Metricbeat kubernetes module can’t connect to kubelet - kubernetes

Question

We have a setup, where Metricbeat is deployed as a DaemonSet on a Kubernetes cluster (specifically -- AWS EKS).
All seems to be functioning properly, but the kubelet connection.
To clarify, the following module:
- module: kubernetes
enabled: true
metricsets:
- state_pod
period: 10s
hosts: ["kube-state-metrics.system:8080"]
works properly (the events flow into logstash/elastic).
This module configuration, however, doesn't work in any variants of hosts value (localhost/kubernetes.default/whatever):
- module: kubernetes
period: 10s
metricsets:
- pod
hosts: ["localhost:10255"]
enabled: true
add_metadata: true
in_cluster: true
NOTE: using cluster IP instead of localhost (so that it goes to
control plane) also works (although doesn't retrieve the needed
information, of course).
The configuration above was taken directly from the Metricbeat
documentation and immediately struck me as odd -- how does localhost
get translated (from within Metricbeat docker) to corresponding
kubelet?
The error is, as one would expect, in light of the above:
error making http request: Get http://localhost:10255/stats/summary:
dial tcp [::1]:10255: connect: cannot assign requested address
which indicates some sort of connectivity issue.
However, when SSH-ing to any node Metricbeat is deployed on, http://localhost:10255/stats/summary provides the correct output:
{
"node": {
"nodeName": "...",
"systemContainers": [
{
"name": "pods",
"startTime": "2018-12-06T11:22:07Z",
"cpu": {
"time": "2018-12-23T06:54:06Z",
...
},
"memory": {
"time": "2018-12-23T06:54:06Z",
"availableBytes": 17882275840,
....
I must be missing something very obvious. Any suggestion would do.
NOTE: I cross-posted (and got no response for a couple of days) the same on Elasticsearch Forums

Answer 1

Inject the Pod's Node's IP via the valueFrom provider in the env: list:
env:
- name: HOST_IP
valueFrom:
fieldRef: status.hostIP
and then update the metricbeat config file to use the host's IP:
hosts: ["${HOST_IP}:10255"]
which metricbeat will resolve via its environment variable config injection