GH-200 GitHub Actions Exam Questions and Answers

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.

GitHub-hosted runners have a limit on the number of concurrent workflows (typically 20 for free-tier accounts and 5 for enterprise). If your organization needs to run more workflows simultaneously, you would need to use self-hosted runners to increase the available concurrency.

Self-hosted runners allow you to configure specialized hardware or software setups that are necessary for certain workflows. GitHub-hosted runners may not have access to custom hardware configurations like GPUs or other specialized resources, so self-hosted runners are required in such cases.

The action.yml file is the metadata file in a custom GitHub Action that defines the main entry point, including information such as the inputs, outputs, description, and the runs key that specifies the main entry point (e.g., a script or a Docker container).

To use a starter workflow provided by your organization, you need to go to the Actions tab in the repository and select New workflow. This option allows you to either create a new workflow or select from a list of available workflow templates, including starter workflows provided by your organization.

First, the dataset should be encrypted before being stored. This ensures that the data is protected when stored in a repository.

The encrypted dataset can be stored in a GitHub secret, ensuring it is securely kept and not exposed publicly.

The encryption key needed to decrypt the dataset should also be stored in a GitHub secret to maintain security during the workflow, allowing access only when needed.

Dockerfile: The Dockerfile is required for Docker container actions. It defines the environment for the action, specifying the base image, dependencies, and any commands to set up the action’s runtime inside the container.

action.yml: The action.yml file is required for all GitHub Actions, including Docker container actions. It contains metadata about the action, including the inputs, outputs, and the runtime environment (which in this case is Docker, defined under runs.using).

The needs context is used to reference the outputs of jobs that are dependencies of the current job. In this case, needs.job1.outputs.output1 correctly accesses the output of output1 from the job job1 in the dependent job.

GitHub Actions on GitHub Enterprise Server often requires an internet connection, especially for accessing actions from the GitHub Marketplace or third-party actions unless they are manually synced to the server.

To use third-party actions on GitHub Enterprise Server, GitHub Connect can be used to establish a connection between the server and GitHub.com, enabling access to third-party actions.

Third-party actions can also be manually synchronized to the GitHub Enterprise Server, making them available for use in workflows.

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.

Creating a separate repository for each custom action allows you to manage the versioning independently for each action. This approach provides flexibility, as each action can be updated, tested, and versioned separately, avoiding potential conflicts or dependencies between different actions.

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.

GitHub secrets are defined at different levels: organization, repository, and sometimes at the workflow level. If a secret is defined at both the organization level and the repository level, the repository-level secret will take precedence. So, if the value of the secret differs between these levels, the workflow will use the value from the repository level instead of the organization level.

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.

Job outputs are used to pass data from one job to another in a workflow. A job can produce output values (like variables or files), which can be referenced by subsequent jobs using the needs keyword and ${{ steps.step_id.outputs.output_name }} syntax.

Artifact storage allows data (such as files or results) to be saved by a job and then retrieved by another job in a later step. This is commonly used for passing large amounts of data or files between jobs.

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.

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.

Some actions may require a GITHUB_TOKEN as an input to authenticate and perform specific tasks, such as creating issues, commenting on pull requests, or interacting with the GitHub API. In such cases, you would need to explicitly pass the token to the action.

When making an authenticated GitHub API request, the GITHUB_TOKEN is required to authenticate the request. This token is automatically provided by GitHub in the workflow, and it must be explicitly used when interacting with the GitHub API.

While Docker can run on various operating systems, Linux is often the most common and preferred OS for containerized workloads. Docker works well on Linux and is a widely-used platform for running containers.

For container jobs to run on a self-hosted runner, Docker must be installed and properly configured on the runner. Docker is required to build and run containerized workloads in a GitHub Actions workflow.