KEDA CLI Commands

[jeffhollan]

Related closely to #167 I think, but would be nice for the insights that the dashboard provides through some CLI (maybe the func CLI, not sure if KEDA needs its own).

It's possible that the dashboard won't surface much more than the kubectl would, but just had an ask from some users that it was hard to know after deploying if things were working or not. Ideally an experience a bit more than just kubectl logs existed.

[yaron2]

If I understand correctly, the ask is "how do I monitor KEDA and know if something went wrong with scaling my deployment".

Either cli or ui, currently we have two sources of truth: the controller logs and the status fields of ScaledObjects.

I can assume for the cli a command like keda get all would show the names of scaled objects, the trigger, and the latest status.

We could also parse the logs of the controller but that is not advisable.
Instead, we should make sure every ScaledObject is updated with human readable info regarding its state.

wdyt?

[yaron2]

Relates to #51

[yaron2]

Actually,

This is very similar to how you would get visibility into a service mesh.

In that case, I think the correct way to go would be to expose a Restful API from the controller to get detailed view of all the scaled objects.

The UI will visualize that data.

A KEDA cli would mean Azure Functions/kubeless/openFaaS/other users would need to have two clis in place. One for their framework and one for KEDA.

If we put that functionality in the func cli, we miss out on all non azure function users.

[ahmelsayed]

What kind of information are you thinking about surfacing from keda directly?

We could have a simple kubectl plugin and get kubectl keda .... style commands? It could wrap kubectl or communicate with that API depending on what data we're interested in showing. Most of the state we have is already stored in the crd for each scaled object.

[yaron2]

Yep a kubectl plugin is a good idea - it would communicate with our API that feeds the dashboard as well as direct user queries for more advanced cases.

[tomkerkhove]

v1.0 has shipped (:tada:) and I'd love to get working on this for v1.x so we can build the dashboard on top of this.

Anybody who agrees? If so, I can spec it a bit out and provide a proposal.

Given everything gets a dedicated repo, I'd say this should be moved to http://github.com/kedacore/cli once we've agreed on it.

[tomkerkhove]

Bumping

[arschles]

As I mentioned in #1661, I think there's another possible use case for a keda CLI or kubectl plugin, and that is to provide users a more convenient way to create ScaledObject / ScaledJobs (I added a use cases section over in #1661 for those interested). So a CLI could potentially do mutation operations as well.

What do folks think? I can work on this

[coderanger]

I don't think this would be a good user experience to encourage. The use of existing tools like Kubectl's generators is highly correlated with new user confusion about how to maintain things over time. They are great for quick demos but terrible for long-term UX :-(

[zroubalik]

I tend to agree with @coderanger.

And there are other aspects, for example from maintenance POV: let' say we implement this kind of CLI, then it should definitely support ScaledObject creation -> thus it should be able to create a Trigger definition, suggest mandatory and optional fields and validate them on the client side. And because the triggers specs are not some CRDs with a well defined structure, but just key value map, you will need to implement the validation checks for all scalers (that's already done in each scaler code) and then track all the changes/additions. It is of course doable (or refactor the existing validation part in the scaler and expose it), but not sure if it is worth the effort. 🤷‍♂️

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

[tomkerkhove]

This is out-of-scope for KEDA but happy to share when the community builds something similar