tools/build_defs/repo/maven_rules.bzl - bazel - Git at Google

 # Copyright 2016 The Bazel Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #    http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.

 # Implementations of Maven rules in Skylark:
 # 1) maven_jar(name, artifact, repository, sha1, settings)
 #    The API of this is largely the same as the native maven_jar rule,
 #    except for the server attribute, which is not implemented. The optional
 #    settings supports passing a custom Maven settings.xml to download the JAR.
 # 2) maven_aar(name, artifact, sha1, settings)
 #    The API of this rule is the same as maven_jar except that the artifact must
 #    be the Maven coordinate of an AAR and it does not support the historical
 #    repository and server attributes.
 # 3) maven_dependency_plugin()
 #    This rule downloads the maven-dependency-plugin used internally
 #    for testing and the implementation for the fetching of artifacts.
 #
 # Maven coordinates are expected to be in this form:
 # groupId:artifactId:version[:packaging][:classifier]
 #
 # Installation requirements prior to using this rule:
 # 1) Maven binary: `mvn`
 # 2) Maven plugin: `maven-dependency-plugin:2.10`
 # Get it: $ mvn org.apache.maven.plugins:maven-dependency-plugin:2.10:get \
 #    -Dartifact=org.apache.maven.plugins:maven-dependency-plugin:2.10 \
 #    -Dmaven.repo.local=$HOME/.m2/repository # or specify your own local repository

 """Rules for retrieving Maven dependencies (experimental)"""

 MAVEN_CENTRAL_URL = "https://repo1.maven.org/maven2"

 # Binary dependencies needed for running the bash commands
 DEPS = ["mvn", "openssl", "awk"]

 MVN_PLUGIN = "org.apache.maven.plugins:maven-dependency-plugin:2.10"

 def _execute(ctx, command):
     return ctx.execute(["bash", "-c", """
 set -ex
 %s""" % command])

 # Fail fast
 def _check_dependencies(ctx):
     for dep in DEPS:
         if ctx.which(dep) == None:
             fail("%s requires %s as a dependency. Please check your PATH." % (ctx.name, dep))

 def _validate_attr(ctx):
     if hasattr(ctx.attr, "server") and (ctx.attr.server != None):
         fail("%s specifies a 'server' attribute which is currently not supported." % ctx.name)

 def _artifact_dir(coordinates):
     return "/".join(coordinates.group_id.split(".") +
                     [coordinates.artifact_id, coordinates.version])

 # Creates a struct containing the different parts of an artifact's FQN.
 # If the fully_qualified_name does not specify a packaging and the rule does
 # not set a default packaging then JAR is assumed.
 def _create_coordinates(fully_qualified_name, packaging = "jar"):
     parts = fully_qualified_name.split(":")
     classifier = None

     if len(parts) == 3:
         group_id, artifact_id, version = parts

         # Updates the FQN with the default packaging so that the Maven plugin
         # downloads the correct artifact.
         fully_qualified_name = "%s:%s" % (fully_qualified_name, packaging)
     elif len(parts) == 4:
         group_id, artifact_id, version, packaging = parts
     elif len(parts) == 5:
         group_id, artifact_id, version, packaging, classifier = parts
     else:
         fail("Invalid fully qualified name for artifact: %s" % fully_qualified_name)

     return struct(
         fully_qualified_name = fully_qualified_name,
         group_id = group_id,
         artifact_id = artifact_id,
         packaging = packaging,
         classifier = classifier,
         version = version,
     )

 # NOTE: Please use this method to define ALL paths that the maven_*
 # rules use. Doing otherwise will lead to inconsistencies and/or errors.
 #
 # CONVENTION: *_path refers to files, *_dir refers to directories.
 def _create_paths(ctx, coordinates):
     """Creates a struct that contains the paths to create the cache WORKSPACE"""

     # e.g. guava-18.0.jar
     artifact_filename = "%s-%s" % (
         coordinates.artifact_id,
         coordinates.version,
     )
     if coordinates.classifier:
         artifact_filename += "-" + coordinates.classifier
     artifact_filename += "." + coordinates.packaging
     sha1_filename = "%s.sha1" % artifact_filename

