`pm2 startup` does not take into account authbind nor `pm2` alias

In the docs we suggest to users to add the following line to their non-root user's ~/.bashrc file.

alias pm2='authbind --deep pm2'

However this ONLY works for when pm2 is started as this user in this session.

Upon calling pm2 save, the following output occurs:

user@ubuntu:~$ pm2 save
[PM2] Saving current process list...
[PM2] Successfully saved in /home/user/.pm2/dump.pm2

This is OK actually, the problem is the next step:

user@ubuntu-2gb-nyc3-01:~$ pm2 startup
[PM2] Init System found: upstart
[PM2] You have to run this command as root. Execute the following command:
sudo env PATH=$PATH:/home/user/.nvm/versions/node/v8.3.0/bin /home/user/.config/yarn/global/node_modules/pm2/bin/pm2 startup upstart -u user --hp /home/user

Note that the pm2 command here does not utilize authbind.

Therefore when you run that command as root, and then run sudo reboot to reboot the server, the ONLY way your apps will run again properly is if you manually log in as user and run:

authbind --deep pm2 update

I think that we should detect if the user is using authbind and then insert that in the copy/paste snippet or fix the startup command?

This issue is related to the comment here https://github.com/Unitech/PM2/issues/1038#issuecomment-211459999.

Perhaps allow the user to pass a flag --authbind to pm2 startup command? And then take that into consideration here https://github.com/Unitech/pm2/blob/43b6000171a28e09cc25467e1b46fcd7f7ac7a08/lib/API/Startup.js#L281?

Read lib/API/Startup.js around line 281 and reproduce the documented pm2 save and pm2 startup commands using the authbind alias. Determine how startup output should account for authbind or an --authbind option, with completion shown by a generated command that preserves app startup after reboot.