Issue with CodeBuild Runner for GitHub Actions – "YAML file does not exist"

It seems there might be a misunderstanding in how you've set up your CodeBuild project for GitHub Actions integration. When using CodeBuild as a self-hosted GitHub Actions runner, you don't need to manually create a webhook or configure it to trigger on pull requests. Instead, the process should be as follows:

1. Create a CodeBuild project specifically for hosting GitHub Actions runners.
2. In the project settings, under "Primary source webhook events", select "Rebuild every time a code change is pushed to this repository".
3. For the "Event type", choose "WORKFLOW_JOB_QUEUED". This is crucial as it ensures CodeBuild only processes GitHub Actions workflow jobs.

The "YAML file does not exist" error suggests that CodeBuild is trying to run a build directly, rather than acting as a GitHub Actions runner. This behavior indicates that the webhook might be incorrectly configured.

Regarding your questions:

1. You don't need to explicitly register the CodeBuild runner with your GitHub repository. The integration between CodeBuild and GitHub Actions is handled automatically when you set up the project correctly.

2. The runner registration is managed by CodeBuild when it's properly configured as a GitHub Actions runner. You don't need to handle this manually.

To resolve the issue:

1. Review your CodeBuild project settings and ensure you've selected "WORKFLOW_JOB_QUEUED" as the event type.

2. Make sure your GitHub Actions workflow YAML file includes the correct runner label. It should look something like this:

   runs-on:
     - codebuild-myProject-${{ github.run_id }}-${{ github.run_attempt }}

   Replace "myProject" with your actual CodeBuild project name.

3. If you've manually set up webhooks in your GitHub repository settings, remove them and let CodeBuild handle the webhook creation.

4. Ensure your GitHub Actions workflow file is properly formatted and located in the correct directory (.github/workflows) in your repository.

By following these steps, CodeBuild should correctly function as a self-hosted GitHub Actions runner without requiring a buildspec file or manual runner registration.

Sources
Self-hosted GitHub Actions runners in AWS CodeBuild - AWS CodeBuild
AWS CodeBuild Managed Self-Hosted GitHub Action Runners | AWS DevOps & Developer Productivity Blog
Label overrides supported with the CodeBuild-hosted GitHub Actions runner - AWS CodeBuild

I can only see these options on my console

I was able to run the workflow by selecting the "workflow jobs" option. I checked "Pull requests," which triggered two builds. One build ran successfully with the workflow job, but the other one encountered an error stating, "YAML file does not exist."