How to check application monitoring

Build the image and deploy demo-app, Service and VMServiceScrape.

When application monitoring is configured on a cluster, you can check its operation using any application with metrics in the OpenMetrics format. The instructions use a demo application from VictoriaMetrics.

Before checking, make sure that application requirements are met and VMSingle and VMAgent are deployed in user-monitoring - see application monitoring setup.

What is created in demo-app #

Prerequisites #

• host/machine/computer with git and docker installed - for downloading sources and building the demo-app image;
• local or public registry for publishing the assembled image:
  • in a closed loop — local mirror (for example, mirror.shturval.local);
  • in an open loop — for example, hub.docker.com.

Step 1. Create namespace demo-app #

In the cluster GUI, open Namespaces and create demo-app for the VictoriaMetrics demo application.

Step 2. Build and publish the image #

From the CLI, clone the repository, build the image, and push it to your registry:

Example:

git clone https://github.com/VictoriaMetrics/demo-app
cd demo-app/
REGISTRY=<YOUR VALUE> TAG=<YOUR VALUE> make docker-push

Step 3: Deploy the application and VMServiceScrape #

In the GUI, using import manifests, import Deployment, Service and VMServiceScrape into the cluster in the demo-app namespace without changing the parameters (except for the image in Deployment - specify the registry and tag from step 2):

1. Deployment demo-app - container with the demo-app image;
2. Service demo-app — port http for scrape;
3. VMServiceScrape demo-app-service-scrape - metrics collection rule for VMAgent.

Example manifests:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo-app
  namespace: demo-app
  labels:
    app.kubernetes.io/name: demo-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: demo-app
  template:
    metadata:
      labels:
        app.kubernetes.io/name: demo-app
    spec:
      containers:
        - name: app
          image: r.shturval.tech/victoriametrics/demo-app:1.2 # replace with your REGISTRY/TAG from step 2
---
apiVersion: v1
kind: Service
metadata:
  name: demo-app
  namespace: demo-app
  labels:
    app.kubernetes.io/name: demo-app
spec:
  selector:
    app.kubernetes.io/name: demo-app
  ports:
    - port: 8080
      name: http
---
apiVersion: operator.victoriametrics.com/v1beta1
kind: VMServiceScrape
metadata:
  name: demo-app-service-scrape
  namespace: demo-app
spec:
  endpoints:
    - port: http
  selector:
    matchLabels:
      app.kubernetes.io/name: demo-app

Check #

After deployment, demo-app metrics should appear in the selected storage (local VMSingle in user-monitoring or external remoteWrite).