Domain 2: Runners & Execution Environments

GitHub Actions · 42 questions

• What does 'ubuntu-latest' resolve to when used as a runs-on value for GitHub-hosted runners?
• When registering a self-hosted runner at the repository level, where do you find the registration token?
• You have a self-hosted runner with custom labels 'gpu' and 'production'. Which runs-on value correctly targets this runner?
• What is the primary security benefit of using ephemeral (just-in-time) self-hosted runners?
• What is the purpose of runner groups in GitHub Actions?
• How do you run all steps of a job inside a specific Docker container in GitHub Actions?
• In a GitHub Actions job that uses a PostgreSQL service container, how does the job connect to the database?
• Where can you find the complete list of software pre-installed on GitHub-hosted runners?
• Which context property identifies the operating system of the runner during a workflow run?
• What type of GitHub-hosted runners provides more CPU and RAM than the standard 2-core machines?
• What is the purpose of Actions Runner Controller (ARC) in a Kubernetes environment?
• After registering a self-hosted runner, what command starts the runner to listen for jobs?
• When diagnosing self-hosted runner issues, which secret enables verbose runner infrastructure logging?
• What environment variable points to the directory where tool installations (Node.js, Python, Java) are cached on GitHub-hosted runners?
• How can you find the IP address ranges used by GitHub-hosted runners to configure firewall allowlists?
• How many GitHub Actions minutes are included for free on public repositories?
• What is a key network limitation of GitHub-hosted runners that organizations with strict network policies must address?
• What directory does the GITHUBWORKSPACE environment variable point to?
• A self-hosted runner carries labels 'self-hosted', 'linux', and 'gpu'. Which runs-on value requires the runner to match all listed labels?
• A job defines a service container with key 'redis'. From a step running on the job's runner (not inside a job container), how do you typically reach Redis on port 6379?
• Which runs-on label selects a GitHub-hosted runner using the latest Ubuntu image GitHub provides for standard hosted runners?
• Which two properties of the 'runner' context are commonly used when composing OS-aware cache keys? (Choose two)
• You need every step of a job to run inside 'node:20-bookworm' instead of directly on the hosted VM filesystem. Which job key configures this?
• Which statement correctly contrasts RUNNERTEMP and GITHUBWORKSPACE on a GitHub-hosted runner?
• What is a defining characteristic of GitHub-hosted larger runners compared with standard GitHub-hosted runners?
• In a GitHub Organization, what is the primary purpose of placing self-hosted runners into a runner group with repository access controls?
• A self-hosted runner has labels 'self-hosted', 'linux', 'x64', and 'gpu-a100'. Which runs-on value targets only runners that have the gpu-a100 label (among matching hosts)?
• Your organization enabled GitHub-hosted larger runners for heavy builds. How do jobs typically select a larger runner?
• A job defines a Redis service container. Which configuration correctly maps port 6379 and waits for the service to be ready?
• A job sets 'container: node:20' and a service 'postgres'. From a step inside the job container, which hostname should connect to PostgreSQL?
• Administrators placed production self-hosted runners in a runner group named 'prod-runners' visible to selected repositories. How should a workflow job request a runner from that group?
• Which two statements correctly contrast GitHub-hosted and self-hosted runners? (Choose two.)
• A job must run inside a private image 'ghcr.io/acme/ci-node:20'. How do you supply registry credentials for the job container?
• You must compile a native ARM64 binary on GitHub-hosted infrastructure that provides ARM runners. What should drive runs-on selection?
• A job must run steps inside a private image registry.example.com/ci/python:3.12. How do you supply registry credentials for the job container?
• Your enterprise hosts GPU self-hosted runners in a runner group restricted to selected private repositories. What happens when a workflow in a non-allowed private repo targets those runner labels?
• A job defines services.redis with image redis:7. How should steps in the job typically reach Redis?
• A workflow compiles a large native codebase and exceeds CPU/memory on standard GitHub-hosted runners. What is a supported way to obtain more powerful GitHub-hosted compute?
• Besides repository allow lists on runner groups, which operational practice most reduces risk when self-hosted runners execute workflows that build untrusted pull requests?
• Which two statements about job-level container: configuration are true? (Choose two.)
• Your organization enabled a larger GitHub-hosted runner pool exposed through a runner group. Which runs-on form targets that pool using the group selector (when configured that way)?
• When a job uses container.image, how do steps typically access the repository files checked out by actions/checkout?