title: Does Airflow support connection over TLS for broker url?
body: <p>Currently I am trying to use Apache Airflow with Celery executor. For this I have Redis service from IBM cloud. This service has the TLS connection type which means it has the redis protocol as <strong>rediss://</strong>. Side not: I am using puckel's airflow dockerfile. </p>
  
  <p>I have set redis parameters and my broker url is in the form of <strong>rediss://username:password@hostname:port/virtual_host</strong>. While I try to run for example, Flower I get these errors: </p>
  
  <p><strong>Secure redis scheme specified (rediss) with no ssl options, defaulting to insecure SSL behaviour.</strong></p>
  
  <p>Steps that I have done till now:</p>
  
  <ul>
  <li>I have added the following lines to the entrypoint.sh:</li>
  </ul>
  
  <pre><code>    : "${AIRFLOW__CELERY__SSL_ACTIVE:="True"}"
      : "${AIRFLOW__CELERY__BROKER_USE_SSL:="{'ssl_cert_reqs': ssl.CERT_REQUIRED, 'ssl_ca_certs': '/6be25d73-0600-11ea-9bce-eaebe975ceba.crt'}"}"
      AIRFLOW__CELERY__BROKER_USE_SSL="${AIRFLOW__CELERY__BROKER_USE_SSL}"
      AIRFLOW__CELERY__SSL_ACTIVE="${AIRFLOW__CELERY__SSL_ACTIVE}"
      export AIRFLOW__CELERY__SSL_ACTIVE
      export AIRFLOW__CELERY__BROKER_USE_SSL
  </code></pre>
  
  <ul>
  <li>I have tried to use redis:// with the same broker url, but flower even did not started.</li>
  </ul>