Extending Istio Data Plane

Istio provides various APIs to manage data plane traffic. There is one API called EnvoyFilter that we have not yet used. The EnvoyFilter API provides a means to customize the istio-proxy configuration generated by the Istio control plane. Using the EnvoyFilter API, you can directly use Envoy filters even if they are not directly supported by Istio APIs.

There is another API called WasmPlugins, which is another mechanism to extend the istio-proxy functionality WebAssembly (Wasm) support is becoming common for proxies such as Envoy to enable developers to build extensions.

In this chapter, we will discuss these two topics; however, the content on EnvoyFilter will be brief, as you have already learned about filters and plugins for Envoy in Chapter 3. Rather, we will focus on how to invoke Envoy plugins from Istio configurations. However, we will delve deeper into Wasm with hands-on activities as usual.

In this chapter we will be covering the following...