     # e.g. com/google/guava/guava/18.0
     relative_artifact_dir = _artifact_dir(coordinates)

     # The symlink to the actual artifact is stored in this dir, along with the
     # BUILD file. The dir has the same name as the packaging to support syntax
     # like @guava//jar and @google_play_services//aar.
     symlink_dir = coordinates.packaging

     m2 = ".m2"
     m2_repo = "/".join([m2, "repository"])  # .m2/repository

     return struct(
         artifact_filename = artifact_filename,
         sha1_filename = sha1_filename,
         symlink_dir = ctx.path(symlink_dir),

         # e.g. external/com_google_guava_guava/ \
         #        .m2/repository/com/google/guava/guava/18.0/guava-18.0.jar
         artifact_path = ctx.path("/".join([m2_repo, relative_artifact_dir, artifact_filename])),
         artifact_dir = ctx.path("/".join([m2_repo, relative_artifact_dir])),
         sha1_path = ctx.path("/".join([m2_repo, relative_artifact_dir, sha1_filename])),

         # e.g. external/com_google_guava_guava/jar/guava-18.0.jar
         symlink_artifact_path = ctx.path("/".join([symlink_dir, artifact_filename])),
     )

 _maven_jar_build_file_template = """
 # DO NOT EDIT: automatically generated BUILD file for maven_jar rule {rule_name}

 java_import(
     name = 'jar',
     jars = ['{artifact_filename}'],
     deps = [
 {deps_string}
     ],
     visibility = ['//visibility:public']
 )

 filegroup(
     name = 'file',
     srcs = ['{artifact_filename}'],
     visibility = ['//visibility:public']
 )\n"""

 _maven_aar_build_file_template = """
 # DO NOT EDIT: automatically generated BUILD file for maven_aar rule {rule_name}

 aar_import(
     name = 'aar',
     aar = '{artifact_filename}',
     deps = [
 {deps_string}
     ],
     visibility = ['//visibility:public'],
 )

 filegroup(
     name = 'file',
     srcs = ['{artifact_filename}'],
     visibility = ['//visibility:public']
 )\n"""

 # Provides the syntax "@jar_name//jar" for dependencies
 def _generate_build_file(ctx, template, paths):
     deps_string = "\n".join(["'%s'," % dep for dep in ctx.attr.deps])
     contents = template.format(
         rule_name = ctx.name,
         artifact_filename = paths.artifact_filename,
         deps_string = deps_string,
     )
     ctx.file("%s/BUILD" % paths.symlink_dir, contents, False)

 def _file_exists(ctx, filename):
     return _execute(ctx, "[[ -f %s ]] && exit 0 || exit 1" % filename).return_code == 0

 # Constructs the maven command to retrieve the dependencies from remote
 # repositories using the dependency plugin, and executes it.
 def _mvn_download(ctx, paths, fully_qualified_name):
     # If a custom settings file exists, we'll use that. If not, Maven will use the default settings.
     mvn_flags = ""
     if hasattr(ctx.attr, "settings") and ctx.attr.settings != None:
         ctx.symlink(ctx.attr.settings, "settings.xml")
         mvn_flags += "-s %s " % "settings.xml"

     # dependency:get step. Downloads the artifact into the local repository.
     mvn_get = MVN_PLUGIN + ":get"
     mvn_artifact = "-Dartifact=%s" % fully_qualified_name
     mvn_transitive = "-Dtransitive=false"
     if hasattr(ctx.attr, "repository") and ctx.attr.repository != "":
         mvn_flags += "-Dmaven.repo.remote=%s " % ctx.attr.repository
     command = " ".join(["mvn", mvn_flags, mvn_get, mvn_transitive, mvn_artifact])
     exec_result = _execute(ctx, command)
     if exec_result.return_code != 0:
         fail("%s\n%s\nFailed to fetch Maven dependency" % (exec_result.stdout, exec_result.stderr))

     # dependency:copy step. Moves the artifact from the local repository into //external.
     mvn_copy = MVN_PLUGIN + ":copy"
     mvn_output_dir = "-DoutputDirectory=%s" % paths.artifact_dir
     command = " ".join(["mvn", mvn_flags, mvn_copy, mvn_artifact, mvn_output_dir])
     exec_result = _execute(ctx, command)
     if exec_result.return_code != 0:
         fail("%s\n%s\nFailed to fetch Maven dependency" % (exec_result.stdout, exec_result.stderr))

 def _check_sha1(ctx, paths, sha1):
     actual_sha1 = _execute(ctx, "openssl sha1 %s | awk '{printf $2}'" % paths.artifact_path).stdout

     if sha1.lower() != actual_sha1.lower():
         fail(("{rule_name} has SHA-1 of {actual_sha1}, " +
               "does not match expected SHA-1 ({expected_sha1})").format(
             rule_name = ctx.name,
             expected_sha1 = sha1,
             actual_sha1 = actual_sha1,
         ))
     else:
         _execute(ctx, "echo %s %s > %s" % (sha1, paths.artifact_path, paths.sha1_path))

 def _maven_artifact_impl(ctx, default_rule_packaging, build_file_template):
     # Ensure that we have all of the dependencies installed
     _check_dependencies(ctx)

