title: Azure azcopy fails after AAD success authentication
body: <p>I am trying to use azcopy tool from Ubuntu 20.04 to upload file to Azure Blob.</p>
  <p>I am authenticated with AAD and SP:</p>
  <pre><code>export AZCOPY_SPA_CLIENT_SECRET=&quot;12345678&quot;
  azcopy login --service-principal  --application-id abc --tenant-id=xyz
  </code></pre>
  <p>Here I get auth success:</p>
  <pre><code>INFO: SPN Auth via secret succeeded.
  </code></pre>
  <p>However when I run:</p>
  <pre><code>azcopy copy './myfile' 'https://mystorageacc.blob.core.windows.net/mycontainer/myfile'
  </code></pre>
  <p>I get this error:</p>
  <pre><code>failed to perform copy command due to error: Login Credentials missing. No SAS token or OAuth token is present and the resource is not public
  </code></pre>
  <p>Obviously the AAD service principals are in the role 'Storage Blob Data Contributor' of the storage account.</p>
  <p>What is wrong? thanks</p>