title: Exporting data from MySQL docker container
body: <p>I use the official MySQL docker image, and I am having difficulty exporting data from the instance without errors. I run my export like this:</p>
  
  <pre><code>docker run -it --link containername:mysql --rm mysql sh -c 
      'exec mysqldump 
          -h"$MYSQL_PORT_3306_TCP_ADDR" 
          -P"$MYSQL_PORT_3306_TCP_PORT" -uroot 
          -p"$MYSQL_ENV_MYSQL_ROOT_PASSWORD" 
       dbname'
  | gz &gt; output.sql.gz
  </code></pre>
  
  <p>However, this results in the warning:</p>
  
  <pre><code>"mysqldump: [Warning] Using a password on the command line interface can be insecure."
  </code></pre>
  
  <p>As the first line of the outputted file. Obviously this later causes problems for any other MySQL processes which are used to consume the data.</p>
  
  <p>Is there any way to suppress this warning from the mysqldump client?</p>