat": "C:\\Logs\\MLSBPortal-{Date}.txt",
          "formatter": "Serilog.Formatting.Compact.CompactJsonFormatter, Serilog.Formatting.Compact",
          "restrictedToMinimumLevel": "Debug",
          "retainedFileCountLimit": "10",
          "outputTemplate": "{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level}] [{ThreadId}] [{SourceContext}] [{SessionId}] [{UserName}]: {Message}{NewLine}{Exception}"
        }
      }
    ],
  </code></pre>
  
  <p>with the formatter line modified to the following when testing with the default JSON formatter:</p>
  
  <pre><code>"formatter": "Serilog.Formatting.Json.JsonFormatter, Serilog",
  </code></pre>
  
  <p>As suggested in multiple other places.</p>
  
  <p>My output is being written fine, but the formatter setting does not appear to be making any difference to the output.</p>
  
  <p>Am I doing something wrong here, or is this functionality not implemented via a configuration file read yet?</p>
  
  <p>Thanks in advance for any help.</p>