Transitive Maven artifact resolution and publishing rules for Bazel.
- Main build:
- Examples build:
- Features
- Examples
- Prerequisites
- Usage
- API Reference
- Pinning artifacts and integration with Bazel's downloader
- (Experimental) Support for Maven BOM files
- Generated targets
- Outdated artifacts
- Advanced usage
- Fetch source JARs
- Checksum verification
- Using a custom Coursier download url
artifacthelper macrojava_plugin_artifacthelper macro- Multiple
maven_installdeclarations for isolated artifact version trees - Detailed dependency information specifications
- Artifact exclusion
- Compile-only dependencies
- Test-only dependencies
- Resolving user-specified and transitive dependency version conflicts
- Overriding generated targets
- Proxies
- Repository aliases
- Repository remapping
- Hiding transitive dependencies
- Accessing transitive dependencies list
- Fetch and resolve timeout
- Ignoring empty jars
- Duplicate artifact warning
- Provide JVM options for Coursier with
COURSIER_OPTS - Resolving issues with nonstandard system default JDKs
- Exporting and consuming artifacts from external repositories
- Publishing to External Repositories
- Configuring the dependency resolver
- IPv6 support
- Developing this project
- MODULE.bazel bzlmod configuration (Bazel 7 and above)
- WORKSPACE configuration
- Artifact version resolution with Coursier or Maven
- Import downloaded JAR, AAR, source JARs
- Export built JARs to Maven repositories
- Pin resolved artifacts with their SHA-256 checksums into a version-controllable JSON file
- Custom Maven repositories
- Private Maven repositories using
netrcfiles - Integration with Bazel's downloader and caching mechanisms for sharing artifacts across Bazel workspaces
- Versionless target labels for simpler dependency management
- Ability to declare multiple sets of versioned artifacts
- Supported on Windows, macOS, Linux
Get the latest release here.
You can find examples in the examples/ directory.
Find other GitHub projects using rules_jvm_external
with this search query.
- Bazel 5.4.1 and above.
Support for Bazel versions between 4.x and 5.4 is only available on rules_jvm_external releases 5.x.
Support for Bazel versions before 4.0.0 is only available on rules_jvm_external releases 4.2 or earlier.
If you are starting a new project, or your project is already using Bazel 7 and
above, we recommend using bzlmod to
manage your external dependencies, including Maven dependencies with
rules_jvm_external. It address several shortcomings of the WORKSPACE
mechanism. If you are unable to use bzlmod, rules_jvm_external also supports
the WORKSPACE mechanism (see below).
See bzlmod.md for the usage instructions. bzlmod is on-by-default in Bazel 7.0.
List the top-level Maven artifacts and servers in the WORKSPACE:
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
RULES_JVM_EXTERNAL_TAG = "4.5"
RULES_JVM_EXTERNAL_SHA = "b17d7388feb9bfa7f2fa09031b32707df529f26c91ab9e5d909eb1676badd9a6"
http_archive(
name = "rules_jvm_external",
strip_prefix = "rules_jvm_external-%s" % RULES_JVM_EXTERNAL_TAG,
sha256 = RULES_JVM_EXTERNAL_SHA,
url = "https://github.com/bazelbuild/rules_jvm_external/archive/%s.zip" % RULES_JVM_EXTERNAL_TAG,
)
load("@rules_jvm_external//:repositories.bzl", "rules_jvm_external_deps")
rules_jvm_external_deps()
load("@rules_jvm_external//:setup.bzl", "rules_jvm_external_setup")
rules_jvm_external_setup()
load("@rules_jvm_external//:defs.bzl", "maven_install")
maven_install(
artifacts = [
"junit:junit:4.12",
"androidx.test.espresso:espresso-core:3.1.1",
"org.hamcrest:hamcrest-library:1.3",
],
repositories = [
# Private repositories are supported through HTTP Basic auth
"http://username:password@localhost:8081/artifactory/my-repository",
"https://maven.google.com",
"https://repo1.maven.org/maven2",
],
)Credentials for private repositories can also be specified using a property file or environment variables. See the Coursier documentation for more information.
