Node.js toolchain support

BUILD.bazel

@@ -19,6 +19,7 @@ bzl_library(
         "//internal/jasmine_node_test:bzl",
         "//internal/npm_package:bzl",
         "//internal/rollup:bzl",
+        "//toolchains/node:bzl",
     ],
 )
 
@@ -68,6 +69,7 @@ npm_package(
         "//internal/npm_install:package_contents",
         "//internal/npm_package:package_contents",
         "//internal/web_package:package_contents",
+        "//toolchains/node:package_contents",
     ],
 )
 

README.md

@@ -459,6 +459,24 @@ Note: the arguments passed to `bazel run` after `--` are forwarded to the execut
 
 [bazel instructions]: https://docs.bazel.build/versions/master/install.html
 
+### Toolchains
+
+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](https://docs.bazel.build/versions/master/toolchains.html).
+
+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.
+
+#### Cross-compilation
+
+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:darwin_amd64`
+- `@build_bazel_rules_nodejs//toolchains/node:windows_amd64`
+
+So 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.
+
 ## Usage
 
 ### Running a program from npm

internal/common/os_name.bzl

@@ -15,21 +15,38 @@
 """Helper function for repository rules
 """
 
-def os_name(repository_ctx):
+OS_ARCH_NAMES = [
+    ("darwin", "amd64"),
+    ("windows", "amd64"),
+    ("linux", "amd64"),
+]
+
+OS_NAMES = ["_".join(os_arch_name) for os_arch_name in OS_ARCH_NAMES]
+
+def os_name(rctx):
     """Get the os name for a repository rule
 
     Args:
-      repository_ctx: The repository rule context
+      rctx: The repository rule context
 
     Returns:
       A string describing the os for a repository rule
     """
-    os_name = repository_ctx.os.name.lower()
+    os_name = rctx.os.name.lower()
     if os_name.startswith("mac os"):
-        return "darwin_amd64"
+        return OS_NAMES[0]
     elif os_name.find("windows") != -1:
-        return "windows_amd64"
+        return OS_NAMES[1]
     elif os_name.startswith("linux"):
-        return "linux_amd64"
+        return OS_NAMES[2]
     else:
         fail("Unsupported operating system: " + os_name)
+
+def is_darwin_os(rctx):
+    return os_name(rctx) == OS_NAMES[0]
+
+def is_windows_os(rctx):
+    return os_name(rctx) == OS_NAMES[1]
+
+def is_linux_os(rctx):
+    return os_name(rctx) == OS_NAMES[2]

internal/copy_repository/copy_repository.bzl

@@ -15,15 +15,14 @@
 """Custom copy_repository rule used by npm_install and yarn_install.
 """
 
-load("@build_bazel_rules_nodejs//internal/common:os_name.bzl", "os_name")
+load("@build_bazel_rules_nodejs//internal/common:os_name.bzl", "is_windows_os")
 
 def _copy_file(rctx, src):
     rctx.template(src.basename, src)
 
 def _copy_repository_impl(rctx):
     src_path = "/".join(str(rctx.path(rctx.attr.marker_file)).split("/")[:-1])
-    is_windows = os_name(rctx).find("windows") != -1
-    if is_windows:
+    if is_windows_os(rctx):
         _copy_file(rctx, rctx.path(Label("@build_bazel_rules_nodejs//internal/copy_repository:_copy.bat")))
         result = rctx.execute(["cmd.exe", "/C", "_copy.bat", src_path.replace("/", "\\"), "."])
     else:

internal/node/BUILD.bazel

@@ -31,6 +31,7 @@ exports_files([
     "node_repositories.bzl",  # Exported to be consumed for generating skydoc.
     "node_launcher.sh",
     "node_loader.js",
+    "BUILD.nodejs_host_os_alias.tpl",
 ])
 
 filegroup(
@@ -39,6 +40,9 @@ filegroup(
         "*.bzl",
         "*.js",
         "*.sh",
-    ]) + ["BUILD.bazel"],
+    ]) + [
+        "BUILD.bazel",
+        "BUILD.nodejs_host_os_alias.tpl",
+    ],
     visibility = ["//:__pkg__"],
 )

internal/node/BUILD.nodejs_host_os_alias.tpl

@@ -0,0 +1,27 @@
+# Generated by node_repositories.bzl
+package(default_visibility = ["//visibility:public"])
+
+# aliases for exports_files
+alias(name = "run_npm.sh.template", actual = "TEMPLATE_run_npm")
+alias(name = "bin/node_repo_args.sh", actual = "TEMPLATE_node_repo_args")
+# windows specific aliases
+alias(name = "bin/nodejs/node.exe", actual = "TEMPLATE_actual_node_bin")
+alias(name = "bin/node.cmd", actual = "TEMPLATE_wrapped_node_bin")
+alias(name = "bin/npm.cmd", actual = "TEMPLATE_npm")
+alias(name = "bin/npm_node_repositories.cmd", actual = "TEMPLATE__npm_node_repositories")
+alias(name = "bin/yarn.cmd", actual = "TEMPLATE_yarn")
+alias(name = "bin/yarn_node_repositories.cmd", actual = "TEMPLATE__yarn_node_repositories")
+# linux/mac specific aliases
+alias(name = "bin/nodejs/bin/node", actual = "TEMPLATE_actual_node_bin")
+alias(name = "bin/node", actual = "TEMPLATE_wrapped_node_bin")
+alias(name = "bin/npm", actual = "TEMPLATE_npm")
+alias(name = "bin/npm_node_repositories", actual = "TEMPLATE__npm_node_repositories")
+alias(name = "bin/yarn", actual = "TEMPLATE_yarn")
+alias(name = "bin/yarn_node_repositories", actual = "TEMPLATE__yarn_node_repositories")
+
+
+# aliases for other aliases
+alias(name = "node_bin", actual = "TEMPLATE_actual_node_bin")
+alias(name = "node", actual = "TEMPLATE_wrapped_node_bin")
+alias(name = "npm", actual = "TEMPLATE__npm_node_repositories")
+alias(name = "yarn", actual = "TEMPLATE__yarn_node_repositories")

internal/node/node.bzl

@@ -14,7 +14,7 @@
 
 """Executing programs
 
-These rules run the node binary with the given sources.
+These rules run the node executable with the given sources.
 
