Monitoring

The monitoring of the cluster can be done using Prometheus for the metrics and Grafana for visualization.

Install services

Prometheus is an open-source systems monitoring and alerting toolkit designed for reliability and scalability. It collects and stores metrics as time series data, enabling powerful querying and visualization. Originally developed by SoundCloud, Prometheus is now a part of the Cloud Native Computing Foundation and is widely used to monitor infrastructure, applications, and containerized environments like Kubernetes.

Install Prometheus

Prometheus can be installed into the kubernetes cluster via

helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update
helm install prometheus prometheus-community/prometheus

The server is then installed but not exposed. To access to Prometheus server via a web browser first copy the configuration of the Prometheus server service into a new yaml configuration file and modify the following fields: - change metadata.name into prometheus-server-ext to avoid conflict; - change spec.type in NodePort to expose to external; - under spec.ports add the field nodePort:30001 to specify the port used to expose the Prometheus server, if not specified the assigned port will be randomized; - remove the filed clusterIP to allow automatic assignement.

kubectl get service prometheus-server -o yaml > prometheus-server-ext.yaml
vim prometheus-server-ext.yaml 
kubectl apply -f prometheus-server-ext.yaml

On Minikube

Access the Prometheus Service Using Minikube:

minikube service prometheus-server-ext --profile igwn-kube

Now the Prometheus webinterface sould be accessible via http://<server-ip>:30001 where <server-ip> is the ip (or hostname) for the host who is hosting the kubernetes cluster.

Install Grafana

Grafana can be installed into the kubernetes cluster via

helm repo add grafana https://grafana.github.io/helm-charts
helm repo update
helm install grafana grafana/grafana

The server is then installed but not exposed. To access to Grafana server via a web browser first copy the configuration of the Grafana server service into a new yaml configuration file and modify the following fields: - change metadata.name into Grafana-server-ext to avoid conflict; - change spec.type in NodePort to expose to external; - under spec.ports add the field nodePort:30002 to specify the port used to expose the Grafana server, if not specified the assigned port will be randomized; - remove the filed clusterIP to allow automatic assignement.

kubectl get service grafana -o yaml > grafana-ext.yaml
vim grafana-ext.yaml 
kubectl apply -f grafana-ext.yaml

On Minikube

Access the Grafana Service Using Minikube:

minikube service grafana-ext --profile igwn-kube

Now the Grafana webinterface sould be accessible via http://<server-ip>:30002, where <server-ip> is the ip (or hostname) for the host who is hosting the kubernetes cluster.

Clean the system

To clean the system it is sufficient to unistall the servers and deleting the service

helm delete grafana
helm delete prometheus
kubectl delete svc grafana-ext
kubectl delete svc prometheus-server-ext

using kubectl get pvc check if there are some orphan volume and delete it with kubectl delete pvc <volume-name> -n <namespace>.