First, you need Bazel.
We recommend using Bazelisk, which is a version-selection wrapper, similar to
the nvm tool managing your version of Node. This is available on npm.
We also recommend installing ibazel which is the “watch mode” for Bazel.
$ yarn add -D @bazel/bazelisk @bazel/ibazel
# or
$ npm install --save-dev @bazel/bazelisk @bazel/ibazel
You could install a current bazel distribution, following the bazel instructions.
If you use Bazelisk, see this workaround to get working command-line completion.
It’s reasonable to globally-install bazelisk so you get a bazel command in your $PATH.
We don’t recommend this with ibazel as the version is frequently changing.
Next, create a WORKSPACE file in your project root (or edit the existing one)
containing:
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
name = "build_bazel_rules_nodejs",
sha256 = "4e1a5633267a0ca1d550cced2919dd4148575c0bafd47608b88aea79c41b5ca3",
urls = ["https://github.com/bazelbuild/rules_nodejs/releases/download/4.2.0/rules_nodejs-4.2.0.tar.gz"],
)
load("@build_bazel_rules_nodejs//:index.bzl", "node_repositories")
Now you can choose from a few options to finish installation.
To choose a version of Node.js:
These are described in more detail in the following sections.
Add this to your WORKSPACE file. It only tells Bazel how to find your
package.json file. It will use default versions of Node.js and npm.
# NOTE: this rule installs nodejs, npm, and yarn, but does NOT install
# your npm dependencies into your node_modules folder.
# You must still run the package manager to do this.
node_repositories(package_json = ["//:package.json"])
You can choose a specific version of Node.js that’s built into these rules. You can also choose a specific version of Yarn. Note that some of our packages have started to use features from Node 12, so you may see warnings if you use an older version.
Now that Node 12 is LTS (Long-term support) we encourage you to upgrade, and don’t intend to fix bugs which are only observed in Node 10 or lower.
The available versions are documented on the node_repositories rule in the Built-ins.
Add to WORKSPACE:
# NOTE: this rule installs nodejs, npm, and yarn, but does NOT install
# your npm dependencies into your node_modules folder.
# You must still run the package manager to do this.
node_repositories(
package_json = ["//:package.json"],
node_version = "8.11.1",
yarn_version = "1.5.1",
)
If you’d like to use a version of NodeJS and/or Yarn that are not currently supported here, you can manually
specify those in your WORKSPACE:
load("@build_bazel_rules_nodejs//:index.bzl", "node_repositories")
# NOTE: this rule does NOT install your npm dependencies into your node_modules folder.
# You must still run the package manager to do this.
node_repositories(
node_version = "8.10.0",
yarn_version = "1.5.1",
node_repositories = {
"8.10.0-darwin_amd64": ("node-v8.10.0-darwin-x64.tar.gz", "node-v8.10.0-darwin-x64", "7d77bd35bc781f02ba7383779da30bd529f21849b86f14d87e097497671b0271"),
"8.10.0-linux_amd64": ("node-v8.10.0-linux-x64.tar.xz", "node-v8.10.0-linux-x64", "92220638d661a43bd0fee2bf478cb283ead6524f231aabccf14c549ebc2bc338"),
"8.10.0-windows_amd64": ("node-v8.10.0-win-x64.zip", "node-v8.10.0-win-x64", "936ada36cb6f09a5565571e15eb8006e45c5a513529c19e21d070acf0e50321b"),
},
yarn_repositories = {
"1.5.1": ("yarn-v1.5.1.tar.gz", "yarn-v1.5.1", "cd31657232cf48d57fdbff55f38bfa058d2fb4950450bd34af72dac796af4de1"),
},
node_urls = ["https://nodejs.org/dist/v{version}/{filename}"],
yarn_urls = ["https://github.com/yarnpkg/yarn/releases/download/v{version}/{filename}"],
package_json = ["//:package.json"])
Specifying node_urls and yarn_urls is optional. If omitted, the default values will be used. You may also use a custom NodeJS version and the default Yarn version or vice-versa.
Finally, you could check Node.js and Yarn into your repository, and not fetch them from the internet. This is what we do internally at Google.
load("@build_bazel_rules_nodejs//:index.bzl", "node_repositories")
# Point node_repositories to use locally installed versions of Node.js and Yarn.
# The vendored_node and vendored_yarn labels point to the extracted contents of
# https://nodejs.org/dist/v10.12.0/node-v10.12.0-linux-x64.tar.xz and
# https://github.com/yarnpkg/yarn/releases/download/v1.10.0/yarn-v1.10.0.tar.gz
# respectively. NOTE: node-v10.12.0-linux-x64 will only work on Linux.
node_repositories(
vendored_node = "@wksp//:third_party/node-v10.12.0-linux-x64",
vendored_yarn = "@wksp//:third_party/yarn-v1.10.0",
package_json = ["//:package.json"])
In this case, the locally installed Node.js and Yarn are located in the wksp workspace in
the third_party/node-v10.12.0-linux-x64 and third_party/yarn-v1.10.0 folders. When using
vendored_node, you will be restricted to a single platform. vendored_yarn on the other hand,
is platform independent. See /examples/vendored_node in this repository for an example of this
in use.
NOTE: Vendored Node.js and Yarn are not compatible with Remote Bazel Execution.
When you add node_repositories() to your WORKSPACE file it will setup a node toolchain for all currently supported platforms, Linux, macOS and Windows. Amongst other things this adds support for cross-compilations as well as Remote Build Execution support. For more detailed information also see Bazel Toolchains.
If you have an advanced use-case you can also register your own toolchains and call node_toolchain_configure directly to manually setup a toolchain.
Toolchains allow us to support cross-compilation, e.g. building a linux binary from mac or windows. To tell Bazel to provide a toolchain for a different platform you have to pass in the --platforms flag. Currently supported values are:
@build_bazel_rules_nodejs//toolchains/node:linux_amd64@build_bazel_rules_nodejs//toolchains/node:linux_arm64@build_bazel_rules_nodejs//toolchains/node:linux_s390x@build_bazel_rules_nodejs//toolchains/node:linux_ppc64le@build_bazel_rules_nodejs//toolchains/node:darwin_amd64@build_bazel_rules_nodejs//toolchains/node:windows_amd64So if for example you want to build a docker image from a non-linux platform you would run bazel build --platforms=@build_bazel_rules_nodejs//toolchains/node:linux_amd64 //app, which will ensure that the linux nodejs binary is downloaded and provided to the nodejs_binary target.
Note: The toolchain currently only provides a platform-specific nodejs binary. Any native modules will still be fetched/built, by npm/yarn, for your host platform, so they will not work on the target platform. Support for cross-compilation with native dependencies will follow.
Because these rules use the target platform to decide which node binary to use, you will run into trouble if you are trying to invoke these rules as part of a cross-compilation to a platform that is not supported by the default node repositories, eg when trying to bundle some js products into a binary targeting Android or iOS. You can work around this by defining your own toolchain, and specifying the host platform as an execution requirement instead. For example, if you are building on a Mac, you could add the following to your workspace:
register_toolchains("//node_toolchain")
And the following in node_toolchain/BUILD.bazel:
toolchain(
name = "node_toolchain",
exec_compatible_with = [
"@platforms//os:osx",
"@platforms//cpu:x86_64",
],
toolchain = "@nodejs_darwin_amd64_config//:toolchain",
toolchain_type = "@build_bazel_rules_nodejs//toolchains/node:toolchain_type",
)