Add support for adding volumes to ignite run

[luxas]

Firecracker supports attaching any block device to /dev/vdX in the VM.
We should integrate with CSI (https://github.com/container-storage-interface/spec) or similar software to easily expose attaching additional storage to VMs for persistence (we should also document that we shall treat each VM as ephemeral more or less)

[pditommaso]

I would love to see host volume mounts à la Docker.

[luxas]

I would love to see host volume mounts à la Docker.

This is not possible, as per firecrackers design

We have the possibility to do an one-time copy of files from the host to the guest with run --copy-files, but bidirectional volume mounts are prohibited intentionally by the security model of FC

[pditommaso]

That's a pity, didn't know about this strong requirement.

[luxas]

That's a pity, didn't know about this strong requirement.

After talking to the Firecracker team, they said it's been very often requested, and they're considering
implementing it in the coming months/year. See: firecracker-microvm/firecracker#1180 ✨