Cleanup VM in case of a failure

[fkorotkov]

Fixes #115

[fkorotkov]

@sparshev FYI

[sparshev]

Sorry, see just one file is changed, but according to the builder you have 3 separated steps for this matter:

• step_clone_vm.go
• step_create_linux_vm.go
• step_create_vm.go

But I'm not sure I really understand the codebase, so could be wrong.

[fkorotkov]

Good catch, @sparshev! I've extracted cleanup in a separate step which is the first one. Cleanup functions are called in reverse order so it will be called the last.

[sparshev]

Yep, now looks better!) Do you think this PR will contain a fix for Ctrl-C issue as well, because in description it says Fixes #115. Or I can create a separated issue about Ctrl-C.

[fkorotkov]

It seems it will be handled according to Packer documentation:

Cancels are most commonly triggered by external interrupts, such as the user pressing Ctrl-C. Packer will only exit once all the builders clean up...

[sparshev]

I'm talking about a bit different behavior: the issue with Ctrl-C that Tart VM is going down immediately after Ctrl-C, not after cleanup operation... So when you press Ctrl-C in packer with --on-error=ask the VM should continue to live until c and enter were pressed.

[fkorotkov]

Oh. I think I misunderstood you but I still think that Ctrl+C will be handled since shutdown -h now is send in Cleanup of a run step.

@edigaryev is on PTO so I'm going to merge now so we can do a release. He'll review the change post-factum.

[torarnv]

Does this take the packer build -on-error= argument into account?

-on-error=[cleanup|abort|ask|run-cleanup-provisioner] If the build fails do: clean up (default), abort, ask, or run-cleanup-provisioner.

If I pass ask and press Ctrl+C, the VM is still deleted. I would have expected it to stay around, so I could debug what went wrong.

It seems to work fine if the cancellation is coming from a step, e.g. if the SSH times out. In that case the cleanup is not run when I choose so via the ask menu.

[torarnv]

"Internal" failure. Choice respected:

==> macos.tart-cli.install-os: Creating virtual machine...
    macos.tart-cli.install-os: Installing OS...
    macos.tart-cli.install-os: 0%
    macos.tart-cli.install-os: Error: An error occurred during installation. Installation failed.
==> macos.tart-cli.install-os: Failed to create a VM: Bad exit status: 1
==> macos.tart-cli.install-os: Step "stepCreateVM" failed
==> macos.tart-cli.install-os: [c] Clean up and exit, [a] abort without cleanup, or [r] retry step (build may fail even if retry succeeds)? a
==> macos.tart-cli.install-os: Failed to create a VM: Bad exit status: 1
==> macos.tart-cli.install-os: Step "stepCreateVM" failed, aborting...
==> macos.tart-cli.install-os: aborted: skipping cleanup of step "stepCleanVM"
Build 'macos.tart-cli.install-os' errored after 2 minutes 10 seconds: Failed to create a VM: Bad exit status: 1

Ctrl+C. Choice ignored:

==> macos.tart-cli.install-os: Creating virtual machine...
    macos.tart-cli.install-os: Installing OS...
    macos.tart-cli.install-os: 0%
Cancelling build after receiving interrupt
==> macos.tart-cli.install-os: Failed to create a VM: Bad exit status: -1
==> macos.tart-cli.install-os: Step "stepCreateVM" failed
==> macos.tart-cli.install-os: [c] Clean up and exit, [a] abort without cleanup, or [r] retry step (build may fail even if retry succeeds)? a
==> macos.tart-cli.install-os: Cleaning up virtual machine...
    macos.tart-cli.install-os: failed to open lock file file:///Users/torarne/.tart/vms/macos-preinstall:13.6.0+22G120/config.json: No such file or directory
Build 'macos.tart-cli.install-os' errored after 1 second 874 milliseconds: Failed to create a VM: Bad exit status: -1

[edigaryev]

Ctrl+C. Choice ignored:

This seems to be done intentionally by the Packer:

func ask(ui packersdk.Ui, name string, state multistep.StateBag) askResponse {
	ui.Say(fmt.Sprintf("Step %q failed", name))

	result := make(chan askResponse)
	go func() {
		result <- askPrompt(ui)
	}()

	for {
		select {
		case response := <-result:
			return response
		case <-time.After(100 * time.Millisecond):
			if _, ok := state.GetOk(multistep.StateCancelled); ok {
				return askCleanup
			}
		}
	}
}

I've created a hashicorp/packer-plugin-sdk#226 to address this.

[torarnv]

Awesome @edigaryev !