Add support for reusing a virtual machine

[Hi-Angel]

Community Note

Please vote on this issue by adding a 👍 reaction to the original issue to help the community and maintainers prioritize this request. Please do not leave "+1" or "me too" comments, they generate extra noise for issue followers and do not help prioritize the request. If you are interested in working on this issue or have submitted a pull request, please leave a comment.

Description

Currently there's no functional to install an ISO to an existing VM. Rephrasing in packer terms: there's no way to build a machine image in vsphere by re-using an existing VM.

As a matter of fact, judging by the lack of answers here, it doesn't seem to be possible for any hypervisor, not just vsphere.

Use Case(s)

• Limiting the existing VMs to certain number of pre-created ones. packer is for automated VMs creation, and if there's a bug in the logic that calls packer, there may be an explosion of creating new VMs.
• (our usecase) working around missing functionality in the plugin. For example, there's currently no way to create a pair of VMs connected as an active/active or active/passive cluster (that is having VMs with simultaneous access to the same "disk" or rather "disk file"). Such functional is also difficult to implement because it does not work well in vSphere to start with. E.g. if you try to destroy such VM that shares a disk you'll get a vague concurrent access error.

[Hi-Angel]

I want to point out that I'm currently working on it. I'm new to both Packer and Go language, but hopefully if resources permit I will have it implemented.

Any advises are welcome.

[Hi-Angel]

Is there a way to avoid the plugin being killed while being paused under gdb?

[tenthirtyam]

I've added the stage/thinking label to this one. This seems to be a rather interesting use case but likely not quite common. Would be good to get community reactions 👍 👎 👀 or thoughts before implementing such feature.