Hey there,
After reviewing your project description its clear that you want someone to configure a fully functional FTP server on your Ubuntu Virtual Machine at GCP and you want to use passwd file for storing the passwords instead of using a database.
I'm very experienced with System Administration, Network Administration, Google Cloud Platform.
I'll be happy to do this project for you.
Thanks in advance for giving the opportunity to working with you.
Have a good day.
Best Regards,
Serazum Munir.