<p>I set up a Kubernetes cluster. Apiserver is started on host 192.168.0.2, and I use self-signed certificate and static token as authentication. The other 2 nodes' ip are 192.168.0.3 and 192.168.0.4</p>

<p>Then I created a prometheus deployment, the config is <a href="https://raw.githubusercontent.com/prometheus/prometheus/master/documentation/examples/prometheus-kubernetes.yml" rel="nofollow noreferrer">this</a>. In prometheus dashboard, the two nodes and prometheus self are showed as "UP". However the apiserver is showed "DOWN", and the reason is "context deadline exceeded". </p>

<pre><code>kubernetes-apiservers
Endpoint    State   Labels  Last Scrape Error
https://192.168.0.2:443/metrics
DOWN    instance="192.168.0.2:443"  55.979s ago context deadline exceeded
</code></pre>

<p>I tried to curl the address (<a href="https://192.168.0.2:443/metrics" rel="nofollow noreferrer">https://192.168.0.2:443/metrics</a>) from node server with ca certificate and token. The result is ok. </p>

<p>By the way, I setup the apiserver by <code>hyperkube apiserver</code> command line instead of <code>kubelet</code>. Is this the problem? And where should I look into?</p>

<p>In prometheus log, I only found this related one.</p>

<pre><code>time="2017-01-13T10:51:28Z" level=debug msg="endpoints update" kubernetes_sd=endpoint source="endpoints.go:77" tg="&amp;config.TargetGroup{Targets:[]model.LabelSet{model.LabelSet{\"__meta_kubernetes_endpoint_port_protocol\":\"TCP\", \"__meta_kubernetes_endpoint_ready\":\"true\", \"__address__\":\"192.168.0.2:443\", \"__meta_kubernetes_endpoint_port_name\":\"https\"}}, Labels:model.LabelSet{\"__meta_kubernetes_service_label_provider\":\"kubernetes\", \"__meta_kubernetes_namespace\":\"default\", \"__meta_kubernetes_endpoints_name\":\"kubernetes\", \"__meta_kubernetes_service_name\":\"kubernetes\", \"__meta_kubernetes_service_label_component\":\"apiserver\"}, Source:\"endpoints/default/kubernetes\"}"
</code></pre>

<p>Update:</p>

<p>The reason is that I didn't set up calico on master node. It works now.</p>

<p>That sounds like a network issue as the request is timing out. Can you hit that endpoint from inside the Prometheus container?</p>
