How To Setup Kube State Metrics on Kubernetes

Kube State Metrics is a crucial component in a Kubernetes cluster, providing valuable insights into the state of resources and objects within the cluster. Setting up Kube State Metrics ensures that you have a comprehensive understanding of your cluster's health and performance. In this guide, we'll walk through the process of setting up Kube State Metrics on Kubernetes, step by step.

Prerequisites:
Before we dive into the setup process, ensure that you have the following prerequisites in place:

1. A running Kubernetes cluster.
2. kubectl command-line tool installed and configured.

Step 1: Deploying Prometheus Operator:
Kube State Metrics is often deployed alongside Prometheus using the Prometheus Operator. Let's deploy the operator first:

kubectl create namespace monitoring
kubectl apply -f https://raw.githubusercontent.com/coreos/kube-prometheus/master/manifests/setup/prometheus-operator-0servicemonitorCustomResourceDefinition.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/kube-prometheus/master/manifests/setup/prometheus-operator-1clusterRole.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/kube-prometheus/master/manifests/setup/prometheus-operator-2clusterRoleBinding.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/kube-prometheus/master/manifests/setup/prometheus-operator-3serviceAccount.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/kube-prometheus/master/manifests/setup/prometheus-operator-4operator.yaml

These commands create the necessary resources for the Prometheus Operator in the "monitoring" namespace.

Step 2: Installing Kube State Metrics:
Now, let's deploy Kube State Metrics using the following commands:

kubectl apply -f https://raw.githubusercontent.com/kubernetes/kube-state-metrics/master/examples/standard/kubernetes/kube-state-metrics-deployment.yaml

This YAML file contains the deployment configuration for Kube State Metrics. It creates the necessary deployment, service, and service account.

Step 3: Exposing Kube State Metrics Service:
By default, the Kube State Metrics service is not exposed externally. To access it, we need to create a service and expose it. Run the following commands:

kubectl apply -f https://raw.githubusercontent.com/kubernetes/kube-state-metrics/master/examples/standard/kubernetes/kube-state-metrics-service.yaml

This will create a service of type ClusterIP, allowing internal access within the cluster.

Step 4: Verifying Kube State Metrics Deployment:
To ensure that Kube State Metrics is deployed successfully, check the pods in the "kube-system" namespace:

kubectl get pods -n kube-system | grep kube-state-metrics

You should see a pod running, indicating a successful deployment.

Step 5: Accessing Kube State Metrics Metrics:
Kube State Metrics exposes metrics on the "/metrics" endpoint. To access these metrics, you can port-forward the service to your local machine:

kubectl port-forward -n kube-system svc/kube-state-metrics 8080:8080

Now, you can access the metrics at http://localhost:8080/metrics using your web browser.

Congratulations! You've successfully set up Kube State Metrics on Kubernetes, gaining valuable insights into your cluster's state. Monitoring and understanding the health of your Kubernetes resources is crucial for maintaining a robust and efficient cluster.