rules_copybara

A Bazel rule that wraps Copybara, a google-built tool for working with multiple repos

Installation

add this to your repo’s WORKSPACE file (bazel 5.3.1)

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

# TODO this chunk is wrong for external consumption, it should be a git_repository or http_archive with a release
local_repository(
    name = "com_github_rules_copybara",
    path = "."
)


load("@com_github_rules_copybara//:copybara.bzl", "copybara_config")

copybara_config(
    copybara_version = "6cd6432036fd47ba13737aa2ab3703ebf7a8a8cb",
    copybara_sha256 = "6601b287c39a08eb5c6e5ed15c920ed2bfeb9140220190ef29c117f2abe5b55d"
)

load("@com_github_rules_copybara//:copybara_dependencies.bzl", "copybara_dependency")

copybara_dependency()

load("@com_github_google_copybara//:repositories.bzl", "copybara_repositories")

copybara_repositories()

load("@com_github_google_copybara//:repositories.maven.bzl", "copybara_maven_repositories")

copybara_maven_repositories()

load("@com_github_google_copybara//:repositories.go.bzl", "copybara_go_repositories")

copybara_go_repositories()

Usage

Getting started

Follow the instructions in the Installation section

Examples

External repository pulled in to source tree

a simple example

in scalaz3.sky

core.workflow(
    name = "z3",
    origin = git.origin(
        url = "https://github.com/Z3Prover/z3.git",
        ref = "z3-4.11.2",
    ),
    origin_files = glob(["**"]),
    destination = folder.destination(),
    destination_files = glob(["**"]),
    authoring = authoring.pass_thru("z3 copybara update <[email protected]>"),
    transformations = [
        patch.apply(patches = ["examples/z3.patch"], strip = 0),
    ],
)

and the rule invocation in a BUILD file

copybara(
    name = "z3-copybara-import", # name of the rule
    additional_files = ["//examples:z3.patch"], # additional files you may need
    destination_dir = "3rdparty/copybara/z3", # to land in the source tree of the repo with this BUILD file
    workflow_defs = "//examples:z3.sky", # the workflow definition
    workflows = ["z3"], # select which workflows to run
)

a (slightly) more complex example

in scalaz3.sky

core.workflow(
    name = "scalaz3",
    origin = git.origin(
        url = "https://github.com/epfl-lara/ScalaZ3.git",
        ref = "f0869281a7a42a1ed336b9e9259518c0c75acaa9",
    ),
    origin_files = glob(["**"], exclude = ["build.sbt", "project"]),
    destination = folder.destination(),
    destination_files = glob(["**"]),
    authoring = authoring.pass_thru("scalaz3 copybara update <[email protected]>"),
    transformations = [
        patch.apply(patches = ["examples/scalaz3.patch"], strip = 0),
        core.replace(
            before = """import org.scalatest.{FunSuite, Matchers}""",
            after = """import org.scalatest.funsuite.AnyFunSuite\nimport org.scalatest.matchers.should.Matchers""",
            paths = glob(["src/test/**/*.scala"]),
        ),
        core.replace(
            before = "extends FunSuite",
            after = "extends AnyFunSuite",
            paths = glob(["src/test/**/*.scala"]),
        ),
    ],
)

and the corresponding build target

copybara(
    name = "scalaz3-copybara-import",
    additional_files = ["//copybara/workflow_files:scalaz3.patch"],
    destination_dir = "3rdparty/copybara/scalaz3",
    workflow_defs = "//copybara/workflow_files:scalaz3.sky",
    workflows = ["scalaz3"],
    deps = [":z3-copybara-import"]
)

STRT Push out a folder to an external repository

STRT Synchronize pull requests from an external GitHub repository

Things to keep in mind

• Copybara does not have CI on its repo, so not all commit hashes work.
• Copybara includes bazel’s source tree itself in its dependencies, and not all versions of bazel can build bazel. At the time of writing, latest master works only on bazel 6.0.0, whereas the version I use (since i’m on bazel 5.3.1) works with commit 6cd64320

Contributing

Authors

• Dhasharath Shrivathsa <[email protected]>
• Shaan Hashmi <[email protected]>