[pxc]

This is nice in its uniformity (same tool works for any distro that has an existing AMI to work with), but it's insanely slow compared to just putting a rootfs together and uploading it as an image.

I think I'd usually rather just use whatever distro-specific tools for putting together a li'l chroot (e.g., debootstrap, pacstrap, whatever) and building a suitable rootfs in there, then finish it up with amazon-ec2-ami-tools or euca2ools or whatever and upload directly. The pace of iteration with Packer is just really painful for me.

[sgarland]

I haven’t played with chroot since Gentoo (which for me, was quite a while ago), so I may be incorrect, but isn’t that approach more limited in its customization? As in, you can install some packages, but if you wanted to add other repos, configure 3rd party software, etc. you’re out of luck.

[pxc]

Nah you can add other repos in a chroot! The only thing you can't really do afaik is test running a different kernel; for that you've got to actually boot into the system.

If you dual-boot multiple Linux systems you can still administer any of the ones you're not currently running via chroot at any time, and that works fine whether you've got third-party repositories or not. A chroot is also what you'd use to reinstall the bootloader on a system where Windows has nuked the MBR or the EFI vars or whatever.

There might be some edge cases like software that requires a physical hardware token to be installed for licensing purposes is very aggressive, so it might also try to check if it's running in a chroot, container, or VM and refuse to play nice or something like that. But generally you can do basically anything in a chroot that you might do in a local container, and 99% of what you might do in a local VM.