rules_jvm_external_deps uses a default list of maven repositories to download
rules_jvm_external's own dependencies from. Should you wish to change this,
use the repositories parameter, and also set the path to the lock file:
rules_jvm_external_deps(
repositories = ["https://mycorp.com/artifacts"],
deps_lock_file = "@//:rules_jvm_external_deps_install.json")
rules_jvm_external_setup()If you are using bzlmod, define an install tag in your root
MODULE.bazel which overrides the values:
maven.install(
name = "rules_jvm_external_deps",
repositories = ["https://mycorp.com/artifacts"],
lock_file = "//:rules_jvm_external_deps_install.json",
)Once these changes have been made, repin using REPIN=1 bazel run @rules_jvm_external_deps//:pin and commit the file to your version
control system (note that at this point you will need to maintain your
customized rules_jvm_external_deps_install.json):
Next, reference the artifacts in the BUILD file with their versionless label:
java_library(
name = "java_test_deps",
exports = [
"@maven//:junit_junit",
"@maven//:org_hamcrest_hamcrest_library",
],
)
android_library(
name = "android_test_deps",
exports = [
"@maven//:junit_junit",
"@maven//:androidx_test_espresso_espresso_core",
],
)The default label syntax for an artifact foo.bar:baz-qux:1.2.3 is @maven//:foo_bar_baz_qux. That is,
- All non-alphanumeric characters are substituted with underscores.
- Only the group and artifact IDs are required.
- The target is located in the
@maventop level package (@maven//).
You can find the complete API reference at docs/api.md.
rules_jvm_external supports pinning artifacts and their SHA-256 checksums into
a maven_install.json file that can be checked into your repository.
Without artifact pinning, in a clean checkout of your project, rules_jvm_external
executes the full artifact resolution and fetching steps (which can take a bit of time)
and does not verify the integrity of the artifacts against their checksums. The
downloaded artifacts also cannot be shared across Bazel workspaces.
By pinning artifact versions, you can get improved artifact resolution and build times,
since using maven_install.json enables rules_jvm_external to integrate with Bazel's
downloader that caches files on their sha256 checksums. It also improves resiliency and
integrity by tracking the sha256 checksums and original artifact urls in the
JSON file.
Since all artifacts are persisted locally in Bazel's cache, it means that
fully offline builds are possible after the initial bazel fetch @maven//....
The artifacts are downloaded with http_file which supports netrc for authentication.
Your ~/.netrc will be included automatically.
To pass machine login credentials in the ~/.netrc file to coursier, specify
use_credentials_from_home_netrc_file = True in your maven_install rule.
For additional credentials, add them in the repository URLs passed to maven_install
(so they will be included in the generated JSON).
Alternatively, pass an array of additional_netrc_lines to maven_install for authentication with credentials from
outside the workspace.
To get started with pinning artifacts, run the following command to generate the
initial maven_install.json at the root of your Bazel workspace:
$ bazel run @maven//:pin
Then, specify maven_install_json in maven_install and load
pinned_maven_install from @maven//:defs.bzl:
maven_install(
# artifacts, repositories, ...
maven_install_json = "//:maven_install.json",
)
load("@maven//:defs.bzl", "pinned_maven_install")
pinned_maven_install()Note: The //:maven_install.json label assumes you have a BUILD file in
your project's root directory. If you do not have one, create an empty BUILD
file to fix issues you may see. See
#242
Note: If you're using an older version of rules_jvm_external and
haven't repinned your dependencies, you may see a warning that you lock
file "does not contain a signature of the required artifacts" then don't
worry: either ignore the warning or repin the dependencies.
Whenever you make a change to the list of artifacts or repositories and want
to update maven_install.json, run this command to re-pin the unpinned @maven
repository:
$ REPIN=1 bazel run @maven//:pin
Without re-pinning, maven_install will not pick up the changes made to the
WORKSPACE, as maven_install.json is now the source of truth.
It can be easy to forget to update the maven_install.json lock file
when updating artifacts in a maven_install. Normally,
rules_jvm_external will print a warning to the console and continue
the build when this happens, but by setting the
fail_if_repin_required attribute to True, this will be treated as
a build error, causing the build to fail. When this attribute is set,
it is possible to update the maven_install.json file using:
# To repin everything:
REPIN=1 bazel run @maven//:pin
# To only repin rules_jvm_external:
RULES_JVM_EXTERNAL_REPIN=1 bazel run @maven//:pinAlternatively, it is also possible to modify the
fail_if_repin_required attribute in your WORKSPACE file, run
bazel run @maven//:pin and then reset the
fail_if_repin_required attribute.
