Prometheus & Grafana

You can perform Kubernetes cluster monitoring and visualization by installing Prometheus and Grafana. You can collect metric data with Prometheus, create dashboards with Grafana, and monitor cluster resource statuses with kube-state-metrics.

PROMETHEUS

Prometheus is an open-source system and network monitoring tool designed for Kubernetes and microservice architectures. It collects, stores, queries, and creates graphs of performance data.

1) Prometheus Installation

The environment (namespace) to work in is created:

kubectl create namespace monitoring

Role-Based Access Control (RBAC) is created:

vi clusterRole.yaml

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: prometheus
rules:
  - apiGroups: [""]
    resources:
      - nodes
      - nodes/proxy
      - services
      - endpoints
      - pods
    verbs: ["get", "list", "watch"]
  - apiGroups:
      - extensions
    resources:
      - ingresses
    verbs: ["get", "list", "watch"]
  - nonResourceURLs: ["/metrics"]
    verbs: ["get"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: prometheus
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: prometheus
subjects:
  - kind: ServiceAccount
    name: default
    namespace: monitoring

kubectl create -f clusterRole.yaml

A ConfigMap containing Prometheus configuration settings for Kubernetes is defined:

vi config-map.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-server-conf
  labels:
    name: prometheus-server-conf
  namespace: monitoring
data:
  prometheus.rules: |-
    groups:
      - name: demo alert rules
        rules:
          - alert: High Pod Memory
            expr: sum(container_memory_usage_bytes) > 1
            for: 1m
            labels:
              severity: slack
            annotations:
              summary: High Memory Usage
  prometheus.yml: |-
    global:
      scrape_interval: 5s
      evaluation_interval: 5s
    rule_files:
      - /etc/prometheus/prometheus.rules
    alerting:
      alertmanagers:
        - scheme: http
          static_configs:
            - targets:
                - "alertmanager.monitoring.svc:9093"
    scrape_configs:
      - job_name: 'node-exporter'
        kubernetes_sd_configs:
          - role: endpoints
        relabel_configs:
          - source_labels: [__meta_kubernetes_endpoints_name]
            regex: 'node-exporter'
            action: keep
      - job_name: 'kubernetes-apiservers'
        kubernetes_sd_configs:
          - role: endpoints
        scheme: https
        tls_config:
          ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        relabel_configs:
          - source_labels: [__meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
            action: keep
            regex: default;kubernetes;https
      - job_name: 'kubernetes-nodes'
        scheme: https
        tls_config:
          ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        kubernetes_sd_configs:
          - role: node
        relabel_configs:
          - action: labelmap
            regex: __meta_kubernetes_node_label_(.+)
          - target_label: __address__
            replacement: kubernetes.default.svc:443
          - source_labels: [__meta_kubernetes_node_name]
            regex: (.+)
            target_label: __metrics_path__
            replacement: /api/v1/nodes/${1}/proxy/metrics
      - job_name: 'kubernetes-pods'
        kubernetes_sd_configs:
          - role: pod
        relabel_configs:
          - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
            action: keep
            regex: true
          - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
            action: replace
            target_label: __metrics_path__
            regex: (.+)
          - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
            action: replace
            regex: ([^:]+)(?::\d+)?;(\d+)
            replacement: $1:$2
            target_label: __address__
          - action: labelmap
            regex: __meta_kubernetes_pod_label_(.+)
          - source_labels: [__meta_kubernetes_namespace]
            action: replace
            target_label: kubernetes_namespace
          - source_labels: [__meta_kubernetes_pod_name]
            action: replace
            target_label: kubernetes_pod_name
      - job_name: 'kube-state-metrics'
        static_configs:
          - targets: ['kube-state-metrics.kube-system.svc.cluster.local:8080']
      - job_name: 'kubernetes-cadvisor'
        scheme: https
        tls_config:
          ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        kubernetes_sd_configs:
          - role: node
        relabel_configs:
          - action: labelmap
            regex: __meta_kubernetes_node_label_(.+)
          - target_label: __address__
            replacement: kubernetes.default.svc:443
          - source_labels: [__meta_kubernetes_node_name]
            regex: (.+)
            target_label: __metrics_path__
            replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor
      - job_name: 'kubernetes-service-endpoints'
        kubernetes_sd_configs:
          - role: endpoints
        relabel_configs:
          - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
            action: keep
            regex: true
          - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]
            action: replace
            target_label: __scheme__
            regex: (https?)
          - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]
            action: replace
            target_label: __metrics_path__
            regex: (.+)
          - source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]
            action: replace
            target_label: __address__
            regex: ([^:]+)(?::\d+)?;(\d+)
            replacement: $1:$2
          - action: labelmap
            regex: __meta_kubernetes_service_label_(.+)
          - source_labels: [__meta_kubernetes_namespace]
            action: replace
            target_label: kubernetes_namespace
          - source_labels: [__meta_kubernetes_service_name]
            action: replace
            target_label: kubernetes_name

