ADD Ingress Controller (Nginx) + Expose metrics for Prometheus

k8s/Cluster/Ingress Controller/README.md

+## Deploy Nginx as Ingress Controller
+
+![img.png](img.png)
+Read installation guide
+* https://timtech4u.medium.com/understanding-kubernetes-ingress-resources-and-controllers-6caeb417acad
+* https://devopscube.com/install-configure-helm-kubernetes/
+##### Deploy Ingress Resource 
+```sh
+kubectl apply -f ingress-resource.yaml
+```
+#### issue for metrics
+* https://github.com/kubernetes/ingress-nginx/issues/8782
+please adjust the args parameters in the deployment 
+args:
+  - /nginx-ingress-controller
+  - '--publish-service=$(POD_NAMESPACE)/ingress-nginx-controller'
+  - '--metrics-per-host=false' <<--------
\ No newline at end of file

k8s/Cluster/Ingress Controller/ingress-resource.yaml

+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: ms-demo-ingress
+  annotations:
+          # nginx.ingress.kubernetes.io/rewrite-target: /$1
+          kubernetes.io/ingress.class: "nginx"
+spec:
+  defaultBackend:
+      service:
+        name: ms-demo-service
+        port:
+          number: 8080
+  rules:
+           #- host: my-app.com
+   - http:
+       paths:
+       - path: /
+         pathType: Prefix
+         backend:
+           service:
+             name: hello-world-two
+             port:
+               number: 8080
+       - path: /fib
+         pathType: ImplementationSpecific
+         backend:
+            service:
+              name: ms-demo-service
+              port:
+               number: 8080

k8s/Cluster/Prometheus/README.md

+# Alternative Way to install Prometheus using Helm
+
+* https://github.com/prometheus-community/helm-charts/tree/main/charts/prometheus
+```sh
+kubectl create namespace prometheus
+
+helm repo add prometheus-community https://prometheus-community.github.io/helm-charts --namespace prometheus
+helm repo update
+
+helm upgrade --install prometheus prometheus-community/prometheus -n prometheus
+```
+###### Note
+you should prepare nfs server between your nodes then create the pv (persistent volume) as a shared folder to Promdata
+* https://rudimartinsen.com/2022/01/05/nginx-nfs-kubernetes/
\ No newline at end of file

k8s/Cluster/Prometheus/configmap.yaml

@@ -23,3 +23,13 @@ data:
         static_configs:
                 # Use the service name (see docker-compose-desktop.yml) instead of localhost
         - targets: ['ms-demo-service.default.svc:8080']
+
+      - job_name: 'ms-demo-ingress'
+          # Override the global default and scrape targets from this job every 5 seconds.
+          scrape_interval: 5s
+          honor_timestamps: true
+          metrics_path: /metrics
+          scheme: http
+          static_configs:
+            # Use the service name (see docker-compose-desktop.yml) instead of localhost
+            - targets: ['ingress-controller-ingress-nginx-controller-metrics.ingress-nginx.svc:10254']

k8s/Cluster/README.md

@@ -20,6 +20,6 @@ kubectl apply -f service-monitor.yaml
 ##### Step 3
 Deploy the service to cluster with horizontal pod autoscaling
 ```sh
-kubectl apply -f app-deployment.yaml
+kubectl apply -f app-service-deployment.yaml
 kubectl apply -f hpa.yaml
 ```

k8s/Cluster/app-two-service-deployment.yaml

+apiVersion: v1
+kind: Service
+metadata:
+  name: hello-world-two
+  annotations:
+    prometheus.io/port: "hello2-metrics"
+    prometheus.io/scrape: "true"
+  labels:
+    app.kubernetes.io/part-of: hello-world-two-svc
+spec:
+  ports:
+    - port: 8080
+      protocol: TCP
+      targetPort: 8080
+      name: "hello2-metrics"
+  selector:
+    app: hello-world-two
+  type: NodePort
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: hello-world-two
+  name: hello-world-two
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: hello-world-two
+  template:
+    metadata:
+      labels:
+        app: hello-world-two
+    spec:
+      containers:
+        - image: mhdbashar/ms-demo
+          name: ms-demo
+          ports:
+            - containerPort: 8080
+          resources:
+            limits:
+              cpu: "1"
+              memory: 1Gi
+            requests:
+              cpu: 500m
+              memory: 500Mi

k8s/Cluster/service-monitor.yaml

@@ -19,3 +19,21 @@ spec:
       app.kubernetes.io/part-of: ms-demo-svc
 
 #ref: https://dev.to/apgapg/creating-a-service-monitor-in-k8s-nl8
+---
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: hello2-service-monitor
+  namespace: monitoring
+spec:
+  endpoints: #This field specifies the endpoints that Prometheus should scrape for metrics. You can specify the port, path, and other information for each endpoint.
+    - interval: 15s
+      port: hello2-metrics
+      scrapeTimeout: 14s
+      path: /actuator/prometheus
+  namespaceSelector:
+    matchNames:
+      - default
+  selector: #This field specifies how Prometheus should discover the target service to monitor. You can use labels, namespaces, and other selectors to choose the target service.
+    matchLabels:
+      app.kubernetes.io/part-of: hello-world-two-svc

k8s/Docker Desktop/README.md

@@ -17,6 +17,6 @@ docker build -t ms-demo .
 Deploy Services to Docker Desktop Kubernetes
 ```sh
 kubectl apply -f monitoring-deployment.yaml
-kubectl apply -f app-deployment.yaml
+kubectl apply -f app-service-deployment.yaml
 ```