You can specify a custom location for maven_install.json by changing the
maven_install_json attribute value to point to the new file label. For example:
maven_install(
name = "maven_install_in_custom_location",
artifacts = ["com.google.guava:guava:27.0-jre"],
repositories = ["https://repo1.maven.org/maven2"],
maven_install_json = "@rules_jvm_external//tests/custom_maven_install:maven_install.json",
)
load("@maven_install_in_custom_location//:defs.bzl", "pinned_maven_install")
pinned_maven_install()Future artifact pinning updates to maven_install.json will overwrite the file
at the specified path instead of creating a new one at the default root
directory location.
If you have multiple maven_install declarations, you have to alias
pinned_maven_install to another name to prevent redefinitions:
maven_install(
name = "foo",
maven_install_json = "//:foo_maven_install.json",
# ...
)
load("@foo//:defs.bzl", foo_pinned_maven_install = "pinned_maven_install")
foo_pinned_maven_install()
maven_install(
name = "bar",
maven_install_json = "//:bar_maven_install.json",
# ...
)
load("@bar//:defs.bzl", bar_pinned_maven_install = "pinned_maven_install")
bar_pinned_maven_install()Support for Maven BOMs can be enabled by switching the resolver used by maven_install to one that supports Maven BOMs.
This can be done by setting the resolver attribute to maven. The new resolver will likely result in different
resolutions than the existing resolver, so it is advised to re-run your dependencies pin.
The new resolver requires you to use a maven_install_json file, though if you have not yet pinned your dependencies,
this can simply be an empty file.
As an example:
maven.install(
# Resolution using BOMs is supported by using the `maven` resolver
resolver = "maven",
boms = [
"org.seleniumhq.selenium:selenium-bom:4.18.1",
],
artifacts = [
# This dependency is included in the `selenium-bom`, so we can omit the version number
"org.seleniumhq.selenium:selenium-java",
],
# The `maven` resolver requires a lock file, though this can be an empty file before pinning
lock_file = "//:manifest_install.json",
)For the junit:junit example, using bazel query @maven//:all --output=build, we can see that the rule generated these targets:
alias(
name = "junit_junit_4_12",
actual = "@maven//:junit_junit",
)
jvm_import(
name = "junit_junit",
jars = ["@maven//:https/repo1.maven.org/maven2/junit/junit/4.12/junit-4.12.jar"],
srcjar = "@maven//:https/repo1.maven.org/maven2/junit/junit/4.12/junit-4.12-sources.jar",
deps = ["@maven//:org_hamcrest_hamcrest_core"],
tags = ["maven_coordinates=junit:junit:4.12"],
)
jvm_import(
name = "org_hamcrest_hamcrest_core",
jars = ["@maven//:https/repo1.maven.org/maven2/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar"],
srcjar = "@maven//:https/repo1.maven.org/maven2/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3-sources.jar",
deps = [],
tags = ["maven_coordinates=org.hamcrest:hamcrest.library:1.3"],
)These targets can be referenced by:
@maven//:junit_junit@maven//:org_hamcrest_hamcrest_core
Transitive classes: To use a class from hamcrest-core in your test, it's not sufficient to just
depend on @maven//:junit_junit even though JUnit depends on Hamcrest. The compile classes are not exported
transitively, so your test should also depend on @maven//:org_hamcrest_hamcrest_core.
Original coordinates: The generated tags attribute value also contains the original coordinates of
the artifact, which integrates with rules like bazel-common's
pom_file
for generating POM files. See the pom_file_generation
example for more information.
To check for updates of artifacts, run the following command at the root of your Bazel workspace:
$ bazel run @maven//:outdated
To download the source JAR alongside the main artifact JAR, set fetch_sources = True in maven_install:
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
fetch_sources = True,
)Artifact resolution will fail if a SHA-1 or MD5 checksum file for the
artifact is missing in the repository. To disable this behavior, set
fail_on_missing_checksum = False in maven_install:
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
fail_on_missing_checksum = False,
)By default bazel bootstraps Coursier via the urls specificed in versions.bzl. However in case they are not directly accessible in your environment, you can also specify a custom url to download Coursier. For example:
$ bazel build @maven_with_unsafe_shared_cache//... --repo_env=COURSIER_URL='https://my_secret_host.com/vXYZ/coursier.jar'
Please note it still requires the SHA to match.
