Being cheap with Github Actions

tl;dr

Don’t bother fiddling with GitHub actions for Free packer builds with KVM

Less tl;dr

• Noticed github actions are free*

  • https://docs.github.com/en/actions/reference/usage-limits-billing-and-administration
  • They need to take less than 6 hours per job, and 72 hours for the entire workflow

• Tried to port https://github.com/pentesterwtf/packer-kali and https://github.com/pentesterwtf/packer-windows to pure github actions

  • Github action runners don’t have virtualisation support
  • Tried it with TCG instead of KVM to avoid needing virtualisation

• Results were as follows:

  • Building Kali locally with kvm takes 9 minutes
  • Building Kali locally using TCG takes 43 minutes
  • Building Kali on github actions using TCG took 98 minutes

• Building win10 locally with KVM takes 30 minutes

  • Building it with TCG just dies
  • Atttempting to boot a prebuilt Windows 10 image with TCG took over an hour before ^C

Seeing as I can just debootstrap Kali and Windows seemingly won’t build, I think I’ll stay away from free Github Actions compute for now.