CI/CD with GitHub Actions in Android Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

GitHub Actions Workflow Trigger Output

You have a GitHub Actions workflow configured to trigger on push events to the main branch only. What will happen if you push a commit to a branch named feature/login?

A The workflow will not run because the push is not to the main branch.

B The workflow will run because all push events trigger it.

C The workflow will run only if the commit message contains 'deploy'.

D The workflow will run but only after a manual approval.

💡 Hint

Check the event trigger conditions in the workflow YAML.

The workflow is set to trigger only on push events to the main branch. Pushing to other branches like feature/login does not trigger it.

❓ Configuration

intermediate

Correct Syntax for a Job in GitHub Actions

Which of the following YAML snippets correctly defines a job named build that runs on Ubuntu latest and executes a step to print 'Hello World'?

A

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Print greeting
        run: echo "Hello World"

B

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Print greeting
        command: echo "Hello World"

C

jobs:
  build:
    runs_on: ubuntu-latest
    steps:
      - name: Print greeting
        run: echo "Hello World"

D

jobs:
  build:
    runs-on: ubuntu-latest
    step:
      - name: Print greeting
        run: echo "Hello World"

💡 Hint

Check the exact keys required for jobs and steps in GitHub Actions YAML.

The correct keys are 'runs-on' for the runner and 'steps' for the list of steps. Each step uses 'run' to execute commands.

🔀 Workflow

advanced

Sequential Job Execution in GitHub Actions

You want to create a workflow with two jobs: build and test. The test job should run only after build completes successfully. Which configuration achieves this?

A

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: echo Build
  test:
    runs-on: ubuntu-latest
    steps:
      - run: echo Test

B

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: echo Build
  test:
    runs-on: ubuntu-latest
    depends_on: build
    steps:
      - run: echo Test

C

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: echo Build
  test:
    runs-on: ubuntu-latest
    after: build
    steps:
      - run: echo Test

D

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: echo Build
  test:
    runs-on: ubuntu-latest
    needs: build
    steps:
      - run: echo Test

💡 Hint

Look for the keyword that defines job dependencies in GitHub Actions.

The 'needs' keyword specifies that the 'test' job depends on the successful completion of the 'build' job.

❓ Troubleshoot

advanced

Diagnosing a Failed GitHub Actions Workflow

A GitHub Actions workflow fails with the error: Permission denied (publickey) when trying to push to the repository. What is the most likely cause?

A The runner machine does not have internet access.

B The workflow YAML syntax is incorrect causing authentication failure.

C The workflow is missing a valid SSH key or token with push permissions.

D The repository is archived and cannot accept pushes.

💡 Hint

Consider what is needed for GitHub Actions to push code back to the repo.

To push code, the workflow needs authentication via SSH key or a token with write permissions. Missing or invalid credentials cause this error.

✅ Best Practice

expert

Optimizing CI/CD Workflow for Android Kotlin Project

Which practice best improves build speed and efficiency in a GitHub Actions workflow for an Android Kotlin project?

A Run all tests and builds on every push to any branch without caching.

B Cache Gradle dependencies and build outputs between workflow runs.

C Use a self-hosted runner with minimal resources to save costs.

D Trigger workflows only manually to avoid unnecessary runs.

💡 Hint

Think about how to avoid downloading dependencies every time.

Caching Gradle dependencies and build outputs reduces build time by reusing previously downloaded files and compiled outputs.