Simplified build workflows

Oct 13, 2025 by wbrum.org 48 views

Feature Request: Optimizing App Binary Builds for Efficient CI Workflows

Problem Statement

The current unit test and code coverage workflows in our CI pipeline are designed to run only when there are detected changes that could cause a test failure. However, the build workflows do not have this optimization, leading to significant CI time being wasted on PRs that are operating well outside the main app. This issue is particularly prevalent in CI workflows or scripts that are not directly related to the main app.

The Need for Efficient Build Workflows

In today's fast-paced development environment, efficient CI workflows are crucial for ensuring that code changes are reviewed and validated quickly. However, the current build workflows can sometimes add unnecessary delays to the CI process, especially when dealing with PRs that are not directly related to the main app. By introducing a detection mechanism to determine whether each build flavor needs to be rebuilt, we can significantly reduce the CI time and make our workflows more efficient.

Solution Overview

To address this issue, we propose introducing a detection mechanism that can determine whether each build flavor needs to be rebuilt. This mechanism will be similar to the test and coverage workflows, but with some key differences. Instead of wrapping the actual bazel build command, we will introduce a script that can take any Bazel target as input and return an indicator on whether the target needs to be rebuilt given changes in the local environment.

Implementation Details

The proposed solution involves creating a script that can be used to check whether a Bazel target needs to be rebuilt. This script will take a Bazel target as input and return an exit code of 0 if no rebuild is necessary, and an exit code of 1 if a rebuild is necessary. The build workflows will be updated to run this script as a pre-step and then check the result to determine whether to proceed with a rebuild or short-circuit.

Example Use Case

Here's an example of how the script can be used:

bazel run //scripts:check_whether_target_needs_rebuild -- //:oppia_dev

In this example, the script check_whether_target_needs_rebuild is run with the Bazel target //:oppia_dev as input. The script will return an exit code of 0 if no rebuild is necessary, and an exit code of 1 if a rebuild is necessary.

Benefits of the Proposed Solution

The proposed solution offers several benefits, including:

Reduced CI time: By introducing a detection mechanism to determine whether each build flavor needs to be rebuilt, we can significantly reduce the CI time and make our workflows more efficient.
Improved build accuracy: The proposed solution ensures that only necessary builds are performed, reducing the risk of unnecessary builds and improving the overall build accuracy.
Simplified build workflows: The proposed solution simplifies the build workflows by introducing a detection mechanism that can determine whether each build flavor needs to be rebuilt.

Alternatives Considered

While there are several alternatives to the proposed solution, we believe that this approach offers the best balance of efficiency, accuracy, and simplicity. Some of the alternatives considered include:

Wrapping the actual bazel build command: This approach would require significant changes to the existing build workflows and may introduce additional complexity.
Using a different build tool: This approach would require significant changes to the existing build workflows and may introduce additional complexity.

Conclusion

In conclusion, the proposed solution offers a efficient and accurate way to determine whether each build flavor needs to be rebuilt. By introducing a detection mechanism that can determine whether each build flavor needs to be rebuilt, we can significantly reduce the CI time and make our workflows more efficient. We believe that this approach offers the best balance of efficiency, accuracy, and simplicity and recommend implementing it in our CI pipeline.
Q&A: Optimizing App Binary Builds for Efficient CI Workflows

Frequently Asked Questions

We've received several questions about the proposed solution to optimize app binary builds for efficient CI workflows. Below, we've answered some of the most frequently asked questions.

Q: What is the main problem with the current build workflows?

A: The main problem with the current build workflows is that they do not have a detection mechanism to determine whether each build flavor needs to be rebuilt. This leads to unnecessary builds and significant CI time being wasted on PRs that are operating well outside the main app.

Q: How does the proposed solution work?

A: The proposed solution involves introducing a detection mechanism that can determine whether each build flavor needs to be rebuilt. This mechanism will be similar to the test and coverage workflows, but with some key differences. Instead of wrapping the actual bazel build command, we will introduce a script that can take any Bazel target as input and return an indicator on whether the target needs to be rebuilt given changes in the local environment.

Q: What is the benefit of using a script to check whether a Bazel target needs to be rebuilt?

A: Using a script to check whether a Bazel target needs to be rebuilt offers several benefits, including:

Improved build accuracy: The script ensures that only necessary builds are performed, reducing the risk of unnecessary builds and improving the overall build accuracy.
Reduced CI time: By introducing a detection mechanism to determine whether each build flavor needs to be rebuilt, we can significantly reduce the CI time and make our workflows more efficient.
Simplified build workflows: The script simplifies the build workflows by introducing a detection mechanism that can determine whether each build flavor needs to be rebuilt.

Q: How will the script be implemented?

A: The script will be implemented using a similar mechanism to the test and coverage workflows. The script will take a Bazel target as input and return an exit code of 0 if no rebuild is necessary, and an exit code of 1 if a rebuild is necessary.

Q: What are the benefits of using a detection mechanism to determine whether each build flavor needs to be rebuilt?

A: The benefits of using a detection mechanism to determine whether each build flavor needs to be rebuilt include:

Improved build accuracy: The detection mechanism ensures that only necessary builds are performed, reducing the risk of unnecessary builds and improving the overall build accuracy.
Reduced CI time: By introducing a detection mechanism to determine whether each build flavor needs to be rebuilt, we can significantly reduce the CI time and make our workflows more efficient.
Simplified build workflows: The detection mechanism simplifies the build workflows by introducing a detection mechanism that can determine whether each build flavor needs to be rebuilt.

Q: How will the proposed solution be implemented in our CI pipeline?

A: The proposed solution will be implemented in our CI pipeline by introducing a detection mechanism that can determine whether each build flavor needs to be rebuilt. The script will be run as a pre-step in the build workflows, and the result will be used to determine whether to proceed with a rebuild or short-circuit.

Q: What are the next steps in implementing the proposed solution?

A: The next steps in implementing the proposed solution include:

Implementing the script: The script will be implemented using a similar mechanism to the test and coverage workflows.
Testing the script: The script will be tested to ensure that it works correctly and returns the expected results.
Integrating the script into the CI pipeline: The script will be integrated into the CI pipeline, and the result will be used to determine whether to proceed with a rebuild or short-circuit.