Feature/observe backup and restore

[robertlyson]

Let's summarize what has been done so far:

• observable for snapshot and restore features
• ElasticClient.SnapshotObservable uses under the hood ElasticClient.SnapshotStatus
• ElasticClient.RestoreObservable uses ElasticClient.RecoveryStatus
• status is reported back with defined time period (thanks @Mpdreamz for help with Timer 👍 )

One integration test has been written for this feature(SnapshotRestoreObservable), but it is failing so far. Seems to be that the problem is in the ElasticClient.RecoveryStatus, which returns recovery status as done all the time.

Feel free to take over this issue - hope I'll find some time before next release to be able to close this topic together with you.

[gmarz]

This is awesome! Thanks @robertlyson

[robertlyson]

Now I see where the problem is.

In the integration test, I'm making restore request with index name replacement option, but I'm checking recovery status for original index name.

I'll push this fix soon.

[Mpdreamz]

Hi @robertlyson I see you amended the PR 👍

Please ping us when you are ready for us to review, can't wait to 🚢 🇮🇹

[robertlyson]

Hello @Mpdreamz,

I think, more reliable tests is the last think to do for this feature. I'm still thinking about this, but good solution didn't pop up yet.
Current test still depends on machine which runs tests. Maybe you will find other way to deal with this.

From minor issues:

1. I put Observer<T>, SnapshotObservable and RestoreObservable in the Nest\Domain\Responses directory. Couldn't find better place.

So I guess we can start review, let me know in case you will find some issues :)

[robertlyson]

Hello,

Finally, I've added several unit tests for this feature - it has been done by means of introduction of Humble Object.

I think the PR can be reviewed right now, so feel free to put your comments :)

[Mpdreamz]

Small nags,

• spaces instead of tabs (please use editorconfig)
• Observer too generic, introduced SnapshotObserver() and RestoreObserver() in the same vain as the already existing ReindexObserver()

other then that amazing work @robertlyson ! 👍 Love the unit tests and thank you for creating a proper integration test as well, made reviewing this so much easier. Really appreciated.