kubectl apply -f config-map.yaml

Prometheus deployment and service are created:

vi prometheus-deploy.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus-deployment
  namespace: monitoring
  labels:
    app: prometheus-server
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus-server
  template:
    metadata:
      labels:
        app: prometheus-server
    spec:
      containers:
        - name: prometheus
          image: prom/prometheus
          args:
            - "--storage.tsdb.retention.time=12h"
            - "--config.file=/etc/prometheus/prometheus.yml"
            - "--storage.tsdb.path=/prometheus/"
          ports:
            - containerPort: 9090
          resources:
            requests:
              cpu: 500m
              memory: 500M
            limits:
              cpu: 1
              memory: 1Gi
          volumeMounts:
            - name: prometheus-config-volume
              mountPath: /etc/prometheus/
            - name: prometheus-storage-volume
              mountPath: /prometheus/
      volumes:
        - name: prometheus-config-volume
          configMap:
            defaultMode: 420
            name: prometheus-server-conf
        - name: prometheus-storage-volume
          emptyDir: {}

vi prometheus-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: prometheus-service
  namespace: monitoring
  annotations:
    prometheus.io/scrape: 'true'
    prometheus.io/port: '9090'
spec:
  selector:
    app: prometheus-server
  type: NodePort
  ports:
    - port: 8080
      targetPort: 9090
      nodePort: 30686

kubectl apply -f prometheus-deploy.yaml
kubectl apply -f prometheus-service.yaml

After creation, access to Prometheus is provided from http://<KUBERNETES_WORKER_IP_ADDRESS>:<NODE_PORT>.

2) KUBE-STATE-METRICS Installation

Kube-state-metrics is used to collect information about the status of resources (e.g., pods, services, replicasets) in the Kubernetes cluster.

vi cluster-role-binding.yaml

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: kube-state-metrics
    app.kubernetes.io/version: 2.3.0
  name: kube-state-metrics
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kube-state-metrics
subjects:
  - kind: ServiceAccount
    name: kube-state-metrics
    namespace: kube-system

vi cluster-role.yaml

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: kube-state-metrics
    app.kubernetes.io/version: 2.3.0
  name: kube-state-metrics
rules:
- apiGroups:
  - ""
  resources:
  - configmaps
  - secrets
  - nodes
  - pods
  - services
  - resourcequotas
  - replicationcontrollers
  - limitranges
  - persistentvolumeclaims
  - persistentvolumes
  - namespaces
  - endpoints
  verbs:
  - list
  - watch
- apiGroups:
  - apps
  resources:
  - statefulsets
  - daemonsets
  - deployments
  - replicasets
  verbs:
  - list
  - watch
- apiGroups:
  - batch
  resources:
  - cronjobs
  - jobs
  verbs:
  - list
  - watch
- apiGroups:
  - autoscaling
  resources:
  - horizontalpodautoscalers
  verbs:
  - list
  - watch
- apiGroups:
  - authentication.k8s.io
  resources:
  - tokenreviews
  verbs:
  - create
- apiGroups:
  - authorization.k8s.io
  resources:
  - subjectaccessreviews
  verbs:
  - create
- apiGroups:
  - policy
  resources:
  - poddisruptionbudgets
  verbs:
  - list
  - watch
- apiGroups:
  - certificates.k8s.io
  resources:
  - certificatesigningrequests
  verbs:
  - list
  - watch
- apiGroups:
  - storage.k8s.io
  resources:
  - storageclasses
  - volumeattachments
  verbs:
  - list
  - watch
- apiGroups:
  - admissionregistration.k8s.io
  resources:
  - mutatingwebhookconfigurations
  - validatingwebhookconfigurations
  verbs:
  - list
  - watch
- apiGroups:
  - networking.k8s.io
  resources:
  - networkpolicies
  - ingresses
  verbs:
  - list
  - watch
- apiGroups:
  - coordination.k8s.io
  resources:
  - leases
  verbs:
  - list
  - watch

