title: setting system variables in MySQL running as docker container
body: <p>I have used docker to setup mysql server taken from <a href="https://registry.hub.docker.com/_/mysql/" rel="nofollow">https://registry.hub.docker.com/_/mysql/</a> , I know that we can set up environment variables using several options while running an image as"-e , -env or --env-file" which works absolutely fine as I want. But now I want to edit my system variables for MySQL say "max_connections=300". Is there a way we can use these options to achieve this. I have tried using --env-file option to update system variables but no success :( would be really very helpful if anyone can give pointers on this.</p>
  
  <p>Thanks,
  ~yash</p>