windows_exporter/kubernetes/kubernetes.md

windows_exporter on Kubernetes

With Kubernetes supporting HostProcess containers on Windows nodes (as of v1.22, it is useful to run the windows_exporter as a container on Windows to export metrics for your Prometheus implementation. Read the Kubernetes HostProcess documentation for more information.

Requirements:

• Kubernetes 1.22+
• containerd 1.6 Beta+
• WindowsHostProcessContainers feature-gate turned on for kube-apiserver and kubelet

IMPORTANT: This does not work unless you are specifically targeting Host Process Containers with Containerd (Docker doesn't have support). The image will build but will not be able to access the host.

Container Image

The image is a HostProcess container image based on mcr.microsoft.com/oss/kubernetes/windows-host-process-containers-base-image. One image works on every Windows version that supports HostProcess containers. The released images are listed in the Docker section of the readme.

To build your own image, use docker buildx on Linux, for example in WSL. The image only copies the binary, so it builds on Linux although it's a Windows image. Put the amd64 binary into an otherwise empty directory as windows_exporter-<version>-amd64.exe, the name the CI build uses, and build the image from that directory:

GOOS=windows GOARCH=amd64 go build -o output/windows_exporter-dev-amd64.exe ./cmd/windows_exporter
docker buildx build --platform windows/amd64 -f Dockerfile -t <your repository>/windows-exporter:dev --push output

Kubernetes Quick Start

Before beginning you need to deploy the Prometheus Operator to your cluster. As a quick start, you can use a project like https://github.com/prometheus-operator/kube-prometheus. The export itself doesn't have any dependency on the Prometheus Operator and the exporter image can be used in manual configurations.

Windows Exporter DaemonSet

This creates a pod on every Windows node. A ConfigMap holds the configuration of the Windows exporter with configuration file. Adjust the configuration file for the collectors you are interested in.

kubectl apply -f kubernetes/windows-exporter-daemonset.yaml

Note: This example manifest deploys the latest bleeding edge image ghcr.io/prometheus-community/windows-exporter:latest built from the main branch. You should update this to use a released version which you can find at https://github.com/prometheus-community/windows_exporter/releases

Configuring the firewall

The firewall on the node needs to be configured to allow connections on the node: New-NetFirewallRule -DisplayName 'windows-exporter' -Direction inbound -Profile Any -Action Allow -LocalPort 9182 -Protocol TCP

You could do this by adding an init container but if you remove the deployment at a later date you will need to remove the firewall rule manually. The following could be added to the windows-exporter-daemonset.yaml:

apiVersion: apps/v1
kind: DaemonSet
spec:
  template:
    spec:
      initContainers:
        - name: configure-firewall
          image: mcr.microsoft.com/windows/powershell:lts-nanoserver-1809
          command: ["powershell"]
          args: ["New-NetFirewallRule", "-DisplayName", "'windows-exporter'", "-Direction", "inbound", "-Profile", "Any", "-Action", "Allow", "-LocalPort", "9182", "-Protocol", "TCP"]

Prometheus PodMonitor

Create the Pod Monitor to configure the scraping:

kubectl apply -f kubernetes/windows-exporter-podmonitor.yaml

View Metrics

Open Prometheus with

kubectl --namespace monitoring port-forward svc/prometheus-k8s 9091:9090

Navigate to the Prometheus UI and add a query to see the node CPU (replace the IP address with yours)

sum by (mode) (irate(windows_cpu_time_total{instance="10.1.0.5:9182"}[5m]))

Configuring TLS

It is possible to configure TLS of the solution using --web.config.file. Read more at https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md