How Oxy uses hooks for maximum extensibility

We recently introduced Oxy, our Rust framework for building proxies. Through a YAML file, Oxy allows applications to easily configure listeners (e.g. IP, MASQUE, HTTP/1), telemetry, and much more. However, when it comes to application logic, a programming language is often a better tool for the job. That’s why in this post we’re introducing Oxy’s rich dependency injection capabilities for programmatically modifying all aspects of a proxy.

The idea of extending proxies with scripting is well established: we've had great past success with Lua in our OpenResty/NGINX deployments and there are numerous web frameworks (e.g. Express) with middleware patterns. While Oxy is geared towards the development of forward proxies, they all share the model of a pre-existing request pipeline with a mechanism for integrating custom application logic. However, the use of Rust greatly helps developer productivity when compared to embedded scripting languages. Having confidence in the types and mutability of objects being passed to and returned from callbacks is wonderful.

Oxy exports a series of hook traits that “hook” into the lifecycle of a connection, not just a request. Oxy applications need to control almost every layer of the OSI model: how Continue reading