Configuring Bazel CI to test Bazel rules for remote execution
This document is for owners and maintainers of Bazel rule repositories. It describes how to configure the Bazel Continuous Integration (CI) system for your repository to test your rules for compatibility against a remote execution scenario. The instructions in this document apply to projects stored in GitHub repositories.
Before completing the steps in this document, ensure the following:
- Your GitHub repository is part of the Bazel GitHub organization.
- You have configured Buildkite for your repository as described in Bazel Continuous Integration.
Setting up the Bazel CI for testing
.bazelci/presubmit.ymlfile, do the following:
a. Add a config named
b. In the
rbe_ubuntu1604config, add the build and test targets you want to test against remote execution.
bazel-toolchainsGitHub repository to your
WORKSPACEfile, pinned to the latest release. Also add an
rbe_autoconfigtarget with name
load("@bazel_toolchains//rules:rbe_repo.bzl", "rbe_autoconfig") # Creates toolchain configuration for remote execution with BuildKite CI # for rbe_ubuntu1604. rbe_autoconfig(name = "buildkite_config")
Send a pull request with your changes to the
presubmit.ymlfile. (See example pull request.)
To view build results, click Details for the RBE (Ubuntu 16.04) pull request check in GItHub, as shown in the figure below. This link becomes available after the pull request has been merged and the CI tests have run. (See example results.)
(Optional) Set the bazel test (RBE (Ubuntu 16.04)) check as a test required to pass before merging in your branch protection rule. The setting is located in GitHub in Settings > Branches > Branch protection rules, as shown in the following figure.
Troubleshooting failed builds and tests
If your build or tests fail, it’s likely due to the following:
Required build or test tools are not installed in the default container. Builds using the
rbe_ubuntu1604config run by default inside an
rbe-ubuntu16-04container, which includes tools common to many Bazel builds. However, if your rules require tools not present in the default container, you must create a custom container based on the
rbe-ubuntu16-04container and include those tools as described later in this document.
Build or test targets are using rules that are incompatible with remote execution. See Adapting Bazel Rules for Remote Execution for details about compatibility with remote execution.
Using a custom container in the
rbe_ubuntu1604 CI config
rbe-ubuntu16-04 container is publicly available at the following URL:
You can pull it directly from Container Registry or build it from source. The next sections describe both options.
Before you begin, make sure you have installed
If you are building the container from source, you must also install the latest
version of Bazel.
rbe-ubuntu16-04 from Container Registry
To pull the Pull the
from Container Registry, run the following command:
gcloud docker -- pull gcr.io/cloud-marketplace/google/rbe-ubuntu16-04@sha256:<sha256-checksum>
<sha256-checksum> with the SHA256 checksum value for
the latest container.
rbe-ubuntu16-04 container from source
To build the
rbe-ubuntu16-04 container from source, do the following:
git clone https://github.com/bazelbuild/bazel-toolchains
Set up toolchain container targets and build the container as explained in Toolchain Containers.
Pull the freshly built container:
gcloud docker -- pull gcr.io/<project-id>/<custom-container-name>@sha256:<sha256-checksum>
Running the custom container
To run the custom container, do one of the following:
If you pulled the container from Container Registry, run the following command:
docker run -it gcr.io/cloud-marketplace/google/rbe-ubuntu16-04@sha256:<sha256-checksum> /bin/bash
sha256-checksumwith the SHA256 checksum value for the latest container.
If you built the container from source, run the following command:
docker run -it gcr.io/<project-id>/<custom-container-name>@sha256:<sha256sum> /bin/bash
Adding resources to the custom container
rules_docker to add resources or
alternate versions of the original resources to the
If you are new to Docker, read the following:
For example, the following
Dockerfile snippet installs
FROM gcr.io/cloud-marketplace/google/rbe-ubuntu16-04@sha256:<sha256-checksum> RUN apt-get update && yes | apt-get install -y <my_tool_package>
Pushing the custom container to Container Registry
Once you have customized the container, build the container image and push it to Container Registry as follows:
Build the container image:
docker build -t <custom-container-name> .docker tag <custom-container-name> gcr.io/<project-id>/<custom-container-name>
Push the container image to Container Registry:
gcloud docker -- push gcr.io/<project-id>/<custom-container-name>
Navigate to the following URL to verify the container has been pushed:
Take note of the SHA256 checksum of your custom container. You will need to provide it in your build platform definition later in this document.
Configure the container for public access as described in publicly accessible as explained in Serving images publicly.
For more information, see Pushing and Pulling Images.
Specifying the build platform definition
You must include a Bazel platform configuration in your
custom toolchain configuration, which allows Bazel to select a toolchain
appropriate to the desired hardware/software platform. To generate
automatically a valid platform, you can add to your
rbe_autoconfig target with name
buildkite_config which includes additional
attrs to select your custom container. For details on this setup please read
the up-to-date documentation for