GH-200 Practice Questions

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.

A . Use the actions/setup-docker action

B . Authenticate to the GitHub Container Registry.

C . Build the container image.

D . Push the image to the GitHub Container Registry

E . Pull the image from the GitHub Container Registry.

Workflow files must be stored in the .github/workflows/ directory of the repository. This is the

standard location for GitHub Actions workflow files, and workflows in this directory are automatically

triggered by events defined in the file, such as pushes, pull requests, or other GitHub events.

The matrix configuration specifies two variables: color and animal. The color variable has 2 values

(green and pink), and the animal variable has 2 values (owl and magpie). This would result in 4

combinations (2 color values × 2 animal values). Additionally, the include section introduces two

more combinations (color: blue and animal: owl; color: pink and animal: magpie).

The GITHUB_REF environment variable specifies the branch or tag that triggered the workflow. It

contains the full reference to the branch or tag, such as refs/heads/main for a branch or

refs/tags/v1.0 for a tag.

Using a commit hash is the safest method because it

a specific point in time in the

repository’s history. This ensures that the action is locked to that exact version and will not be

affected by any future changes or modifications to the codebase. Even if the action is updated later,

your workflow will continue using the specific commit you referenced.

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.

If a workflow depends on an external service that is down, disabling the workflow temporarily will

prevent it from running and sending requests to the service, thus avoiding failed requests or

unnecessary retries.

If a workflow is causing a negative impact on external services by generating too many requests or

incorrect data due to a bug, temporarily disabling the workflow will stop this behavior while the

issue is fixed.

GitHub Actions allows you to configure environment protection rules, where you can require specific

users or teams to approve the deployment before the workflow proceeds to the next step. This

ensures that the required reviewers approve the workflow before any sensitive actions (such as

deployment) occur.

The GITHUB_TOKEN is automatically provided by GitHub in workflows and can be used to

authenticate API requests to GitHub, including publishing packages to GitHub Packages.

The GITHUB_TOKEN is also used to authenticate API requests for actions like creating issues,

commenting, or interacting with pull requests within the same repository.