Summary

In this chapter, we prepared a local environment to install Istio using istioctl which is the Istio command-line utility. We then enabled sidecar injection by applying a label called istio-injection: enabled to the namespace that hosts the microservices.

We briefly looked at Kubernetes admission controllers and how mutating admission webhooks inject sidecars to the deployment API calls to the Kubernetes API server. We also read about gateways and looked at the sample Ingress and Egress gateways that are installed with Istio. The gateway is a standalone istio-proxy, aka an Envoy proxy, and is used to manage Ingress and Egress traffic to and from the mesh. Following this, we looked at how various ports are configured to be exposed on the Ingress gateway and how traffic is routed to upstream services.

Istio provides integration with various telemetry and observability tools. The first tool we looked at was Kiali, the visualization tool providing insight into traffic flows...