[EKS] [request]: Allow feature gates to be set on master components

[jammerful]

Tell us about your request
I would like to be able to set feature gates on master components such as the kube-apiserver, this would allow me to enable features early.

Which service(s) is this request for?
EKS

Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?
Right now I can't enable feature gates on any master components, while I have a particular feature gate in mind I would like the general ability to toggle feature flags upon creating/updating a cluster. I understand that the feature gates enable alpha features, so I would simply note in the documentation and a warning upon any feature flag being set that using this feature can make your cluster unstable and all feature gates set should be throughly tested before releasing to production.

The particular feature gate is the VolumeSnapshotDataSource which is needed for the EBS CSI Driver's snapshotting feature.

Are you currently working around this issue?
I will deploy my own container to do the snapshotting myself.

[lanefu]

@jammerful hey I'm working on similar issue.... would you be able to explain your workaround a little more in-depth? What container are you deploying?

[jammerful]

@lanefu I'm assuming you want the volume snapshot feature, if you're trying to enable a random feature gate I don't think you can do that.
For volume snapshots, you can use the now deprecated external storage code located here https://github.com/kubernetes-incubator/external-storage/tree/master/snapshot. I've been using it for the past few weeks, and it's working well. In the repo you will find the manifest to deploy and instructions on how to use the CRDs.
Lastly, snapshotting in the CSI is beta in 1.17, so maybe by next spring/summer will be available on EKS.

[rinrailin]

Another good feature gate to be able to enable is VolumeSubpathEnvExpansion which is in GA for k8s v1.17 but in alpha for k8s v1.14

[dgarbus]

Shouldn't the label be EKS rather than ECS?

[jammerful]

@ellenthsu Please remove the ECS label and add the EKS label.

[jammerful]

Apparently alpha feature gates are not enabled on the stable channels of AKS or GKE, but they do have unstable channels that enable beta feature gates. Given that I don't know if AWS would consider doing this for production clusters, wish they would speak up.

[ellenthsu]

@ellenthsu Please remove the ECS label and add the EKS label.

done

[chris-vest]

I'm wanting to enable the ProcMountType feature gate in order to run Docker rootless, without having to use privileged pods.

[tokiwong]

I would like this feature to enable ServerSideApply

[spanky-medal]

We're looking for ServiceNodeExclusion since at scale, we can hit an AWS NLB service limit of 500 targets. The services we scale will not be used via the NLB (they're queue-based) so they just fill up NLB slots for no reason.