Do not run Erlang VM as PID 1

[sirn]

Subject of the issue

Running non-Init process as PID 1 is a Bad Idea ™.

Your environment

Docker image generated from Dockerfile

Steps to reproduce

1. Build docker image (docker build)
2. Run it.

Expected behavior

Lightweight init being ran as PID 1, such as Tini, or S6.

Actual behavior

Erlang VM is running as PID 1.

[unnawut]

Noting down for my own understanding from your ref link:

Suppose that your container contains a web server that runs a CGI script that's written in bash. The CGI script calls grep. Then the web server decides that the CGI script is taking too long and kills the script, but grep is not affected and keeps running. When grep finishes, it becomes a zombie and is adopted by the PID 1 (the web server). The web server doesn't know about grep, so it doesn't reap it, and the grep zombie stays in the system.

[sirn]

Update: we're going with S6.