The artifact macro translates the artifact's group:artifact coordinates to
the label of the versionless target. This target is an
alias that
points to the java_import/aar_import target in the @maven repository,
which includes the transitive dependencies specified in the top level artifact's
POM file.
For example, @maven//:junit_junit is equivalent to artifact("junit:junit").
To use it, add the load statement to the top of your BUILD file:
load("@rules_jvm_external//:defs.bzl", "artifact")Full group:artifact:[packaging:[classifier:]]version maven coordinates are also
supported and translate to corresponding versionless target.
Note that usage of this macro makes BUILD file refactoring with tools like
buildozer more difficult, because the macro hides the actual target label at
the syntax level.
The java_plugin_artifact macro finds a java_plugin target which can be used
to run an annotation procesor from a particular artifact.
For example, if you pull com.google.auto.value:auto-value into a
maven_install, you can use the java_plugin_artifact macro in the plugins
attribute of a target like java_library:
java_library(
name = "some_lib",
srcs = ["SrcUsingAuto.java"],
plugins = [
java_plugin_artifact("com.google.auto.value:auto-value", "com.google.auto.value.processor.AutoValueProcessor"),
],
)If your WORKSPACE contains several projects that use different versions of the
same artifact, you can specify multiple maven_install declarations in the
WORKSPACE, with a unique repository name for each of them.
For example, if you want to use the JRE version of Guava for a server app, and
the Android version for an Android app, you can specify two maven_install
declarations:
maven_install(
name = "server_app",
artifacts = [
"com.google.guava:guava:27.0-jre",
],
repositories = [
"https://repo1.maven.org/maven2",
],
)
maven_install(
name = "android_app",
artifacts = [
"com.google.guava:guava:27.0-android",
],
repositories = [
"https://repo1.maven.org/maven2",
],
)This way, rules_jvm_external will invoke coursier to resolve artifact versions for
both repositories independent of each other. Coursier will fail if it encounters
version conflicts that it cannot resolve. The two Guava targets can then be used
in BUILD files like so:
java_binary(
name = "my_server_app",
srcs = ...
deps = [
# a versionless alias to @server_app//:com_google_guava_guava_27_0_jre
"@server_app//:com_google_guava_guava",
]
)
android_binary(
name = "my_android_app",
srcs = ...
deps = [
# a versionless alias to @android_app//:com_google_guava_guava_27_0_android
"@android_app//:com_google_guava_guava",
]
)Although you can always give a dependency as a Maven coordinate string, occasionally special handling is required in the form of additional directives to properly situate the artifact in the dependency tree. For example, a given artifact may need to have one of its dependencies excluded to prevent a conflict.
This situation is provided for by allowing the artifact to be specified as a map
containing all of the required information. This map can express more
information than the coordinate strings can, so internally the coordinate
strings are parsed into the artifact map with default values for the additional
items. To assist in generating the maps, you can pull in the file specs.bzl
alongside defs.bzl and import the maven struct, which provides several
helper functions to assist in creating these maps. An example:
load("@rules_jvm_external//:defs.bzl", "artifact")
load("@rules_jvm_external//:specs.bzl", "maven")
maven_install(
artifacts = [
maven.artifact(
group = "com.google.guava",
artifact = "guava",
version = "27.0-android",
exclusions = [
...
]
),
"junit:junit:4.12",
...
],
repositories = [
maven.repository(
"https://some.private.maven.re/po",
user = "johndoe",
password = "example-password"
),
"https://repo1.maven.org/maven2",
...
],
)Note when using bzlmod the syntax in MODULE.bazel is
different than shown above.
If you want to exclude an artifact from the transitive closure of a top level
artifact, specify its group-id:artifact-id in the exclusions attribute of
the maven.artifact helper:
load("@rules_jvm_external//:specs.bzl", "maven")
maven_install(
artifacts = [
maven.artifact(
group = "com.google.guava",
artifact = "guava",
version = "27.0-jre",
exclusions = [
maven.exclusion(
group = "org.codehaus.mojo",
artifact = "animal-sniffer-annotations"
),
"com.google.j2objc:j2objc-annotations",
]
),
# ...
],
repositories = [
# ...
],
)You can specify the exclusion using either the maven.exclusion helper or the
group-id:artifact-id string directly.
