"Docker and WebAssembly: A Love Story ❤️ of Two Technologies Destined to be Together "
Tags: containers, webassembly, awscommunitybuilders
Published: 2023-03-11 22:28:42

> 🚀 “Say goodbye to the old ways of deploying web apps and hello to the dynamic duo of Docker and WebAssembly! Faster, more secure, and endlessly portable. ”


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/17ybgoryjk0ynfmuazzv.png)

In recent years, both Docker and WebAssembly (WASM) have gained significant popularity in the tech community. Docker provides a way to package applications and their dependencies into lightweight containers that can be deployed and run consistently across different environments. Meanwhile, WebAssembly is a new kind of bytecode that allows developers to run compiled code in the browser at near-native speeds, opening up new possibilities for high-performance web applications. When combined, these two technologies can provide a powerful platform for building and deploying modern web applications that are portable, scalable, and secure.

So, how do Docker and WebAssembly work together? One way is by using Docker to package and deploy WebAssembly applications. Because WebAssembly can be compiled from a variety of languages, it’s possible to build complex applications that run entirely in the browser, without the need for a traditional server-side backend. 

Integration between Docker and WebAssembly has been made possible through the use of a tool called WASI (WebAssembly System Interface). WASI provides a standardized interface between WebAssembly modules and the host operating system, allowing developers to write code that can be executed both in the browser and in the Docker container. This makes it possible to build applications that can be deployed in a variety of environments, from desktops and servers to mobile devices and even IoT devices.

One of the main benefits of using Docker and WebAssembly together is portability. Docker containers are designed to be lightweight and easily transportable, making it easy to move an application from one environment to another without having to worry about dependencies or compatibility issues. Meanwhile, WebAssembly modules can be written in a variety of languages, including C, C++, Rust, and even Python, which opens up new possibilities for building web applications that are not limited to JavaScript.

Another benefit of using Docker and WebAssembly together is performance. WebAssembly modules can be compiled to run at near-native speeds, which makes it possible to build high-performance web applications that can compete with native desktop applications. Docker containers provide a way to isolate and optimize the execution environment for a specific application, which can further improve performance and scalability.

To demonstrate the power of Docker and WebAssembly integration, let’s walk through a simple example.  

**1. Write a C program that prints "Hello, world!" to the console.**
```C++
#include <stdio.h>

int main() {
    printf("Hello, world!\n");
    return 0;
}
```
**2. Compile the program to WebAssembly using Emscripten.**
```C++
emcc hello.c -o hello.wasm
```
**3. Create a Dockerfile that defines the container environment and copies the WebAssembly module into the container.**

```docker
FROM ubuntu:latest

WORKDIR /app

COPY hello.wasm .

CMD ["wasmtime", "hello.wasm"]
```
**4. Build the Docker container using the Docker build command.**

```docker
docker build -t wasm-demo .
```
**5. Run the Docker container using the Docker run command.**
```docker
docker run wasm-demo
```
**6. Verify that the "Hello, world!" message is printed to the console.**

In this demo, we've created a simple C program that prints "Hello, world!" to the console, and compiled it to WebAssembly using the Emscripten toolchain. We've also created a Dockerfile that defines the container environment and copies the WebAssembly module into the container. Finally, we've built and run the Docker container to execute the WebAssembly module and print the "Hello, world!" message to the console.

The impact of using Docker and WebAssembly together in web development is significant. By enabling high-performance web applications that can be deployed anywhere, developers can build more powerful and scalable web applications than ever before. With the ability to package applications into lightweight and portable containers, deployment and scaling become much simpler, allowing developers to focus on building great applications instead of worrying about infrastructure.

In conclusion, integrating Docker and WebAssembly can provide significant benefits in terms of portability, performance, security, productivity, and collaboration. By leveraging the strengths of these two technologies, developers can create high-performance, secure, and portable web applications that can run anywhere. Whether you are building a new web application from scratch or optimizing an existing one, it is worth considering the potential benefits of integrating Docker and WebAssembly.