Docs: Expose the Etcd Metrics Endpoint

[MartenM]

Bug Report

When following the guide for a non production cluster the guide for exposing the etcd metrics endpoints doesn't seem correct.

cat << EOF > etcd-metrics-patch.yaml
- op: add
path: /cluster/etcd/extraArgs
value:
    listen-metrics-urls: http://0.0.0.0:2381
EOF

This YAML doesn't seem correct. When corrected to a valid YAML patch the following error gets thrown:

JSON6902 patches are not supported for multi-document machine configuration

Changing it to:

cluster:
  etcd:
    extraArgs:
      listen-metrics-urls: http://0.0.0.0:2381

Then running the following command does work:

talosctl patch machineconfig \
  --patch @etcd-metrics-patch.yaml \
  --endpoints $CP_IPS \
  --nodes $CP_IPS \
  --talosconfig=./talosconfig
patched MachineConfigs.config.talos.dev/v1alpha1 at the node 192.168.178.237
Applied configuration without a reboot

Description

This is a documentation issue I think. I would submit a PR for it, but I cannot find the right repository :(

Logs

N/A

Environment

Based on the current guide for getting a (non-production) cluster started. Latest Talos version and tools.

[smira]

@MartenM the repository is https://github.com/siderolabs/docs