You can also exclude artifacts globally using the excluded_artifacts
attribute in maven_install:
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
excluded_artifacts = [
"com.google.guava:guava",
],
)If you want to mark certain artifacts as compile-only dependencies, use the
neverlink attribute in the maven.artifact helper:
load("@rules_jvm_external//:specs.bzl", "maven")
maven_install(
artifacts = [
maven.artifact("com.squareup", "javapoet", "1.11.0", neverlink = True),
],
# ...
)This instructs rules_jvm_external to mark the generated target for
com.squareup:javapoet with the neverlink = True attribute, making the
artifact available only for compilation and not at runtime.
If you want to mark certain artifacts as test-only dependencies, use the
testonly attribute in the maven.artifact helper:
load("@rules_jvm_external//:specs.bzl", "maven")
maven_install(
artifacts = [
maven.artifact("junit", "junit", "4.13", testonly = True),
],
# ...
)This instructs rules_jvm_external to mark the generated target for
junit:Junit with the testonly = True attribute, making the
artifact available only for tests (e.g. java_test), or targets specifically
marked as testonly = True.
Use the version_conflict_policy attribute to decide how to resolve conflicts
between artifact versions specified in your maven_install rule and those
implicitly picked up as transitive dependencies.
The attribute value can be either default or pinned.
default: use Coursier's default algorithm
for version handling.
pinned: pin the versions of the artifacts that are explicitly specified in maven_install.
For example, pulling in guava transitively via google-cloud-storage resolves to guava-26.0-android.
maven_install(
name = "pinning",
artifacts = [
"com.google.cloud:google-cloud-storage:1.66.0",
],
repositories = [
"https://repo1.maven.org/maven2",
]
)$ bazel query @pinning//:all | grep guava_guava
@pinning//:com_google_guava_guava
@pinning//:com_google_guava_guava_26_0_android
Pulling in guava-27.0-android directly works as expected.
maven_install(
name = "pinning",
artifacts = [
"com.google.cloud:google-cloud-storage:1.66.0",
"com.google.guava:guava:27.0-android",
],
repositories = [
"https://repo1.maven.org/maven2",
]
)$ bazel query @pinning//:all | grep guava_guava
@pinning//:com_google_guava_guava
@pinning//:com_google_guava_guava_27_0_android
Pulling in guava-25.0-android (a lower version), resolves to guava-26.0-android. This is the default version conflict policy in action, where artifacts are resolved to the highest version.
maven_install(
name = "pinning",
artifacts = [
"com.google.cloud:google-cloud-storage:1.66.0",
"com.google.guava:guava:25.0-android",
],
repositories = [
"https://repo1.maven.org/maven2",
]
)$ bazel query @pinning//:all | grep guava_guava
@pinning//:com_google_guava_guava
@pinning//:com_google_guava_guava_26_0_android
Now, if we add version_conflict_policy = "pinned", we should see guava-25.0-android getting pulled instead. The rest of non-specified artifacts still resolve to the highest version in the case of version conflicts.
maven_install(
name = "pinning",
artifacts = [
"com.google.cloud:google-cloud-storage:1.66.0",
"com.google.guava:guava:25.0-android",
],
repositories = [
"https://repo1.maven.org/maven2",
]
version_conflict_policy = "pinned",
)$ bazel query @pinning//:all | grep guava_guava
@pinning//:com_google_guava_guava
@pinning//:com_google_guava_guava_25_0_android
There may be cases where you want the default pinning strategy, but
want one specific dependency to be pinned, no matter what. In these
cases, you can use the force_version attribute on the
maven.artifact helper to ensure this happens.
maven_install(
name = "forcing_versions",
artifacts = [
# Specify an ancient version of guava, and force its use. If we try to use `[23.3-jre]` as the version,
# the resolution will fail when using `coursier`
maven.artifact(
artifact = "guava",
force_version = True,
group = "com.google.guava",
version = "23.3-jre",
),
# And something that depends on a more recent version of guava
"xyz.rogfam:littleproxy:2.1.0",
],
repositories = [
"https://repo1.maven.org/maven2",
],
)In this case, once pinning is complete, guava 23.3-jre will be selected.
