Metrics Server Addon

[deltasquare4]

Feature Request

Feature

Replace Heapster addon with metrics-server.

Tradeoffs

Heapster is deprecated, and Typhoon has already decided to replace it with metrics-server addon. I have been trying to do it with the intention to contribute back the addon to Typhoon. The problem is, metrics-server seems to require --requestheader-client-ca-file flag on the apiserver, which Typhoon doesn't allow as commented in #338.

@dghubble Can you please outline how metrics-server aggregated API can authenticate without adding support for authenticating proxy?

[dghubble]

I evaluated metrics server back in May. It requires the aggregation API and I still have concerns around that. Fast forward a few months and the aggregation server was at the root of CVE-2018-1002105.

Aggregation APIs' complexity and attack surface just don't seem worth it for addons like metrics server, its a "nice to have" addon that makes kubectl top work. Meanwhile, the provide heapster addon works fine and has no such aggregation requirement.

If the metrics server addon or aggregation becomes compelling to me, I'll add them then, but its not on my roadmap atm.

[mabushey]

How can you do autoscaling w/o metrics server? Heapster is dead.

[jmreicha]

Heapster is deprecated in k8s 1.13.

Users are encouraged to use metrics-server instead, potentially supplemented by a third-party monitoring solution, such as Prometheus.

[mabushey]

@jmreicha That's exactly my point. Typhoon only supports heapster, NOT metrics-server.

[jmreicha]

@mabushey I agree with you, I would also like to see support for metrics-server added 😁

[mabushey]

@dghubble The 0.3.x versions of Metrics Server are now using Webhook for it's authorizationMode, so some of what you looked at before has probably changed.