Kubernetes provides a simple metrics server for CPU and memory usage for each pod and node.
Additionally, the Prometheus community has developed an improved version of the metrics server: Kube State Metrics
Now, the combination of these two is like the Swiss Army Knife.
Installing the Metrics Server
You can easily set up the metrics server via Helm. First add the helm repository of the metrics server;
helm repo add metrics-server https://kubernetes-sigs.github.io/metrics-server/
helm repo update
and install the metrics server:
helm upgrade --install --set replicas=2 metrics-server metrics-server/metrics-server
Make sure it is installed:
The metrics server was set up with two replica pods.
After this step, wait a few minutes for the metrics server to collect CPU and memory statistics from the sources (pods, nodes).
You can view metrics through
kubectl top pods or
kubectl top nodes
You can also access metrics via HTTP:
You can find other available endpoints on the metrics server here.
We can access the Metrics server endpoint via
Open the Metrics server endpoint in your browser:
Prometheus community developed Kube Health Metrics because the metrics server provides simple metrics
You may install the Kube State Metrics via Helm easily. First, add the Kube State Metrics’ helm repository;
You can easily install Kube State Metrics via Helm. First add the helm repository of the Kube State Metrics;
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update
and install Kube State Metrics:
helm upgrade --install --set replicaCount=2 kube-state-metrics prometheus-community/kube-state-metrics
Get the domain of the kube-state-metrics server:
Go into one of the pods in your cluster and get the Kube State Metrics:
I filtered the pod from the metrics.
Kube State Metrics are actually raw data from the Kubernetes API.
Prometheus/Grafana makes this data readable and queryable.
However, you can benefit from metrics without needing an additional library.
I will scale out the web-debug deployment from 2 to 3 and try to observe the change in the metrics: