With Amazon Linux 2 you need to use the .platform folder to supply elastic beanstalk with installation scripts.
We recommend using platform hooks to run custom code on your environment instances. You can still use commands and container commands in .ebextensions configuration files, but they aren't as easy to work with. For example, writing command scripts inside a YAML file can be cumbersome and difficult to test.
So you should add a prebuild hook (example) into a .platform folder to install supervisor and a postdeploy hook (example) to restart supervisor after each deployment.
There is an ini file (example) used in the script; which is made for laravel specific.
Make sure that the .sh files from the .platform
folder are executable before deploying your project:
$ chmod +x .platform/hooks/prebuild/*.sh
$ chmod +x .platform/hooks/postdeploy/*.sh