CI/CD pipeline PXE boot image Ubuntu
Solution 1:
Packer CI/CD pipeline mentioned would not provide functionality to create PXE boot image or ISO image as of now. Packer doesn't provide PXE boot builder as of writing this answer (Date: 18/09/2020).
It is possible to use Ubuntu desktop image instead of Server image with a preseed for pxe boot.
Packer is great tool for building server images, you can use it for Desktop images. It will create images in form of Virtual machine or cloud provider image. According to me Considering your use case, Packer is not correct choice.