GH-200 Questions and Answers

Deleting artifacts from repositories manually will free up storage space. Artifacts are typically stored for a limited time by default, but manual cleanup can help manage space.

Configuring the artifact and log retention period allows you to control how long artifacts and logs are retained in your repository. By shortening the retention period, you can prevent unnecessary accumulation of data and manage storage more effectively.

Caching is ideal for files that change rarely, such as dependencies or build outputs, as it speeds up subsequent workflow runs by reusing previously cached files instead of re-downloading or rebuilding them.

Artifacts are used for persisting files produced during a job that need to be used in later jobs or after the workflow has ended, allowing them to be downloaded or referenced later.

A composite action allows you to bundle multiple steps into a single reusable action within a workflow. It is composed of multiple run steps or other actions and can be reused across workflows, making it the perfect choice for bundling a series of steps.

The correct minimal syntax for declaring an output in GitHub Actions is by using the foo key under outputs, and associating it with a value (in this case, Some value). This is the simplest form to define an output in a workflow or action.

The correct syntax includes specifying the job (example-job), the runner (ubuntu-latest), and the necessary step (npm install -g bats) within the workflow. This ensures that the package is installed properly during the execution of the job.

The GITHUB_ACTOR environment variable indicates the name of the person or app that initiated the workflow. This variable is automatically provided by GitHub in the workflow and can be used to identify the user or application triggering the workflow.

The repository_dispatch event allows you to trigger a workflow in response to external activity. It is commonly used when you need to trigger a workflow from outside GitHub, such as from another system or service, by sending a request to the GitHub API. This event provides flexibility to integrate with various external systems and trigger workflows in a GitHub repository.

For a Docker container action to run in a GitHub Actions workflow, the runner must have Docker installed. The runs-on attribute of the job should specify an environment that supports Docker, typically a Linux environment (e.g., ubuntu-latest), since Docker is widely supported and commonly used in Linux-based environments.

Workflow commands are special commands that allow you to interact with the runner, set environment variables, output values, add debug messages, and perform other tasks within the workflow. These commands are used to modify the environment or influence the behavior of the GitHub Actions runner.

To scope a secret to a specific repository, you can create a new secret with a name like MyRepo_SuperSecret in the secrets section of the MyRepo repository's settings. This ensures that the secret is specific to that repository and can be used within its workflows.

The provided event trigger block specifies two types of events:

For issues: the workflow triggers on opened or edited issues.

For issue_comment: the workflow triggers when an issue comment is created.

This configuration ensures the workflow will run when either an issue is opened or edited, or an issue comment is created.

GitHub Actions supports the use of service containers, which allows you to spin up a PostgreSQL database (or any other service) in a Docker container during your workflow. You can pull a PostgreSQL image from Docker Hub, and the container will automatically be available to your workflow job. This method requires no additional infrastructure and is easy to configure and maintain, as you simply define the container in the workflow file.

The core.warning() function from the @actions/core package is used to create a warning message in the workflow logs. This is an annotation type that informs users about issues that don't require failing the build but still need attention.

A matrix strategy allows you to define different versions of a programming language (or any other environment setting) and run tests on each version simultaneously. This is particularly useful for testing code compatibility across different versions of a language.

A matrix strategy can also be used to test code on multiple operating systems (e.g., Windows, macOS, Linux) by defining these operating systems as matrix variables. This enables cross-platform testing within the same workflow.

Using a tag is a best practice because tags are immutable and represent a fixed version of your action. By referencing tags, consumers of your action can be assured they are using a stable and specific version of the action, which helps in avoiding issues with breaking changes.

The commit SHA is another reliable way to specify a particular version of an action. By referencing a specific commit SHA, consumers can ensure they are using exactly the code that was written at that moment, avoiding the potential for changes in the future.

GITHUB_WORKSPACE is a default environment variable in GitHub Actions that points to the directory on the runner where your repository is checked out. This variable allows you to access files within your repository during the workflow.