title: spark read blob storage using wildcard
body: <p>I want to read Azure Blob storage files into spark using databricks. But I do not want to set a specific file or <code>*</code> for each level of nesting.</p>
  
  <p>The standard: is <code>**/*/</code> not working. 
  These work just fine:</p>
  
  <pre><code>val df = spark.read.format("avro").load("dbfs:/mnt/foo/my_file/0/2019/08/24/07/54/10.avro")
  val df = spark.read.format("avro").load("dbfs:/mnt/foo/my_file/*/*/*/*/*/*")
  </code></pre>
  
  <p>fails with:</p>
  
  <pre><code>java.io.FileNotFoundException: No Avro files found. If files don't have .avro extension, set ignoreExtension to true
  </code></pre>
  
  <p>for</p>
  
  <pre><code>val df = spark.read.format("avro").load("dbfs:/foo/my_file/test/**/*")
  </code></pre>