title: Spark Structured Streaming with Kafka SASL/PLAIN authentication
body: <p>Is there a way of connecting a Spark Structured Streaming Job to a Kafka cluster which is secured  by SASL/PLAIN authentication? </p>
  
  <p>I was thinking about something similar to:</p>
  
  <pre><code>val df2 = spark.read.format("kafka")
      .option("kafka.bootstrap.servers", "localhost:9092")
      .option("kafka.sasl.mechanism", "PLAIN")
      .option("kafka.security.protocol", "SASL_PLAINTEXT")
      .option("kafka.sasl.jaas.config", "org.apache.kafka.common.security.plain.PlainLoginModule required username=...")
      .option("subscribe", "topic1")
      .load();
  </code></pre>
  
  <p>It seems like while Spark Structured Streaming recognizes the <code>kafka.bootstrap.servers</code> option, it does not recognize the other SASL-related options. Is there a different way?</p>