kubectl exec session with ELB not respecting keep-alives and session not in UI

[jon-can]

Description

What happened:
ELBs have an idle timeout: https://aws.amazon.com/blogs/aws/elb-idle-timeout-control/
This issue addresses that: #2334
However those configuration options seem to only apply to SSH sessions. If someone is kubectl exec’ing through an ELB the kubectl exec session will end depending on what the idle timeout is set to. If the kubectl exec session ends due to the timeout then there is not a recording that appears in the UI.

What you expected to happen:
kubectl exec session should not end and the session should be recorded and appear in the UI

How to reproduce it (as minimally and precisely as possible):
Used this Helm Chart with an AWS ELB:
https://github.com/gravitational/teleport/tree/master/examples/chart/teleport

AWS ELB has an idle timeout so keep_alive_interval is set to a value less than the idle timeout.

Environment

image:
repository: quay.io/gravitational/teleport-ent
tag: 4.2.8

┆Issue is synchronized with this Asana task by Unito

[russjones]

Best: 3
Worst: 5

[awly]

Sent kubernetes/kubernetes#94170 with an upstream change needed for this.
If it's not merged before 4.4 approaches, I'll make a temporary fork with the patch for us to use.

[awly]

kubernetes/kubernetes#94170 has been merged.
Now we can just bump our vendored version and enable the SPDY pings.