Need a Success / Failure notification mechanism when cloud-init finishes.

[Sankar Tanguturi]

I discussed this issue during the 'cloud-init' summit that happened in August 2017. Logging a bug for tracking purposes. Today, there is no way for datasources to get notified about success / failure when cloud-init finishes executing.

Following is an example:

> From cloudinit/sources/DataSourceOVF.py

            # TODO: Need to set the status to DONE only when the
            # customization is done successfully.
            enable_nics(self._vmware_nics_to_enable)
            set_customization_status(
                GuestCustStateEnum.GUESTCUST_STATE_DONE,
                GuestCustErrorEnum.GUESTCUST_ERROR_SUCCESS)

Ideally, the datasourceOVF wants to get notified when the cloud-init finally completes. Then, the datasource needs to send success / failure events to the underlying hypervisor. But today the mechanism / framework is not available. So, the datasourceOVF just blindly returns SUCCESS to the hypervisor without even waiting for the completion.

We really really need a better framework / mechanism to handle situations like this. Please do let me know if any information is requried.

Thanks
Sankar.

[Scott Moser (smoser)]

There are two paths we could pursue for this:
a.) Utilize reporting mechanism (reporting.handlers.ReportHandler), which already does this in many senses. MAAS uses this mechanism to accomplish both "status" events and "pass/fail". This general mechanism is already in place. To use it for vmware we would have to add some Reporter that worked for vmware.

b.) Modify cloud-init to call a 'report_status' function on a datasource if that function was present. We'd just change cloud-init to call that at different points in its runtime.

The only issue with this is that it very much is implementing a subset of what reporting already does do.

So I'd prefer to work towards the ReportHandler solution (a).

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/3031