kubectl apply -f cluster-role-binding.yaml
kubectl apply -f cluster-role.yaml

vi metrics-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: kube-state-metrics
    app.kubernetes.io/version: 2.3.0
  name: kube-state-metrics
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: kube-state-metrics
  template:
    metadata:
      labels:
        app.kubernetes.io/component: exporter
        app.kubernetes.io/name: kube-state-metrics
        app.kubernetes.io/version: 2.3.0
    spec:
      automountServiceAccountToken: true
      containers:
        - image: k8s.gcr.io/kube-state-metrics/kube-state-metrics:v2.3.0
          livenessProbe:
            httpGet:
              path: /healthz
              port: 8080
            initialDelaySeconds: 5
            timeoutSeconds: 5
          name: kube-state-metrics
          ports:
            - containerPort: 8080
              name: http-metrics
            - containerPort: 8081
              name: telemetry
          readinessProbe:
            httpGet:
              path: /
              port: 8081
            initialDelaySeconds: 5
            timeoutSeconds: 5
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 65534
      nodeSelector:
        kubernetes.io/os: linux
      serviceAccountName: kube-state-metrics

kubectl apply -f metrics-deployment.yaml

vi service-account.yaml

apiVersion: v1
automountServiceAccountToken: false
kind: ServiceAccount
metadata:
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: kube-state-metrics
    app.kubernetes.io/version: 2.3.0
  name: kube-state-metrics
  namespace: kube-system

vi kube-state-metric-service.yaml

apiVersion: v1
kind: Service
metadata:
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: kube-state-metrics
    app.kubernetes.io/version: 2.3.0
  name: kube-state-metrics
  namespace: kube-system
spec:
  clusterIP: None
  ports:
    - name: http-metrics
      port: 8080
      targetPort: http-metrics
    - name: telemetry
      port: 8081
      targetPort: telemetry
  selector:
    app.kubernetes.io/name: kube-state-metrics

kubectl apply -f service-account.yaml
kubectl apply -f kube-state-metric-service.yaml

For detailed information, you can review Prometheus’s own documentation page: https://prometheus.io/docs/introduction/overview/

3) Grafana Installation

Grafana is an open-source data visualization web application. You can connect to various data sources and display your data in charts and graphs and interpret it more easily.

Grafana installation on Ubuntu operating systems is described below. Deployment configuration can be used for Grafana installation on Kubernetes.

sudo wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -
echo "deb https://packages.grafana.com/oss/deb stable main" | sudo tee /etc/apt/sources.list.d/grafana.list
sudo apt update
sudo apt-get install -y grafana
sudo systemctl start grafana-server
sudo systemctl status grafana-server
sudo systemctl enable grafana-server

After installation is completed, access is provided from http://<SERVER_IP_ADDRESS>:3000.

Default login information for Grafana:

• username: admin
• password: admin

4) Adding Prometheus Connection in Grafana

A Prometheus connection information is added from the left menu.

Prometheus is selected. By clicking the “Add new data source” option, the Prometheus server URL information is entered and the connection is saved.

Grafana - Adding Prometheus data source

Click the “Dashboard” tab from the left menu. Then, a new import process is started with the “New” option.

Grafana - Dashboard import screen

Add numbers 315 and 13498 to the ID field respectively. Click the Load button. Select the Prometheus connection where the Dashboard will run and save with the “Import” option.

Dashboard ID: 315

Visually presents information such as CPU usage, memory usage, and network transaction intensity in your cluster and nodes.

Dashboard ID: 13498

Visually presents CPU usage, memory usage, and network transaction intensity information at namespace, pod, and container levels.

For detailed information, you can review Grafana’s own documentation page: https://grafana.com/docs/grafana/latest/