There are great use cases for WebAssembly on the server-side, especially for AI, blockchain, and big data applications. You can write functions in Rust, compile into WebAssembly, and call the managed code in Node.js applications on the server. This approach combines Rust's performance, WebAssembly's security and portability, and JavaScript's ease-of-use.
Docker setup
The easiest way to set up your dev environment is to use Docker. First, clone the starter template project.
$ git clone https://github.com/second-state/wasmedge-nodejs-starter
$ cd wasmedge-nodejs-starter
Pull a Docker image with the prerequisite software stack.
$ docker pull wasmedge/appdev_x86_64
Next run the Docker image, and mount your local workspace. This way, you can run software inside the Docker container against your local files. You can also map ports from Docker to the local machine so that you can test web applications.
$ docker run -p 3000:3000 --rm -it -v $(pwd):/app wasmedge/appdev_x86_64
(docker) $ cd /app
That's it. You can now build and deploy software from the (docker) # command line. All changes to your code will be saved in your local files regardless whether you stop or delete the Docker container.
Manual setup
Of course, not everyone wants to use Docker. In the rest of the article, we will walk through setps for a manual setup in a fresh Ubuntu Server 20.04 distribution. The whole system takes 10 minutes to set up. We will install Rust, Node.js, the WasmEdge Runtime, and the rustwasmc compiler tool.
Setup the Operating System
We recommend you use the Ubuntu 20.04 LTS or later although older Linux / MacOS / Windows would probably work too. On Ubuntu Linux, use the commands below to bring your operating system up to date with the latest developer tools.
$ sudo apt-get update
$ sudo apt install -y curl wget git
WasmEdge Runtime
The easiest way to install WasmEdge is to run the following command.
$ wget -qO- https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash
If you would like to install WasmEdge with its Tensorflow and image processing extensions (only available on Linux at this time), please run the following command. It will attempt to install Tensorflow and image shared libraries on your system.
$ wget -qO- https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash -s -- -e all
Run the following command to make the installed binary available in the current session source $HOME/.wasmedge/env
Rust
Installing Rust on your Linux machine is very easy. Just two commands. At this time, we only supports up to Rust 1.50.0.
$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
$ source $HOME/.cargo/env
$ rustup override set 1.50.0
For more options on installing Rust on different systems, please refer to the official Rust documentation.
Node.js
The best way to install Node.js on Linux is through the NVM tool. NVM allows you to use the latest Node.js, and change easily when you need to test your code on a different version of Node.js.
$ curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash
$ export NVM_DIR="$HOME/.nvm"
$ [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
$ [ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"
$ nvm install v12.18.3
$ nvm use v12.18.3
Next, use the following commands to install it as a Node.js module.
$ npm install wasmedge-core
If you are using the Tensorflow WASI API for AI-as-a-Service applications, install WasmEdge with extensions.
$ npm install wasmedge-extensions
The rustwasmc compiler toolchain
The rustwasmc tool provides an easy command to compile Rust functions into WebAssembly and it automatically generates Node.js and WasmEdge integration code. Since you already have Node.js installed, this just requires one command.
$ npm install -g rustwasmc # Append --unsafe-perm if permission denied
What’s next?
Now you have all the tools, get started with a hello world example!