     # Provide warnings and errors about attributes
     _validate_attr(ctx)

     # Create a struct to contain the different parts of the artifact FQN
     coordinates = _create_coordinates(ctx.attr.artifact, default_rule_packaging)

     # Create a struct to store the relative and absolute paths needed for this rule
     paths = _create_paths(ctx, coordinates)

     _generate_build_file(
         ctx = ctx,
         template = build_file_template,
         paths = paths,
     )

     if _execute(ctx, "mkdir -p %s" % paths.symlink_dir).return_code != 0:
         fail("%s: Failed to create dirs in execution root.\n" % ctx.name)

     # Download the artifact
     _mvn_download(
         ctx = ctx,
         paths = paths,
         fully_qualified_name = coordinates.fully_qualified_name,
     )

     if (ctx.attr.sha1 != ""):
         _check_sha1(
             ctx = ctx,
             paths = paths,
             sha1 = ctx.attr.sha1,
         )

     ctx.symlink(paths.artifact_path, paths.symlink_artifact_path)

 _common_maven_rule_attrs = {
     "artifact": attr.string(
         default = "",
         mandatory = True,
     ),
     "sha1": attr.string(default = ""),
     "settings": attr.label(default = None),
     # Allow the user to specify deps for the generated java_import or aar_import
     # since maven_jar and maven_aar do not automatically pull in transitive
     # dependencies.
     "deps": attr.label_list(),
 }

 def _maven_jar_impl(ctx):
     _maven_artifact_impl(ctx, "jar", _maven_jar_build_file_template)

 def _maven_aar_impl(ctx):
     _maven_artifact_impl(ctx, "aar", _maven_aar_build_file_template)

 maven_jar = repository_rule(
     implementation = _maven_jar_impl,
     attrs = dict(_common_maven_rule_attrs.items() + {
         # Needed for compatability reasons with the native maven_jar rule.
         "repository": attr.string(default = ""),
         "server": attr.label(default = None),
     }.items()),
     local = False,
 )

 maven_aar = repository_rule(
     implementation = _maven_aar_impl,
     attrs = _common_maven_rule_attrs,
     local = False,
 )

 def _maven_dependency_plugin_impl(ctx):
     _BUILD_FILE = """
 # DO NOT EDIT: automatically generated BUILD file for maven_dependency_plugin

 filegroup(
     name = 'files',
     srcs = glob(['**']),
     visibility = ['//visibility:public']
 )
 """
     ctx.file("BUILD", _BUILD_FILE, False)

     _SETTINGS_XML = """
 <!-- # DO NOT EDIT: automatically generated settings.xml for maven_dependency_plugin -->
 <settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
     https://maven.apache.org/xsd/settings-1.0.0.xsd">
   <localRepository>{localRepository}</localRepository>
   <mirrors>
     <mirror>
       <id>central</id>
       <url>{mirror}</url>
       <mirrorOf>*,default</mirrorOf>
     </mirror>
   </mirrors>
 </settings>
 """.format(
         localRepository = ctx.path("repository"),
         mirror = MAVEN_CENTRAL_URL,
     )
     settings_path = ctx.path("settings.xml")
     ctx.file("%s" % settings_path, _SETTINGS_XML, False)

     # Download the plugin with transitive dependencies
     mvn_flags = "-s %s" % settings_path
     mvn_get = MVN_PLUGIN + ":get"
     mvn_artifact = "-Dartifact=%s" % MVN_PLUGIN
     command = " ".join(["mvn", mvn_flags, mvn_get, mvn_artifact])

     exec_result = _execute(ctx, command)
     if exec_result.return_code != 0:
         fail("%s\nFailed to fetch Maven dependency" % exec_result.stderr)

 _maven_dependency_plugin = repository_rule(
     implementation = _maven_dependency_plugin_impl,
 )

 def maven_dependency_plugin():
     _maven_dependency_plugin(name = "m2")
	# Copyright 2016 The Bazel Authors. All rights reserved.
	#
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.

