How do I add a startup script to an existing VM from the developer console?

Question

I have an existing, already configured VM on Google Cloud Platform. It was created without a startup script, but I\'d like to add one now.

How do I add it from the conso

Answer 1

Thanks to mimming's answer, I was looking for this to solve my issue regarding multiple IP, and his answer help me get started and finally solved my problem by add below startup-script when reboot the instance.

#! /bin/bash
sleep 60
/usr/sbin/ip route add default via 10.8.8.1 dev eth1 table rt1
/usr/sbin/ip rule add from 10.8.8.3/32 table rt1
/usr/sbin/ip rule add to 10.8.8.3/32 table rt1

remember to add "sleep 60" otherwise it might not working cause the networking not started yet.