Observability with service mesh in Kubernetes - Commands & Configuration

Introduction

When you run many small services together, it can be hard to see how they talk and work. A service mesh helps by adding tools that watch and report on these connections automatically.

When you want to see detailed traffic flow between your microservices without changing their code

When you need to find slow or failing services quickly in a complex app

When you want automatic collection of logs, metrics, and traces from your services

When you want to control and secure service communication with visibility

When you want to add observability features without adding extra work to your developers

Config File - istio-demo.yaml

istio-demo.yaml

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: my-gateway
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: my-service
spec:
  hosts:
  - "my-service"
  gateways:
  - my-gateway
  http:
  - route:
    - destination:
        host: my-service
        port:
          number: 80

This file sets up an Istio Gateway to allow external traffic and a VirtualService to route that traffic to your service named my-service. The Gateway listens on port 80 for HTTP requests. The VirtualService tells Istio how to send requests to the service inside the mesh.

Commands

This command creates the Gateway and VirtualService in your Kubernetes cluster to enable traffic routing and observability features.

Terminal

kubectl apply -f istio-demo.yaml

Expected Output

gateway.networking.istio.io/my-gateway created

virtualservice.networking.istio.io/my-service created

Check that the Istio components, including the observability tools, are running properly in the istio-system namespace.

Terminal

kubectl get pods -n istio-system

Expected Output

NAME                                    READY   STATUS    RESTARTS   AGE

istio-ingressgateway-5d8f7f6f7b-abcde  1/1     Running   0          10m

istiod-7f9d8f7f7b-xyz12                 1/1     Running   0          10m

Find the external IP or port to access your services through the Istio ingress gateway.

Terminal

kubectl get svc istio-ingressgateway -n istio-system

Expected Output

NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)                                      AGE

istio-ingressgateway   LoadBalancer   10.96.123.45    34.68.123.45    80:31380/TCP,443:31390/TCP                    10m

Open the Kiali dashboard, a visual tool that shows service mesh traffic and observability data in your browser.

Terminal

istioctl dashboard kiali

Expected Output

Starting Kiali dashboard proxy on http://localhost:20001

Press Ctrl+C to exit

Key Concept

If you remember nothing else from this pattern, remember: a service mesh adds automatic observability by managing and reporting on service communication without changing your app code.

Common Mistakes

Not installing the service mesh control plane before applying Gateway and VirtualService resources

The resources depend on the control plane to work; without it, they won't be recognized or function.

Install Istio or your chosen service mesh first using its official installation commands before applying configuration files.

Trying to access services without exposing the ingress gateway service externally

Without an external IP or port, you cannot reach your services from outside the cluster.

Ensure the ingress gateway service is of type LoadBalancer or NodePort and note its external IP or port.

Ignoring the namespace when checking pods or services

Istio components run in the istio-system namespace; commands without -n istio-system will not find them.

Always specify the correct namespace with -n istio-system when managing Istio resources.

Summary

Apply Gateway and VirtualService YAML files to configure traffic routing and observability.

Verify Istio system pods are running to ensure observability tools are active.

Check the ingress gateway service to find how to access your mesh-enabled services.

Use the Istio Kiali dashboard to visually monitor service communication and health.