	# Implementations of Maven rules in Skylark:
	# 1) maven_jar(name, artifact, repository, sha1, settings)
	# The API of this is largely the same as the native maven_jar rule,
	# except for the server attribute, which is not implemented. The optional
	# settings supports passing a custom Maven settings.xml to download the JAR.
	# 2) maven_aar(name, artifact, sha1, settings)
	# The API of this rule is the same as maven_jar except that the artifact must
	# be the Maven coordinate of an AAR and it does not support the historical
	# repository and server attributes.
	# 3) maven_dependency_plugin()
	# This rule downloads the maven-dependency-plugin used internally
	# for testing and the implementation for the fetching of artifacts.
	#
	# Maven coordinates are expected to be in this form:
	# groupId:artifactId:version[:packaging][:classifier]
	#
	# Installation requirements prior to using this rule:
	# 1) Maven binary: `mvn`
	# 2) Maven plugin: `maven-dependency-plugin:2.10`
	# Get it: $ mvn org.apache.maven.plugins:maven-dependency-plugin:2.10:get \
	# -Dartifact=org.apache.maven.plugins:maven-dependency-plugin:2.10 \
	# -Dmaven.repo.local=$HOME/.m2/repository # or specify your own local repository

	"""Rules for retrieving Maven dependencies (experimental)"""

	MAVEN_CENTRAL_URL = "https://repo1.maven.org/maven2"

	# Binary dependencies needed for running the bash commands
	DEPS = ["mvn", "openssl", "awk"]

	MVN_PLUGIN = "org.apache.maven.plugins:maven-dependency-plugin:2.10"

	def _execute(ctx, command):
	return ctx.execute(["bash", "-c", """
	set -ex
	%s""" % command])

	# Fail fast
	def _check_dependencies(ctx):
	for dep in DEPS:
	if ctx.which(dep) == None:
	fail("%s requires %s as a dependency. Please check your PATH." % (ctx.name, dep))

	def _validate_attr(ctx):
	if hasattr(ctx.attr, "server") and (ctx.attr.server != None):
	fail("%s specifies a 'server' attribute which is currently not supported." % ctx.name)

	def _artifact_dir(coordinates):
	return "/".join(coordinates.group_id.split(".") +
	[coordinates.artifact_id, coordinates.version])

	# Creates a struct containing the different parts of an artifact's FQN.
	# If the fully_qualified_name does not specify a packaging and the rule does
	# not set a default packaging then JAR is assumed.
	def _create_coordinates(fully_qualified_name, packaging = "jar"):
	parts = fully_qualified_name.split(":")
	classifier = None

	if len(parts) == 3:
	group_id, artifact_id, version = parts

	# Updates the FQN with the default packaging so that the Maven plugin
	# downloads the correct artifact.
	fully_qualified_name = "%s:%s" % (fully_qualified_name, packaging)
	elif len(parts) == 4:
	group_id, artifact_id, version, packaging = parts
	elif len(parts) == 5:
	group_id, artifact_id, version, packaging, classifier = parts
	else:
	fail("Invalid fully qualified name for artifact: %s" % fully_qualified_name)

	return struct(
	fully_qualified_name = fully_qualified_name,
	group_id = group_id,
	artifact_id = artifact_id,
	packaging = packaging,
	classifier = classifier,
	version = version,
	)

	# NOTE: Please use this method to define ALL paths that the maven_*
	# rules use. Doing otherwise will lead to inconsistencies and/or errors.
	#
	# CONVENTION: _path refers to files, _dir refers to directories.
	def _create_paths(ctx, coordinates):
	"""Creates a struct that contains the paths to create the cache WORKSPACE"""

	# e.g. guava-18.0.jar
	artifact_filename = "%s-%s" % (
	coordinates.artifact_id,
	coordinates.version,
	)
	if coordinates.classifier:
	artifact_filename += "-" + coordinates.classifier
	artifact_filename += "." + coordinates.packaging
	sha1_filename = "%s.sha1" % artifact_filename

