Deploying a Microservices Application with Istio as a Service Mesh on Rancher Kubernetes

Introduction

In modern cloud-native applications, microservices architecture is widely adopted due to its scalability and maintainability. However, managing the communication between microservices can be challenging. Istio, a popular service mesh, helps by providing traffic management, security, and observability. In this blog, we will explore how to deploy a microservices-based application with Istio on Rancher Kubernetes.

Prerequisites

To follow this guide, you need:

• A Rancher-managed Kubernetes cluster

• Kubectl and Istioctl installed

• A containerized microservices application

• Helm installed for managing Istio

Step 1: Install Istio on Rancher Kubernetes

Before deploying your application, you need to set up Istio.

1.1 Download and Install Istio

curl -L https://istio.io/downloadIstio | sh -
cd istio-1.x.x
export PATH=$PWD/bin:$PATH

1.2 Install Istio with Helm

helm install istio-base manifests/charts/base -n istio-system --create-namespace
helm install istiod manifests/charts/istio-control/istio-discovery -n istio-system

Step 2: Enable Istio Sidecar Injection

Istio uses a sidecar proxy to manage service-to-service communication.

kubectl label namespace default istio-injection=enabled

Step 3: Deploy the Microservices Application

3.1 Define Kubernetes Deployment and Service

Create deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-microservice
  labels:
    app: my-microservice
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-microservice
  template:
    metadata:
      labels:
        app: my-microservice
    spec:
      containers:
      - name: my-microservice
        image: my-microservice:latest
        ports:
        - containerPort: 8080

Create service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: my-microservice
spec:
  selector:
    app: my-microservice
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080

Apply the configurations:

kubectl apply -f deployment.yaml
kubectl apply -f service.yaml

Step 4: Deploy Istio Gateway and Virtual Service

4.1 Define Gateway

Create gateway.yaml:

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: my-microservice-gateway
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "my-microservice.example.com"

4.2 Define Virtual Service

Create virtualservice.yaml:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: my-microservice
spec:
  hosts:
  - "my-microservice.example.com"
  gateways:
  - my-microservice-gateway
  http:
  - match:
    - uri:
        prefix: "/"
    route:
    - destination:
        host: my-microservice
        port:
          number: 80

Apply the configurations:

kubectl apply -f gateway.yaml
kubectl apply -f virtualservice.yaml

Step 5: Verify Deployment

Check the services and Istio components:

kubectl get pods -n istio-system
kubectl get svc -n istio-system
kubectl get virtualservices
kubectl get gateways

Test the application:

curl -H "Host: my-microservice.example.com" http://<EXTERNAL_IP>

Conclusion

By deploying Istio as a service mesh in Rancher Kubernetes, you gain better control over microservices networking, security, and observability. With this setup, you can easily manage traffic, apply security policies, and monitor service interactions efficiently.