Like a couple of innovative technologies, different people have different viewpoints on where WebAssembly fits the technology landscape. WebAssembly (also called Wasm) is certainly the subject of much hype right now. But what is it? Is it the JavaScript Killer? Is it a new programming language for the web? Is it (as we like to say) the next wave of cloud compute?

The idea of bytecode that can run anywhere dates back to the JVM inception (as far as I know). WebAssembly is the new implementation of an old idea. While WebAssembly is meant to run in the browser, Docker recently announced its capability to run WASM code without needing containers. In this post, I want to explore how it can work. Prerequisite Running WebAssembly is a beta feature and requires using containerd.

Last week, I described the basics on how to develop and deploy a Rust plugin for Apache APISIX. The plugin just logged a message when it received the request. Today, I want to leverage what we learned to create something more valuable: write part of the response-rewrite plugin with Rust. Adding a hard-coded header Let’s start small and add a hard-coded response header. Last week, we used the on_http_request_headers() function.

Apache APISIX is built upon the shoulders of two giants: NGINX, a widespread Open Source reverse-proxyOpenResty, a platform that allows scripting NGINX with the Lua programming language via LuaJIT This approach allows APISIX to provide out-of-the-box Lua plugins that should fit most business requirements. But it always comes a time when generic plugins don’t fit your requirements. In this case, you can write your own Lua plugin.

This is the 5th post in the Start Rust focus series. Up until now, JavaScript has been the only ubiquitous language available in browsers. It has made JavaScript much more popular than its design (and its associated flaws) would have allowed. I don’t want to start a holy war about the merits of JavaScript, but IMHO, it only survived this far because of its role in browsers.