You can override the generated targets for artifacts with a target label of your
choice. For instance, if you want to provide your own definition of
@maven//:com_google_guava_guava at //third_party/guava:guava, specify the
mapping in the override_targets attribute:
maven_install(
name = "pinning",
artifacts = [
"com.google.guava:guava:27.0-jre",
],
repositories = [
"https://repo1.maven.org/maven2",
],
override_targets = {
"com.google.guava:guava": "@//third_party/guava:guava",
},
)Note that the target label contains @//, which tells Bazel to reference the
target relative to your main workspace, instead of the @maven workspace.
The dependency that has been overridden is made available prefixed with
original_. That is, in the example above, the version of Guava that was
resolved could be accessed as @maven//:original_com_google_guava_guava.
The primary use case this is designed to support is to allow specific
targets to have additional dependencies added (eg. to ensure a default
implementation of key interfaces are available on the classpath without
needing to modify every target)
As with other Bazel repository rules, the standard http_proxy, https_proxy
and no_proxy environment variables (and their uppercase counterparts) are
supported.
Maven artifact rules like maven_jar and jvm_import_external generate targets
labels in the form of @group_artifact//jar, like @com_google_guava_guava//jar. This
is different from the @maven//:group_artifact naming style used in this project.
As some Bazel projects depend on the @group_artifact//jar style labels, we
provide a generate_compat_repositories attribute in maven_install. If
enabled, JAR artifacts can also be referenced using the @group_artifact//jar
target label. For example, @maven//:com_google_guava_guava can also be
referenced using @com_google_guava_guava//jar.
The artifacts can also be referenced using the style used by
java_import_external as @group_artifact//:group_artifact or
@group_artifact for short.
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
generate_compat_repositories = True
)
load("@maven//:compat.bzl", "compat_repositories")
compat_repositories()If the maven_jar or jvm_import_external is not named according to rules_jvm_external's
conventions, you can apply
repository remapping
from the expected name to the new name for compatibility.
For example, if an external dependency uses @guava//jar, and rules_jvm_external
generates @com_google_guava_guava//jar, apply the repo_mapping attribute to the external
repository WORKSPACE rule, like http_archive in this example:
http_archive(
name = "my_dep",
repo_mapping = {
"@guava": "@com_google_guava_guava",
}
# ...
)With repo_mapping, all references to @guava//jar in @my_dep's BUILD files will be mapped
to @com_google_guava_guava//jar instead.
As a convenience, transitive dependencies are visible to your build rules.
However, this can lead to surprises when updating maven_install's artifacts
list, since doing so may eliminate transitive dependencies from the build
graph. To force rule authors to explicitly declare all directly referenced
artifacts, use the strict_visibility attribute in maven_install:
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
strict_visibility = True
)It is also possible to change strict visibility value from default //visibility:private
to a value specified by strict_visibility_value attribute.
It is possible to retrieve full list of dependencies in the dependency tree, including
transitive, source, javadoc and other artifacts. maven_artifacts list contains full
versioned maven coordinate strings of all dependencies.
For example:
load("@maven//:defs.bzl", "maven_artifacts")
load("@rules_jvm_external//:defs.bzl", "artifact")
load("@rules_jvm_external//:specs.bzl", "parse")
all_jar_coordinates = [c for c in maven_artifacts if parse.parse_maven_coordinate(c).get("packaging", "jar") == "jar"]
all_jar_targets = [artifact(c) for c in all_jar_coordinates]
java_library(
name = "depends_on_everything",
runtime_deps = all_jar_targets,
)The default timeout to fetch and resolve artifacts is 600 seconds. If you need
to change this to resolve a large number of artifacts you can set the
resolve_timeout attribute in maven_install:
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
resolve_timeout = 900
)By default, if any fetched jar is empty (has 0 bytes) the corresponding artifact will still be included in the dependency tree.
If you would like to avoid such artifacts, and treat jars that are empty (i.e. their checksum equals the checksum of an
empty file) as if they were not found, you can set the ignore_empty_files attribute in maven_install to remove such
artifacts from coursier's output:
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
# ...
ignore_empty_files = True
)This option may be useful if you see empty source jars when fetch_sources is enabled.
By default you will be warned if there are duplicate artifacts in your artifact list. The duplicate_version_warning setting can be used to change this behavior. Use "none" to disable the warning and "error" to fail the build instead of warn.
maven_install(
artifacts = [
# ...
],
repositories = [
# ...
],
duplicate_version_warning = "error"
)You can set up COURSIER_OPTS environment variable to provide some additional JVM options for Coursier.
