title: http.FileServer response with wrong mime "Content-Type"
body: <p>I'm using http.FileServer to serve a directory of mp3 files, which my template then <code>src</code> in javascript. The response, however, uses the <code>Content-Type</code> <code>text/html</code> instead of <code>audio/mpeg</code>. How do I set the mime type which the FileServer responds with, I saw this question <a href="https://stackoverflow.com/questions/32301463/setting-the-charset-property-on-the-content-type-header-in-the-golang-http-fil">Setting the &#39;charset&#39; property on the Content-Type header in the golang HTTP FileServer</a> , but I'm still not sure how to override the mime type.</p>
  
  <p>My code looks like the following:</p>
  
  <pre><code>fs := http.FileServer(http.Dir(dir))
  http.Handle("/media", http.StripPrefix("/media", fs))
  http.HandleFunc("/", p.playlistHandler)
  http.ListenAndServe(":5177", nil)
  </code></pre>
  
  <p>and the error I get is:</p>
  
  <pre><code>HTTP "Content-Type" of "text/html" is not supported. Load of media resource http://localhost:5177/media/sample1.mp3 failed.
  </code></pre>