multiple libvirt-provider instances share same storage

[lukas016]

Problem description

Current implementation of store uses filesystem for storage api.Machine objects. We are using mutex for avoid of race condition during modified api.Machine. But we don't have any protection between running multiple instances of libvirt-provider.

It can create race condition during upgrade of libvirt-provider, when multiple instances of libvirt-provider run simultaneously.

I think we need to fix this special case. One of possible solution is use lock base on file (same logic as flock). Maybe: https://pkg.go.dev/github.com/theckman/go-flock

What do you think?

[lukas016]

we decided only one instance of pod can run at the time.