k8s-app/prometheus/kube-prometheus-0.9.0/docs/GKE-cadvisor-support.md

Kubelet / cAdvisor special configuration updates for GKE

Prior to GKE 1.11, the kubelet does not support token authentication. Until it does, Prometheus must use HTTP (not HTTPS) for scraping.

You can configure this behavior through kube-prometheus with:

local kp = (import 'kube-prometheus/kube-prometheus.libsonnet') +
    (import 'kube-prometheus/kube-prometheus-insecure-kubelet.libsonnet') +
	{
        _config+:: {
		# ... config here
		}
    };

Or, you can patch and re-apply your existing manifests with:

On linux:

sed -i -e 's/https/http/g' manifests/prometheus-serviceMonitorKubelet.yaml

On MacOs:

sed -i '' -e 's/https/http/g' manifests/prometheus-serviceMonitorKubelet.yaml

After you have modified the yaml file please run

kubectl apply -f manifests/prometheus-serviceMonitorKubelet.yaml