Understanding the Istio components

Similar to a standard Kubernetes cluster, Istio refers to two separate planes, the control plane and the data plane. Historically, the data plane included 4 different services, Pilot, Galley, Citadel, and Mixer – all broken out in a true microservices design. This design was used for multiple reasons including the flexibility to break out the responsibilities to multiple teams, the ability to use different programming languages, and to scale each service independently of the others.

Istio has evolved quickly since its initial release. The team made the decision that breaking out the core services had little benefit, and in the end, made Istio more complex. This led the team to redesign Istio and starting with Istio 1.5, Istio includes the components that we will discuss in this section.

Making the Control Plane Simple with Istiod

Just as Kubernetes bundled multiple controllers into a single executable, the kube-controller-manager...