This is a space-separated list of options.
Assume you'd like to override Coursier's memory settings:
COURSIER_OPTS="-Xms1g -Xmx4g"Try to use OpenJDK explicitly if your machine or environment is set up to use a non-standard default implementation of the JDK and you encounter errors similar to the following:
java.lang.NullPointerException
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:58)
at java.base/jdk.internal.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)
at java.base/java.lang.reflect.Field.get(Field.java:418)
at org.robolectric.shadows.ShadowActivityThread$_ActivityThread_$$Reflector0.getActivities(Unknown Source)
at org.robolectric.shadows.ShadowActivityThread.reset(ShadowActivityThread.java:277)
at org.robolectric.Shadows.reset(Shadows.java:2499)
at org.robolectric.android.internal.AndroidTestEnvironment.resetState(AndroidTestEnvironment.java:640)
at org.robolectric.RobolectricTestRunner.lambda$finallyAfterTest$0(RobolectricTestRunner.java:361)
at org.robolectric.util.PerfStatsCollector.measure(PerfStatsCollector.java:86)
at org.robolectric.RobolectricTestRunner.finallyAfterTest(RobolectricTestRunner.java:359)
at org.robolectric.internal.SandboxTestRunner$2.lambda$evaluate$2(SandboxTestRunner.java:296)
at org.robolectric.internal.bytecode.Sandbox.lambda$runOnMainThread$0(Sandbox.java:99)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at java.base/java.lang.Thread.run(Thread.java:830)
or
java.lang.UnsatisfiedLinkError: libstdc++.so.6: cannot open shared object file: No such file or directory
at java.base/java.lang.ClassLoader$NativeLibrary.load0(Native Method)
at java.base/java.lang.ClassLoader$NativeLibrary.load(ClassLoader.java:2444)
at java.base/java.lang.ClassLoader$NativeLibrary.loadLibrary(ClassLoader.java:2500)
at java.base/java.lang.ClassLoader.loadLibrary0(ClassLoader.java:2716)
at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2629)
at java.base/java.lang.Runtime.load0(Runtime.java:769)
at java.base/java.lang.System.load(System.java:1840)
at org.conscrypt.NativeLibraryUtil.loadLibrary(NativeLibraryUtil.java:52)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
...
If you're writing a library that has dependencies, you should define a constant that lists all of the artifacts that your library requires. For example:
# my_library/BUILD
# Public interface of the library
java_library(
name = "my_interface",
deps = [
"@maven//:junit_junit",
"@maven//:com_google_inject_guice",
],
)# my_library/library_deps.bzl
# All artifacts required by the library
MY_LIBRARY_ARTIFACTS = [
"junit:junit:4.12",
"com.google.inject:guice:4.0",
]Users of your library can then load the constant in their WORKSPACE and add the
artifacts to their maven_install. For example:
# user_project/WORKSPACE
load("@my_library//:library_deps.bzl", "MY_LIBRARY_ARTIFACTS")
maven_install(
artifacts = [
"junit:junit:4.11",
"com.google.guava:guava:26.0-jre",
] + MY_LIBRARY_ARTIFACTS,
)# user_project/BUILD
java_library(
name = "user_lib",
deps = [
"@my_library//:my_interface",
"@maven//:junit_junit",
],
)Any version conflicts or duplicate artifacts will resolved automatically.
In order to publish an artifact from your repo to a maven repository, you
must first create a java_export target. This is similar to a regular
java_library, but allows two additional parameters: the maven coordinates
and an optional template file to use for the pom.xml file.
# user_project/BUILD
load("@rules_jvm_external//:defs.bzl", "java_export")
java_export(
name = "exported_lib",
maven_coordinates = "com.example:project:0.0.1",
pom_template = "pom.tmpl", # You can omit this
srcs = glob(["*.java"]),
deps = [
"//user_project/utils",
"@maven//:com_google_guava_guava",
],
)If you wish to publish an artifact with Kotlin source code to a maven repository
you can use kt_jvm_export. This rule has the same arguments and generated
rules as java_export, but uses kt_jvm_library instead of java_library.
