Slack notification integration

[GaruGaru]

As proposed in #101 this add the support for notifications with slack webhooks and also add a notifier interface that allows the implementation of other providers (as proposed by @linki ) with tests for both chaoskube integration and slack specific code.

The notifier is enabled by the --slack-webhook flag, the notifier itself is also wrapped by a Notifiers struct that allow the support for multiple notifiers at once (like prometheus alert manger notification system).

Result

[linki]

@GaruGaru Thank you! That looks pretty complete. 😃

Do you mind if I push some slight changes here and there?

[GaruGaru]

Hi @linki Feel free to make as many changes as needed !

[linki]

@GaruGaru I refactored it a bit but didn't change any behaviour.

[linki]

I changed the notification interface to take a Pod directly. I hope that's ok.

NotifyTermination(pod v1.Pod) error

[GaruGaru]

Thank you for the feedback! Looks good to me, the only thing that I'm not sure about is the Notifier interface NotifyTermination method, in the future chaoskube may support node (or other resources) termination, so the NotifyTermination(pod v1.Pod) may be too specific I'd either change it to NotifyPodTermination(pod v1.Pod) or keep the NotifyTermination signature but change the parameter with a more generic one

[linki]

@GaruGaru I understand and it makes sense.

In this project I tried to keep things simple and don't think too far ahead even if it breaks the API later. So I'm in favour of NotifyPodTermination(pod v1.Pod) for now.

But honestly I'm fine with both, so let's do the version you prefer 😃

[GaruGaru]

I get your point and thank you for letting me choose the method naming :D I think that NotifyPodTermination is more coherent with the method signature.

[linki]

@GaruGaru Thank you very much!

[linki]

Released in version v0.17.0.

[GaruGaru]

Nice, Thank you very much !
We should also consider to update the Helm Chart with the new parameter in the future for the next releases, I can come up with a pull request if needed