Support default/secure metrics-server installation

[timoreimann]

As of today, installing metrics-server requires tweaking the configuration since the default is to reach out to nodes by DNS and use TLS. A fair number of users have asked to support the default setup including TLS, which is a highly reasonable request.

The issue has originally been discussed in digitalocean/digitalocean-cloud-controller-manager#150. Several comments describe how to run metrics-server in TLS-less mode as a workaround for now.

[timoreimann]

Required work items are referenced above.

[timoreimann]

With secure TLS usage of the kubelet API now possible (see the update to #6), the --kubelet-insecure-tls parameter is not needed anymore.

Users are down to having to specify --kubelet-preferred-address-types=InternalIP at this point, which is the last item to tackle prior to the default metrics-server configuration working out of the box.

[mbrodala]

I just set up the metrics-server with the components.yaml from the v0.3.6 release and made sure to inject the --kubelet-preferred-address-types=InternalIP flag as mentioned here. (Using kustomize and a JSON patch for this)

The cluster is running on 1.17.5-do.0 currently.

Everything seems to be running just fine and I get no errors. With kubectl top node i see some metrics. However I see no change in the DOKS dashboard as suggested in official dashboard docs:

This is my view instead:

Am I missing something?

[timoreimann]

@mbrodala is this the dashboard we integrate in the DigitalOcean cloud control panel, or a separate deployment you manage on your own?

[mbrodala]

@timoreimann this is the original dashboard provided by DOKS.

[timoreimann]

@mbrodala this may indeed be an issue on our end. I filed an internal bug report so that we can look into the matter more closely.

Thanks for bringing this to our attention. I'm going to report back to this issue once we've identified and fixed the problem.

[TonyBogdanov]

@timoreimann Any news on this?
I'm also facing the exact same issue - metrics server works properly (with the mentioned modifications) & I can see the stats using the top command, but the (built-in) dashboard isn't showing them in the UI.

[timoreimann]

The dashboard metrics are served by a different, separate sidecar, which we yet have to integrate. I created #21 to track the effort.