title: MediaLink issue when creating a file to Bucket
body: <p>I am using GoLang along as Google App Engine for hosting my web services.</p>
  
  <p>I have been succesful in creating a file to my Firebase storage bucket, but then I would like to get a clean url for it that can be retrieved by clients (iOS / Android) that are authentified with firebase Auth.</p>
  
  <p>What would be the easiest way to get such a link ?</p>
  
  <p>What I have tried :</p>
  
  <p>Getting ObjAttrs object, the bucket object attributes after the creation of the file : 
  This way in Go </p>
  
  <p>attrs, err := obj.Attrs(ctx)</p>
  
  <p>and I do get the attributes, among them a value called MediaLink</p>
  
  <p>A sample of this link would be "<a href="https://www.googleapis.com/download/storage/v1/b/MY_BUCKET/o/MY_FOLDER%2FMY_FILE_NAME?generation=1539262480095558&amp;alt=media" rel="nofollow noreferrer">https://www.googleapis.com/download/storage/v1/b/MY_BUCKET/o/MY_FOLDER%2FMY_FILE_NAME?generation=1539262480095558&amp;alt=media</a>"</p>
  
  <p>Problems :</p>
  
  <p>If I try to open this link into a browser, I get the following error : "Anonymous caller does not have storage.objects.get access to...."</p>
  
  <p>Fair enough, since I'm not authentified with Firebase Auth at this point</p>
  
  <p>But I also tried from a iOS client which is properly authentified with Firebase Auth, and still the retrieval of the link failed.</p>
  
  <p>On the web console, attached to my file in my bucket, I see a link such as this "<a href="https://firebasestorage.googleapis.com/v0/b/MY_BUCKET/o/MY_FOLDER%2FMY_FILENAME?alt=media&amp;token=47630584-f05c-43a2-a04d-8fc21d207181" rel="nofollow noreferrer">https://firebasestorage.googleapis.com/v0/b/MY_BUCKET/o/MY_FOLDER%2FMY_FILENAME?alt=media&amp;token=47630584-f05c-43a2-a04d-8fc21d207181</a>"</p>
  
  <p>This works on both browser and iOS clients.</p>
  
  <p>Now is how can I get by code, in GOLang such URL ?</p>
  
  <p>I have seen no documentation about this.</p>