# user_project/BUILD
load("@rules_jvm_external//:kt_defs.bzl", "kt_jvm_export")
kt_jvm_export(
name = "exported_kt_lib",
maven_coordinates = "com.example:project:0.0.1",
srcs = glob(["*.kt"]),
)In order to publish the artifact, use bazel run:
bazel run --define "maven_repo=file://$HOME/.m2/repository" //user_project:exported_lib.publish
Or, to publish to (eg) Sonatype's OSS repo:
MAVEN_USER=example_user MAVEN_PASSWORD=hunter2 bazel run --stamp \
--define "maven_repo=https://oss.sonatype.org/service/local/staging/deploy/maven2" \
--define gpg_sign=true \
//user_project:exported_lib.publish`Or, to publish to a Google Cloud Storage:
bazel run --define "maven_repo=gs://example-bucket/repository" //user_project:exported_lib.publish
Or, to publish to an Amazon S3 bucket:
bazel run --define "maven_repo=s3://example-bucket/repository" //user_project:exported_lib.publish
Or, to publish to a GCP Artifact Registry:
bazel run --define "maven_repo=artifactregistry://us-west1-maven.pkg.dev/project/repository" //user_project:exported_lib.publish
When using the gpg_sign option, the current default key will be used for
signing, and the gpg binary needs to be installed on the machine.
rules_jvm_external supports different mechanisms for dependency resolution.
These can be selected using the resolver attribute of maven_install. The
default resolver is one backed by coursier.
All resolvers understand the following environment variables:
| Environment variable | Meaning |
|---|---|
RJE_VERBOSE |
When set to 1 extra diagnostic logging will be sent to stderr |
The default resolver is backed by coursier, which is used in tools such as sbt. It supports being used without a lock file, but cannot handle resolutions which require Maven BOMs to be used. When using the coursier-backed resolver, the following environment variables are honoured:
| Environment variable | Meaning |
|---|---|
COURSIER_CREDENTIALS |
Documented here on the coursier site. If set to an absolute path, this will be used for configuring the credentials |
A Maven-backed resolver can be used by using setting the resolver
attribute of maven_install to maven. This resolver requires the use of a
lock file. For bootstrapping purposes, this file may simply be an empty
file. When using the maven-backed resolver, the following environment
variables are honoured:
| Environment variable | Meaning |
|---|---|
RJE_ASSUME_PRESENT |
Prevents the resolver from checking remote repositories to see if a dependency is present, and just assumes it is |
RJE_MAX_THREADS |
Integer giving the maximum number of threads to use for downloads. The default value is whichever is lower: the number of processors on the machine, or 5 |
RJE_UNSAFE_CACHE |
When set to 1 will use your $HOME/.m2/repository directory to speed up dependency resolution |
Using the unsafe cache option will use your local $HOME/.m2/repository as
a source for dependency resolutions, but will not include any local paths in
the generated lock file unless the repositories attribute contains m2local.
The Maven-backed resolver will use credentials stored in a $HOME/.netrc
file when performing dependency resolution
Certain IPv4/IPv6 dual-stack environments may require flags to override the default settings for downloading dependencies, for both Bazel's native downloader and Coursier as a downloader:
Add:
startup --host_jvm_args=-Djava.net.preferIPv6Addresses=trueto your.bazelrcfile for Bazel's native downloader.-Djava.net.preferIPv6Addresses=true to theCOURSIER_OPTS` environment variable to provide JVM options for Coursier.
For more information, read the official docs for IPv6 support in Bazel.
Set the RJE_VERBOSE environment variable to true to print coursier's verbose
output. For example:
$ RJE_VERBOSE=true bazel run @maven//:pin
In order to run tests, your system must have an Android SDK installed. You can install the Android SDK using Android Studio, or through most system package managers.
$ bazel test //...
The instructions for installing the Android SDK on macOS can be hard
to find, but if you're comfortable using HomeBrew,
the following steps will install what you need and set up the
ANDROID_HOME environment variable that's required in order to run
rules_jvm_external's own tests.
brew install android-commandlinetools
export ANDROID_HOME="$(brew --prefix)/share/android-commandlinetools"
sdkmanager "build-tools;33.0.1" "cmdline-tools;latest" "ndk;21.4.7075529" "platform-tools" "platforms;android-33"
export ANDROID_NDK_HOME="$ANDROID_HOME/ndk/21.4.7075529"
You can add the export ANDROID_HOME to your .zshrc or similar
config file.
Use Stardoc to generate API documentation in the docs directory using generate_docs.sh.
