Istio Overview and Tutorial

Introduction

• Channel Focus: The video focuses on exploring Istio, its architecture, installation, traffic management, ingress gateway, TLS certificates, observability, and service visualization.
• Topics Covered:
  1. Istio architecture and how it works.
  2. Multiple methods for Istio installation on Kubernetes.
  3. Traffic management, request routing, and canary deployment.
  4. Sidecar injection into pods.
  5. Using an ingress gateway to expose applications to the internet.
  6. Installing cert-manager and obtaining TLS certificates with LetsEncrypt.
  7. Using Prometheus and Grafana for monitoring.
  8. Visualizing the service mesh with Kiali.
  9. Using Gateway API for both service mesh and as an ingress.

What is Istio?

• Definition: An open-source service mesh to connect, manage, and secure microservices.
• Development: Created by Google, IBM, and Lyft in 2017.
• Foundations: Built on top of Envoy, a high-performance proxy.
• Functionality: Uses a sidecar container for traffic management, including routing, load balancing, service discovery, etc.
• Advanced Features: Traffic management (e.g., canary deployments, A/B testing), security (e.g., mutual TLS, RBAC), and observability (e.g., distributed tracing, metrics).

Istio Installation

• Preference: Helm installation is preferred since Istio Operator is deprecated.
• Tools: istioctl for trying out and Helm for production deploys.
• Steps:
  1. Add Helm repository.
  2. Search and configure base Helm chart.
  3. Use Terraform for reproducible deployments.
  4. Deploy Istio base and Istiod Helm chart.
  5. Ensure custom resources and Istiod pod are running.

Managing Traffic with Istio

• Namespace Creation: Create a namespace (e.g., staging) and label it for injection.
• Deployments: Two example deployments (v1 and v2) for canary testing.
• Service and Custom Resources:
  • Destination Rule: Defines backend applications (subsets) for traffic routing.
  • Virtual Service: Routes traffic to different backends dynamically (e.g., 90% to v1, 10% to v2, then scaling to 50/50, and finally 100% to v2).

Traffic Testing and Management

• Curl for Testing: Use a Curl client in Kubernetes to test traffic routing.
• Canary Deployment: Gradually shift traffic from v1 to v2 and monitor.
• Helm and Terraform: Use to configure and deploy services, rules, and gateways.
• Ingress Gateway: Expose applications to the internet and manage securely with TLS.

Custom Resources and TLS Setup

• Cert-Manager for TLS: Install Cert-Manager and configure LetsEncrypt Issuers (staging and production).
• ClusterIssuer and Certificate: Create resources for automatic certificate issuance and renewal.
• Securing API: Configure Istio Gateway to use HTTPS and install certificates.
• DNS Configuration: Update DNS to map domain to load balancer.

Monitoring with Prometheus and Grafana

• Prometheus Operator: Deploy Prometheus and Grafana to monitor Istio and applications.
• PodMonitor and ServiceMonitor: Use to track application metrics.
• Grafana Dashboards: Import pre-configured dashboards for visualizing metrics including latency, traffic, and request success rates.

Use of Kiali for Visualization

• Kiali Deployment: Install Kiali to visualize the service topology.
• Service Mesh Insights: Provides graphical representation of service interactions and statuses.
• Error Detection: Quickly identify failing services and overall mesh health.

Gateway API (Experimental)

• Alternative to Ingress: Gateway API can be used as an ingress but with some limitations.
• Service Mesh Integration: Preliminary support for incorporating Gateway API within Istio's service mesh.

Conclusion

• Importance: Istio is essential for modern microservices due to its extensive networking, security, and observability capabilities.
• Resources: Further tutorials are available for both Istio custom resources and Gateway API implementations.