Feature: Allow operations on multiple vms

[nigelkersten]

I propose that anywhere where you're supplying a VM name for any of the command line operations, that you can choose to supply a comma-separated string of VMs to perform operations on multiple VMs at once.

[thbishop]

I'm wondering if this should be baked into fission or if this type of behavior should be driven from shell/command line tools (for loops, gnu parallel, etc.).

If baked into fission, I can see how this could be useful for items such as clone, delete, start, stop, suspend, and snapshot create/delete/revert.

For delete, I think there would need to be some level of internal locking/coordination to ensure the plist file is updated cleanly.

[nigelkersten]

I'd like more native support than the shell offers, I find myself doing this a lot lately:

for vm in vm1 vm2 vm3; do
  fission snapshot revert $vm vanilla
  fission start $vm --headless
done

and I'd much much rather be able to do

fission snapshot revert vm1,vm2,vm3 vanilla
fission start vm1,vm2,vm3 --headless

I suspect that this will be a several pass operation where we add this feature for the simpler methods, and sort out delete/etc where locking matters later.

[thbishop]

Based on your current usage, it looks like serial execution would suffice initially. Is that correct?

The locking comment was my assumption of parallel execution.

Either way, I think this feature makes sense.

[nigelkersten]

Absolutely. Parallel would be gravy, but totally not crucial for now.