 They support module mapping: any targets in the transitive dependencies with
 a `module_name` attribute can be `require`d by that name.
@@ -125,7 +125,6 @@ def _short_path_to_manifest_path(ctx, short_path):
         return ctx.workspace_name + "/" + short_path
 
 def _nodejs_binary_impl(ctx):
-    node = ctx.file.node
     node_modules = depset(ctx.files.node_modules)
 
     # Also include files from npm fine grained deps as inputs.
@@ -164,25 +163,38 @@ def _nodejs_binary_impl(ctx):
     if hasattr(ctx.attr, "expected_exit_code"):
         expected_exit_code = ctx.attr.expected_exit_code
 
-    substitutions = {
-        "TEMPLATED_args": " ".join([
-            expand_location_into_runfiles(ctx, a)
-            for a in ctx.attr.templated_args
-        ]),
-        "TEMPLATED_env_vars": env_vars,
-        "TEMPLATED_expected_exit_code": str(expected_exit_code),
-        "TEMPLATED_node": _short_path_to_manifest_path(ctx, node.short_path),
-        "TEMPLATED_repository_args": _short_path_to_manifest_path(ctx, ctx.file._repository_args.short_path),
-        "TEMPLATED_script_path": script_path,
-    }
-    ctx.actions.expand_template(
-        template = ctx.file._launcher_template,
-        output = ctx.outputs.script,
-        substitutions = substitutions,
-        is_executable = True,
-    )
+    node_tool_info = ctx.toolchains["@build_bazel_rules_nodejs//toolchains/node:toolchain_type"].nodeinfo
+    node_tool_files = []
+    if node_tool_info.target_tool_path == "" and not node_tool_info.target_tool:
+        # If tool_path is empty and tool_target is None then there is no local
+        # node tool, we will just print a nice error message if the user
+        # attempts to do bazel run
+        fail("The node toolchain was not properly configured so %s cannot be executed. Make sure that target_tool_path or target_tool is set." % ctx.attr.name)
+    else:
+        node_tool = node_tool_info.target_tool_path
+        if node_tool_info.target_tool:
+            node_tool_files += node_tool_info.target_tool.files.to_list()
+            node_tool = _short_path_to_manifest_path(ctx, node_tool_files[0].short_path)
 
-    runfiles = depset([node, ctx.outputs.loader, ctx.file._repository_args], transitive = [sources, node_modules])
+        substitutions = {
+            "TEMPLATED_args": " ".join([
+                expand_location_into_runfiles(ctx, a)
+                for a in ctx.attr.templated_args
+            ]),
+            "TEMPLATED_env_vars": env_vars,
+            "TEMPLATED_expected_exit_code": str(expected_exit_code),
+            "TEMPLATED_node": node_tool,
+            "TEMPLATED_repository_args": _short_path_to_manifest_path(ctx, ctx.file._repository_args.short_path),
+            "TEMPLATED_script_path": script_path,
+        }
+        ctx.actions.expand_template(
+            template = ctx.file._launcher_template,
+            output = ctx.outputs.script,
+            substitutions = substitutions,
+            is_executable = True,
+        )
+
+    runfiles = depset(node_tool_files + [ctx.outputs.loader, ctx.file._repository_args], transitive = [sources, node_modules])
 
     # entry point is only needed in runfiles if it is a .js file
     if ctx.file.entry_point.extension == "js":
@@ -192,8 +204,7 @@ def _nodejs_binary_impl(ctx):
         executable = ctx.outputs.script,
         runfiles = ctx.runfiles(
             transitive_files = runfiles,
-            files = [
-                        node,
+            files = node_tool_files + [
                         ctx.outputs.loader,
                     ] + ctx.files._source_map_support_files +
 
@@ -292,11 +303,6 @@ _NODEJS_EXECUTABLE_ATTRS = {
         in TypeScript.""",
         default = True,
     ),
-    "node": attr.label(
-        doc = """The node entry point target.""",
-        default = Label("@nodejs//:node_bin"),
-        allow_single_file = True,
-    ),
     "node_modules": attr.label(
         doc = """The npm packages which should be available to `require()` during
         execution.
@@ -406,6 +412,7 @@ nodejs_binary = rule(
     attrs = _NODEJS_EXECUTABLE_ATTRS,
     executable = True,
     outputs = _NODEJS_EXECUTABLE_OUTPUTS,
+    toolchains = ["@build_bazel_rules_nodejs//toolchains/node:toolchain_type"],
 )
 """Runs some JavaScript code in NodeJS.
 """
@@ -420,6 +427,7 @@ nodejs_test = rule(
     }),
     test = True,
     outputs = _NODEJS_EXECUTABLE_OUTPUTS,
+    toolchains = ["@build_bazel_rules_nodejs//toolchains/node:toolchain_type"],
 )
 """
 Identical to `nodejs_binary`, except this can be used with `bazel test` as well.