	# e.g. com/google/guava/guava/18.0
	relative_artifact_dir = _artifact_dir(coordinates)

	# The symlink to the actual artifact is stored in this dir, along with the
	# BUILD file. The dir has the same name as the packaging to support syntax
	# like @guava//jar and @google_play_services//aar.
	symlink_dir = coordinates.packaging

	m2 = ".m2"
	m2_repo = "/".join([m2, "repository"]) # .m2/repository

	return struct(
	artifact_filename = artifact_filename,
	sha1_filename = sha1_filename,
	symlink_dir = ctx.path(symlink_dir),

	# e.g. external/com_google_guava_guava/ \
	# .m2/repository/com/google/guava/guava/18.0/guava-18.0.jar
	artifact_path = ctx.path("/".join([m2_repo, relative_artifact_dir, artifact_filename])),
	artifact_dir = ctx.path("/".join([m2_repo, relative_artifact_dir])),
	sha1_path = ctx.path("/".join([m2_repo, relative_artifact_dir, sha1_filename])),

	# e.g. external/com_google_guava_guava/jar/guava-18.0.jar
	symlink_artifact_path = ctx.path("/".join([symlink_dir, artifact_filename])),
	)

	_maven_jar_build_file_template = """
	# DO NOT EDIT: automatically generated BUILD file for maven_jar rule {rule_name}

	java_import(
	name = 'jar',
	jars = ['{artifact_filename}'],
	deps = [
	{deps_string}
	],
	visibility = ['//visibility:public']
	)

	filegroup(
	name = 'file',
	srcs = ['{artifact_filename}'],
	visibility = ['//visibility:public']
	)\n"""

	_maven_aar_build_file_template = """
	# DO NOT EDIT: automatically generated BUILD file for maven_aar rule {rule_name}

	aar_import(
	name = 'aar',
	aar = '{artifact_filename}',
	deps = [
	{deps_string}
	],
	visibility = ['//visibility:public'],
	)

	filegroup(
	name = 'file',
	srcs = ['{artifact_filename}'],
	visibility = ['//visibility:public']
	)\n"""

	# Provides the syntax "@jar_name//jar" for dependencies
	def _generate_build_file(ctx, template, paths):
	deps_string = "\n".join(["'%s'," % dep for dep in ctx.attr.deps])
	contents = template.format(
	rule_name = ctx.name,
	artifact_filename = paths.artifact_filename,
	deps_string = deps_string,
	)
	ctx.file("%s/BUILD" % paths.symlink_dir, contents, False)

	def _file_exists(ctx, filename):
	return _execute(ctx, "[[ -f %s ]] && exit 0 \|\| exit 1" % filename).return_code == 0

	# Constructs the maven command to retrieve the dependencies from remote
	# repositories using the dependency plugin, and executes it.
	def _mvn_download(ctx, paths, fully_qualified_name):
	# If a custom settings file exists, we'll use that. If not, Maven will use the default settings.
	mvn_flags = ""
	if hasattr(ctx.attr, "settings") and ctx.attr.settings != None:
	ctx.symlink(ctx.attr.settings, "settings.xml")
	mvn_flags += "-s %s " % "settings.xml"

	# dependency:get step. Downloads the artifact into the local repository.
	mvn_get = MVN_PLUGIN + ":get"
	mvn_artifact = "-Dartifact=%s" % fully_qualified_name
	mvn_transitive = "-Dtransitive=false"
	if hasattr(ctx.attr, "repository") and ctx.attr.repository != "":
	mvn_flags += "-Dmaven.repo.remote=%s " % ctx.attr.repository
	command = " ".join(["mvn", mvn_flags, mvn_get, mvn_transitive, mvn_artifact])
	exec_result = _execute(ctx, command)
	if exec_result.return_code != 0:
	fail("%s\n%s\nFailed to fetch Maven dependency" % (exec_result.stdout, exec_result.stderr))

	# dependency:copy step. Moves the artifact from the local repository into //external.
	mvn_copy = MVN_PLUGIN + ":copy"
	mvn_output_dir = "-DoutputDirectory=%s" % paths.artifact_dir
	command = " ".join(["mvn", mvn_flags, mvn_copy, mvn_artifact, mvn_output_dir])
	exec_result = _execute(ctx, command)
	if exec_result.return_code != 0:
	fail("%s\n%s\nFailed to fetch Maven dependency" % (exec_result.stdout, exec_result.stderr))

	def _check_sha1(ctx, paths, sha1):
	actual_sha1 = _execute(ctx, "openssl sha1 %s \| awk '{printf $2}'" % paths.artifact_path).stdout

	if sha1.lower() != actual_sha1.lower():
	fail(("{rule_name} has SHA-1 of {actual_sha1}, " +
	"does not match expected SHA-1 ({expected_sha1})").format(
	rule_name = ctx.name,
	expected_sha1 = sha1,
	actual_sha1 = actual_sha1,
	))
	else:
	_execute(ctx, "echo %s %s > %s" % (sha1, paths.artifact_path, paths.sha1_path))

	def _maven_artifact_impl(ctx, default_rule_packaging, build_file_template):
	# Ensure that we have all of the dependencies installed
	_check_dependencies(ctx)

