Packer: amazon-chroot mount_partition option does not allow to mount entire device

[pa-yourserveradmin-com]

The amazon-chroot builder works incorrectly with EBS volumes on HVM instances: the builder, relaying on mount_partition option default behavior introduced in 460e2da2485d1392b6a28103e37f98331d85e625 and patched in 09543fc4e7de662488974178d8979083ec99bc04, attempts to mount /dev/xvdf1 while there is no such partition and entire /dev/xvdf must be mounted.

Problem lines:

• https://github.com/hashicorp/packer/blob/master/builder/amazon/chroot/builder.go#L115 (there is no way to tell Packer to skip mount partition number);
• https://github.com/hashicorp/packer/blob/master/builder/amazon/chroot/step_mount_device.go#L79 (deviceMount for HVM instances always has numeric mount partition appended to device name).

It will be fine to have an ability to manage this out by using template variables, for example, by changing default behavior for mount_partition option as described in this patch.

Environment, logs and how to reproduce:

• Packer version: 1.2.2
• Host platform: AWS Debian 7 Wheezy (source AMI ID: ami-61e56916)
• Debug log output is here
• The example template and scripts needed to reproduce the bug can be found here

[SwampDragons]

I believe this is a duplicate of #5848; your patch might be useful in addressing these. I'm closing this as a duplicate and copying @mwhooker who was looking into the original issue.

[SwampDragons]

By the way -- this issue and repro case are probably the most beautiful issue I've ever seen. Thank you for doing such a thorough job of making it easy for me to reproduce.

[SwampDragons]

This wasn't a duplicate of 5848 after all, but I was able to fix it pretty easily thanks to your investigation; it'll be closed by #6194

[hashibot[bot]]

I'm going to lock this issue because it has been closed for _30 days_ ⏳. This helps our maintainers find and focus on the active issues.

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