I don't have upstart installed on 16.04 but /etc/init has a bunch of .conf scripts in it. Why?

Question

I'm trying to get a command to run on boot and wrote an upstart .conf file and put it into /etc/init. It's a brand new EC2 instance and theres was already bunch of .conf files there. My file wasn't working and I found out that upstart is NOT installed.

Why are there files in /etc/init if there's no upstart? Also, what's the preferred way to run a command on boot in ubuntu 16.04?

Answer 1

Upstart was replaced by systemd in April 2015 (v15.04).¹ There are still many files flying around for compatibility reasons.

See also:

• How does systemd use /etc/init.d scripts?
• What are the pros/cons of Upstart and systemd?
• How to find out if a system uses SysV, Upstart or Systemd initsystem

_{1. https://en.wikipedia.org/wiki/Systemd}