title: configuring Airflow to work with CeleryExecutor
body: <p>I try to configure Airbnb AirFlow to use the CeleryExecutor like this:</p>
  
  <p>I changed the <code>executer</code> in the airflow.cfg from <code>SequentialExecutor</code> to <code>CeleryExecutor</code>:</p>
  
  <pre><code># The executor class that airflow should use. Choices include
  # SequentialExecutor, LocalExecutor, CeleryExecutor
  executor = CeleryExecutor
  </code></pre>
  
  <p>But I get the following error:</p>
  
  <pre><code>airflow.configuration.AirflowConfigException: error: cannot use sqlite with the CeleryExecutor
  </code></pre>
  
  <p>Note that the <code>sql_alchemy_conn</code> is configured like this:</p>
  
  <pre><code>sql_alchemy_conn = sqlite:////root/airflow/airflow.db
  </code></pre>
  
  <p>I looked at Airflow's GIT (<a href="https://github.com/airbnb/airflow/blob/master/airflow/configuration.py" rel="noreferrer">https://github.com/airbnb/airflow/blob/master/airflow/configuration.py</a>)</p>
  
  <p>and found that the following code throws this exception:</p>
  
  <pre><code>def _validate(self):
          if (
                  self.get("core", "executor") != 'SequentialExecutor' and
                  "sqlite" in self.get('core', 'sql_alchemy_conn')):
              raise AirflowConfigException("error: cannot use sqlite with the {}".
                  format(self.get('core', 'executor')))
  </code></pre>
  
  <p>It seems from this <code>validate</code> method that the <code>sql_alchemy_conn</code> cannot contain <code>sqlite</code>.</p>
  
  <p>Do you have any idea how to configure the <code>CeleryExecutor</code> without sqllite? please note that I downloaded rabitMQ for working with the CeleryExecuter as required.</p>