prebuild

A command line tool for easily making prebuilt binaries for multiple versions of Node.js, N-API, Electron and NW.js on a specific platform.

$ npm install -g prebuild

Features

• Builds native modules for any version of Node.js, N-API, Electron or NW.js, without having to switch between different versions to do so. This works by only downloading the correct headers and telling node-gyp to use those instead of the ones installed on your system.
• Upload (--upload) prebuilt binaries to GitHub.
• Support for stripping (--strip) debug information. Strip command defaults to strip but can be overridden by the STRIP environment variable.
• Install prebuilt modules via prebuild-install.

Building

Building is only required for targets with different ABI versions. To build for all supported ABI versions (example from leveldown):

prebuild --all

Supported ABI versions may change over time without a new prebuild release.

Alternatively, to build for some specific versions you can do:

prebuild -t 0.10.42 -t 0.12.10 -t 4.3.0

To build for N-API, do:

prebuild -t 3 -r napi

To build against Electron headers, do:

prebuild -t 1.4.10 -r electron

To build against NW.js headers, do:

prebuild -t 0.26.6 -r node-webkit

See allTargets for all available versions.

For more options run prebuild --help. The prebuilds created are compatible with node-pre-gyp

If you'd like to include other files with your prebuilds like additional .node files or other native libraries, you can pass a file-matching regular expression to --include-regex:

prebuild -t 8.0.0 --include-regex "\.(node|a)$"

Note that if you include multiple .node files, you will need to use the prebuild-install's --binary-name parameter to indicate which file should be loaded:

prebuild-install --binary-name main-binary.node

The build file format is selected automatically by node-gyp, however it is possible to specify needed format explicitly with --format parameter. This is particularly useful if unusual flavor is required, which could be specified in 'format-flavor' form (there is no comprehensive list of formats/flavors available so one has to find possible combinations from node-gyp source code). For example, in order to build using Makefiles but assume Android cross-compilation:

prebuild --format make-android

When using the cmake-js backend additional parameters can be passed through.

prebuild --backend cmake-js -- --prefer-clang --CDUV_INCLUDE_DIR=...

Scripts

A prepack script can be specified that is executed once the .node module has been created but before it is compressed and moved. This can be used to perform code signing.

prebuild --prepack 'codesign -v -s MyCompany'

The --preinstall or --prepack parameters can take either a shell command or JS file to be executed.

Uploading

prebuild supports uploading prebuilds to GitHub releases. If the release doesn't exist, it will be created for you. To upload prebuilds simply add the -u <github-token> option:

$ prebuild --all -u <github-token>

If you don't want to use the token on cli you can put it in ~/.prebuildrc:

upload=<github-token>

Note that --upload will only upload the targets that was built and stored in ./prebuilds, so prebuild -u <github-token> -t 4.3.0 will only upload the binary for the 4.3.0 target.

You can use prebuild --upload-all to upload all files from the ./prebuilds folder.

You can use prebuild --upload --tag-prefix <prefix> for specific tag prefixes for the release. The default prefix is v and will result in a tag with an appended version number, for example v1.0.0. For lerna you can use the package name e.g. prebuild --tag-prefix some-package@ and the binaries will be released on the appropriate package's tags, for example [email protected].

Create GitHub Token

A GitHub token is needed for two reasons:

• Create a GitHub release (leveldown example)
• Upload the prebuilt binaries to that release

To create a token:

• Go to this page
• Click the Generate new token button
• Give the token a name and click the Generate token button, see below

The default scopes should be fine.

N-API Considerations

Declaring Supported N-API Versions

Native modules that are designed to work with N-API must explicitly declare the N-API version(s) against which they can build. This is accomplished by including a binary property on the module's package.json file. For example:

"binary": {
  "napi_versions": [2,3]
}

In the absence of a need to compile against a specific N-API version, the value 3 is a good choice as this is the N-API version that was supported when N-API left experimental status.

Modules that are built against a specific N-API version will continue to operate indefinitely, even as later versions of N-API are introduced.

Defining the NAPI_VERSION Value

The N-API header files supplied with Node use the NAPI_VERSION preprocessor value supplied by the user to configure each build to the specific N-API version for which the native addon is being built. In addition, the module's C/C++ code can use this value to conditionally compile code based on the N-API version it is being compiled against.

prebuild supports two build backends: node-gyp and cmake-js. The NAPI_VERSION value is configured differently for each backend.

node-gyp

The following code must be included in the binding.gyp file of modules targeting N-API:

"defines": [
  "NAPI_VERSION=<(napi_build_version)",
]

cmake-js

The following line must be included in the CMakeLists.txt file of modules targeting N-API:

add_compile_definitions(NAPI_VERSION=${napi_build_version})

prebuild arguments

The --runtime argument must be napi to request N-API builds. When requesting N-API builds, the module's package.json file must include a binary property as described above. And the binding.gyp file must include a define for NAPI_VERSION as described above.

One or more --target arguments may be specified to request builds for specific N-API versions. N-API versions are positive integer values. Alternatively, --all may be used to request builds for all N-API versions supported by the module.

In the absence of both --target and --all arguments, prebuild will build the most current version of the module supported by the Node instance performing the build.

Help

$ prebuild -h
prebuild [options]

  --target      -t  version     (version to build or install for)
  --runtime     -r  runtime     (Node runtime [node, napi, electron or node-webkit] to build or install for, default is node)
  --all                         (prebuild for all known abi versions)
  --upload      -u  [gh-token]  (upload prebuilds to github)
  --upload-all  -u  [gh-token]  (upload all files from ./prebuilds folder to github)
  --tag-prefix <prefix>         (github tag prefix, default is "v")
  --preinstall  -i  script      (run this script before prebuilding)
  --prepack     -c  script      (run this script before packing, can be used to codesign)
  --path        -p  path        (make a prebuild here)
  --include-regex               (regex to match files that will be distributed [default: '\.node$'])
  --libc                        (use provided libc rather than system default)
  --backend                     (specify build backend, default is 'node-gyp')
  --format                      (specify additional parameters for `node-gyp` backend)
  --strip                       (strip debug information)
  --debug                       (set Debug or Release configuration)
  --verbose                     (log verbosely)
  --version                     (print prebuild version and exit)

JavaScript API

var prebuild = require('prebuild')

.build(opts, version, cb)

Options:

• .log (optional)
• .preinstall (optional)
• .gyp Provide a custom node-gyp instance (optional)
• .backend Provide a custom node-gyp instance via string. Alternatives are 'node-gyp', 'node-ninja', 'nw-gyp' and 'cmake-js' (optional, defaults to 'node-gyp')
• .args Additional command line arguments to node-gyp (optional)
• .debug Pass in --debug on command line to gyp backend (optional)

Example:

prebuild.build({}, version, function (err) {
  // ...
})

Global options:

• .debug Download or build a debug build (default: false)
• .arch Processor architecture (default: process.arch)

Develop prebuild

If you want to hack on prebuild you need an environment to play around with. We recommend a setup similar to the following:

• A fork of prebuild
• A GitHub token (see above)
• A native node module

$ git clone [email protected]:<your-nick>/prebuild
$ cd prebuild && npm link && cd ..
$ git clone [email protected]:<your-nick>/some-native-module

Since you did npm link on prebuild it will be installed globally. Now you can go ahead and try things out.

$ cd some-native-module
$ prebuild --all --strip -u <github-token>

This command would:

• Build some-native-module for all supported targets and store them in ./prebuilds/
• Strip binaries from debug information
• Create a release on GitHub, if needed
• Upload all binaries to that release, if not already uploaded

Before you commit your changes and send us a pull request, do run npm test.

License

MIT