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Release native packages

Release native packages

As you can see from the previous section, the dominant distribution method on the community is distribute C/C++ source code directly. However, this approach is not an acceptable distribution solution for developers using Rust to write Node.js native addons, because the complexity and compilation time of the Rust toolchain makes distributing the source code directly a huge ordeal for developers using these native addons.

Next I will describe several ways of distributing native addon including distribute source code directly. After this introduction, I believe you can find the most suitable native addon distribution for Rust.

1. Distribute source code

Using this approach requires the user to install build tools such as node-gyp, cmake, g++, etc. This is not a problem during the development phase, but with the popularity of Docker, installing a bunch of build toolchains in a given Docker environment is a nightmare for many teams. And if this problem is not handled well, it will increase the size of the Docker image for no reason (actually this problem can be solved by building the Docker image in a special Builder image before compiling it, but I have talked to various companies and few teams will do this).

2. Distribute only JavaScript code, download the corresponding product in postinstall phase

Some native addon build dependencies are so complex that it's not practical for the average Node developer to install a full set of build tools during the development phase. Another scenario is that the native addon itself is so complex that it can take a lot of time to compile, and the library author wouldn't want people to spend hours just installing it when using his library.

So another popular way is to use the CI tools to precompile the native addon in the CI task for each platform (win32/darwin/linux/...) and distribute only the corresponding JavaScript code, while the precompiled addon file is downloaded from the CDN/GitHub release via the postinstall script. For example, there is a popular tool in the community that does this: node-pre-gyp. This tool automatically uploads the native addon compiled in CI to a specific location based on the user's configuration, and then downloads it from the upload location during installation.

This distribution method seems flawless, but there are several problems that can't be circumvented:

  • Tools such as node-pre-gyp will add a lot of runtime irrelevant dependencies to a project.
  • No matter which CDN you upload to, it's hard to accommodate users from all over the world. Do you recall the painful memories of being stuck in postinstall for hours to download files from some GitHub release and then failing? It's true that building a binary mirror in the nearest region can partially alleviate this problem, but mirror is not synchronized/missing from time to time.
  • Not friendly to private networks. Many companies may not be able to access the extranet on their CI/CD machines (they will have a private NPM to go along with it, but if they don't there is no point in discussing it), let alone downloading native addon from some CDN.

3. The native addon for different platforms is distributed through different npm packages

The new generation build tool esbuild, which is very popular on the front-end, uses this approach. Each native addon corresponds to an npm package, and then the postinstall script installs the native addon package for the current system.

Another way is to expose the packages to be installed by the user, use all native packages as optionalDependencies, and then use the os and cpu fields in package.json to have npm/yarn/pnpm automatically select them during automatically choose which native package to install (which actually fails if it doesn't match the system requirements) when installing, e.g.:

{
"name": "@node-rs/bcrypt",
"version": "0.5.0",
"os": ["linux", "win32", "darwin"],
"cpu": ["x64"],
"optionalDependencies": {
"@node-rs/bcrypt-darwin": "^0.5.0",
"@node-rs/bcrypt-linux": "^0.5.0",
"@node-rs/bcrypt-win32": "^0.5.0"
}
}
{
"name": "@node-rs/bcrypt-darwin",
"version": "0.5.0",
"os": ["darwin"],
"cpu": ["x64"]
}
{
"name": "@node-rs/bcrypt-linux",
"version": "0.5.0",
"os": ["linux"],
"cpu": ["x64"]
}
{
"name": "@node-rs/bcrypt-win32",
"version": "0.5.0",
"os": ["win32"],
"cpu": ["x64"]
}

This approach is the least intrusive distribution for users using native addon, and is used by @ffmpeg-installer/ffmpeg.

However, this approach imposes an additional workload on the native addon authors, including the need to write tools to manage the release binary and a bunch of packages, which are generally very difficult to debug (and typically span several systems and CPU architectures).

These tools need to manage the entire addon flow through the development -> local release version -> CI -> artifacts -> deploy phase. On top of that, there are a lot of CI/CD configurations to write/debug, which is time consuming and tedious.

Conclusion

The native addon with the 3rd distribution method (distribution of native addons for different platforms via different npm packages) is the easiest to use and the least mentally taxing for the developers who use it, but this distribution method imposes additional maintenance costs on the native addon authors.

Later we will describe how napi-rs can help native addon developers solve the problem of high CI/CD maintenance costs with this distribution.

You can go to recipes/publish-package chapter for more details.

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