	# Provide warnings and errors about attributes
	_validate_attr(ctx)

	# Create a struct to contain the different parts of the artifact FQN
	coordinates = _create_coordinates(ctx.attr.artifact, default_rule_packaging)

	# Create a struct to store the relative and absolute paths needed for this rule
	paths = _create_paths(ctx, coordinates)

	_generate_build_file(
	ctx = ctx,
	template = build_file_template,
	paths = paths,
	)

	if _execute(ctx, "mkdir -p %s" % paths.symlink_dir).return_code != 0:
	fail("%s: Failed to create dirs in execution root.\n" % ctx.name)

	# Download the artifact
	_mvn_download(
	ctx = ctx,
	paths = paths,
	fully_qualified_name = coordinates.fully_qualified_name,
	)

	if (ctx.attr.sha1 != ""):
	_check_sha1(
	ctx = ctx,
	paths = paths,
	sha1 = ctx.attr.sha1,
	)

	ctx.symlink(paths.artifact_path, paths.symlink_artifact_path)

	_common_maven_rule_attrs = {
	"artifact": attr.string(
	default = "",
	mandatory = True,
	),
	"sha1": attr.string(default = ""),
	"settings": attr.label(default = None),
	# Allow the user to specify deps for the generated java_import or aar_import
	# since maven_jar and maven_aar do not automatically pull in transitive
	# dependencies.
	"deps": attr.label_list(),
	}

	def _maven_jar_impl(ctx):
	_maven_artifact_impl(ctx, "jar", _maven_jar_build_file_template)

	def _maven_aar_impl(ctx):
	_maven_artifact_impl(ctx, "aar", _maven_aar_build_file_template)

	maven_jar = repository_rule(
	implementation = _maven_jar_impl,
	attrs = dict(_common_maven_rule_attrs.items() + {
	# Needed for compatability reasons with the native maven_jar rule.
	"repository": attr.string(default = ""),
	"server": attr.label(default = None),
	}.items()),
	local = False,
	)

	maven_aar = repository_rule(
	implementation = _maven_aar_impl,
	attrs = _common_maven_rule_attrs,
	local = False,
	)

	def _maven_dependency_plugin_impl(ctx):
	_BUILD_FILE = """
	# DO NOT EDIT: automatically generated BUILD file for maven_dependency_plugin

	filegroup(
	name = 'files',
	srcs = glob(['**']),
	visibility = ['//visibility:public']
	)
	"""
	ctx.file("BUILD", _BUILD_FILE, False)

	_SETTINGS_XML = """
	<!-- # DO NOT EDIT: automatically generated settings.xml for maven_dependency_plugin -->
	<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
	https://maven.apache.org/xsd/settings-1.0.0.xsd">
	<localRepository>{localRepository}</localRepository>
	<mirrors>
	<mirror>
	<id>central</id>
	<url>{mirror}</url>
	<mirrorOf>*,default</mirrorOf>
	</mirror>
	</mirrors>
	</settings>
	""".format(
	localRepository = ctx.path("repository"),
	mirror = MAVEN_CENTRAL_URL,
	)
	settings_path = ctx.path("settings.xml")
	ctx.file("%s" % settings_path, _SETTINGS_XML, False)

	# Download the plugin with transitive dependencies
	mvn_flags = "-s %s" % settings_path
	mvn_get = MVN_PLUGIN + ":get"
	mvn_artifact = "-Dartifact=%s" % MVN_PLUGIN
	command = " ".join(["mvn", mvn_flags, mvn_get, mvn_artifact])

	exec_result = _execute(ctx, command)
	if exec_result.return_code != 0:
	fail("%s\nFailed to fetch Maven dependency" % exec_result.stderr)

	_maven_dependency_plugin = repository_rule(
	implementation = _maven_dependency_plugin_impl,
	)

	def maven_dependency_plugin():
	_maven_dependency_plugin(name = "m2")