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kube-prometheus

This repository collects Kubernetes manifests, Grafana dashboards, and Prometheus rules combined with documentation and scripts to provide single-command deployments of end-to-end Kubernetes cluster monitoring with Prometheus (Operator).

Prerequisites

First, you need a running Kubernetes cluster. If you don't have one, we recommend you create one with Tectonic Installer. Despite the name, Tectonic Installer gives you also the choice to create a barebones Kubernetes cluster, without CoreOS' Tectonic technology. Otherwise, you can simply make use of bootkube or minikube for local testing. Some sample contents of this repository are adapted to work with a multi-node setup using bootkube.

Monitoring Kubernetes

The manifests here use the Prometheus Operator, which manages Prometheus servers and their configuration in a cluster. With a single command we can install

  • The Operator itself
  • The Prometheus node_exporter
  • kube-state-metrics
  • The Prometheus specification based on which the Operator deploys a Prometheus setup
  • A Prometheus configuration covering monitoring of all Kubernetes core components and exporters
  • A default set of alerting rules on the cluster components' health
  • A Grafana instance serving dashboards on cluster metrics
  • A three node highly available Alertmanager cluster

Simply run:

export KUBECONFIG=<path> # defaults to "~/.kube/config"
cd contrib/kube-prometheus/
hack/cluster-monitoring/deploy

After all pods are ready, you can reach:

  • Prometheus UI on node port 30900
  • Alertmanager UI on node port 30903
  • Grafana on node port 30902

To tear it all down again, run:

hack/cluster-monitoring/teardown

Monitoring custom services

The example manifests in manifests/examples/example-app deploy a fake service exposing Prometheus metrics. They additionally define a new Prometheus server and a ServiceMonitor, which specifies how the example service should be monitored. The Prometheus Operator will deploy and configure the desired Prometheus instance and continuously manage its life cycle.

hack/example-service-monitoring/deploy

After all pods are ready you can reach the Prometheus server on node port 30100 and observe how it monitors the service as specified. Same as before, this Prometheus server automatically discovers the Alertmanager cluster deployed in the Monitoring Kubernetes section.

Teardown:

hack/example-service-monitoring/teardown

Dashboarding

The provided manifests deploy a Grafana instance serving dashboards provided via ConfigMaps. Said ConfigMaps are generated from Python scripts in assets/grafana, that all have the extension .dashboard.py as they are loaded by the grafanalib Grafana dashboard generator. Bear in mind that we are for now using a fork of grafanalib as we needed to make extensive changes to it, in order to be able to generate our dashboards. We are hoping to be able to consolidate our version with the original.

As such, in order to make changes to the dashboard bundle, you need to change the *.dashboard.py files in assets/grafana, eventually add your own, and then run make generate in the kube-prometheus root directory.

To read more in depth about developing dashboards, read the Developing Prometheus Rules and Grafana Dashboards documentation.

Reloading of dashboards

Currently, Grafana does not support serving dashboards from static files. Instead, the grafana-watcher sidecar container aims to emulate the behavior, by keeping the Grafana database always in sync with the provided ConfigMap. Hence, the Grafana pod is effectively stateless. This allows managing dashboards via git etc. and easily deploying them via CD pipelines.

In the future, a separate Grafana operator will support gathering dashboards from multiple ConfigMaps based on label selection.

WARNING: If you deploy multiple Grafana instances for HA, you must use session affinity. Otherwise if pods restart the prometheus datasource ID can get out of sync between the pods, breaking the UI

Roadmap

  • Grafana Operator that dynamically discovers and deploys dashboards from ConfigMaps
  • KPM/Helm packages to easily provide production-ready cluster-monitoring setup (essentially contents of hack/cluster-monitoring)
  • Add meta-monitoring to default cluster monitoring setup
  • Build out the provided dashboards and alerts for cluster monitoring to have full coverage of all system aspects

Monitoring other Cluster Components

Discovery of API servers and kubelets works the same across all clusters. Depending on a cluster's setup several other core components, such as etcd or the scheduler, may be deployed in different ways. The easiest integration point is for the cluster operator to provide headless services of all those components to provide a common interface of discovering them. With that setup they will automatically be discovered by the provided Prometheus configuration.

For the kube-scheduler and kube-controller-manager there are headless services prepared, simply add them to your running cluster:

kubectl -n kube-system create -f manifests/k8s/

Hint: if you use this for a cluster not created with bootkube, make sure you populate an endpoints object with the address to your kube-scheduler and kube-controller-manager, or adapt the label selectors to match your setup.

Aside from Kubernetes specific components, etcd is an important part of a working cluster, but is typically deployed outside of it. This monitoring setup assumes that it is made visible from within the cluster through a headless service as well.

Note that minikube hides some components like etcd so to see the extend of this setup we recommend setting up a local cluster using bootkube.

An example for bootkube's multi-node vagrant setup is here.

Hint: this is merely an example for a local setup. The addresses will have to be adapted for a setup, that is not a single etcd bootkube created cluster.

With that setup the headless services provide endpoint lists consumed by Prometheus to discover the endpoints as targets:

$ kubectl get endpoints --all-namespaces
NAMESPACE     NAME                                           ENDPOINTS          AGE
default       kubernetes                                     172.17.4.101:443   2h
kube-system   kube-controller-manager-prometheus-discovery   10.2.30.2:10252    1h
kube-system   kube-scheduler-prometheus-discovery            10.2.30.4:10251    1h
monitoring    etcd-k8s                                       172.17.4.51:2379   1h

Other Documentation

Install Docs for a cluster created with KOPS on AWS