GitHub Actions basics - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of a GitHub Actions workflow run command

What is the output of the following GitHub Actions command when triggered in a workflow?

Git

echo "Hello from GitHub Actions!"

A Hello from GitHub Actions!

B echo Hello from GitHub Actions!

C Error: command not found

D No output

💡 Hint

Think about what the echo command does in a shell environment.

The echo command prints the text string to the standard output, so the output will be exactly the string inside the quotes.

🧠 Conceptual

intermediate

Understanding GitHub Actions workflow triggers

Which event triggers a GitHub Actions workflow when a pull request is opened?

A pull_request

B release

C push

D issue_comment

💡 Hint

Think about the event name that relates to pull requests.

The 'pull_request' event triggers workflows when pull requests are opened, synchronized, or closed.

❓ Configuration

advanced

Correct syntax for a GitHub Actions job with multiple steps

Which option shows the correct YAML syntax for a job named 'build' with two steps: one to checkout code and one to run a script?

Git

name: CI
on: push
jobs:
  build:
    runs-on: ubuntu-latest
    steps:

A

- uses: actions/checkout@v3
  - run: ./build.sh

B

steps:
  - uses: actions/checkout@v3
  - run: ./build.sh

C

- uses: actions/checkout@v3
    - run: ./build.sh

D

- uses: actions/checkout@v3
- run: ./build.sh

💡 Hint

Remember that each step is an item in a list with a dash and proper indentation.

Each step must start with a dash at the same indentation level. Option D correctly lists two steps with proper indentation and keys.

❓ Troubleshoot

advanced

Diagnosing a failed GitHub Actions workflow due to missing permissions

A workflow fails with an error saying it cannot access the repository contents. What is the most likely cause?

A The workflow is triggered on the wrong event.

B The workflow file is missing the 'permissions' key with 'contents: read'.

C The runner machine is offline.

D The YAML syntax is invalid.

💡 Hint

GitHub Actions requires explicit permissions to access repository contents.

Since GitHub changed default permissions, workflows need 'permissions: contents: read' to access repo files. Missing this causes access errors.

🔀 Workflow

expert

Order of steps execution in a GitHub Actions job

Given a job with these steps, what is the order in which they execute?

A 1,3,2,4

B 2,1,3,4

C 1,2,3,4

D 4,3,2,1

💡 Hint

Steps run in the order they are listed in the YAML file.

GitHub Actions executes steps sequentially from top to bottom in the order they appear.

Practice

1. What is the main purpose of GitHub Actions in a repository?

easy

A. To automate tasks like testing and deployment when events happen

B. To store large files in the repository

C. To manage user permissions on the repository

D. To create branches automatically

Solution

1. Step 1: Understand GitHub Actions role

   GitHub Actions automate workflows triggered by events such as code pushes or pull requests.

2. Step 2: Compare options with purpose

   Options B, C, and D describe other GitHub features, not automation tasks.

3. Final Answer:

   To automate tasks like testing and deployment when events happen -> Option A

4. Quick Check:

   Automation = A [OK]

Hint: GitHub Actions = automation triggered by events [OK]

Common Mistakes:

• Confusing GitHub Actions with file storage
• Thinking it manages user permissions
• Assuming it creates branches automatically

2. Which of the following is the correct location to place a GitHub Actions workflow file?

easy

A. .git/actions/

B. .github/workflows/

C. workflows/.github/

D. actions/workflows/

Solution

1. Step 1: Recall workflow file location

   GitHub Actions workflows must be stored in the .github/workflows/ directory in the repository.

2. Step 2: Verify other options

   Options B, C, and D do not match the required directory structure for workflows.

3. Final Answer:

   .github/workflows/ -> Option B

4. Quick Check:

   Workflow path = .github/workflows/ [OK]

Hint: Workflow YAML files go inside .github/workflows/ folder [OK]

Common Mistakes:

• Placing workflow files outside .github/workflows/
• Using incorrect folder names like .git or actions
• Confusing workflows folder location

3. Given this workflow snippet, what will happen when code is pushed to the main branch?

name: Test Workflow
on:
  push:
    branches:
      - main
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Build started"

medium

A. The workflow runs and prints 'Build started' on push to main

B. The workflow runs but does nothing on push to main

C. The workflow runs only on pull requests, not push

D. The workflow fails due to syntax error

Solution

1. Step 1: Analyze trigger event

   The workflow triggers on push events to the main branch as specified under 'on: push: branches: - main'.

2. Step 2: Check job steps

   The job named 'build' runs on ubuntu-latest and executes a step that runs the command echo "Build started".

3. Final Answer:

   The workflow runs and prints 'Build started' on push to main -> Option A

4. Quick Check:

   Push to main triggers echo output [OK]

Hint: Push to main triggers echo command in workflow [OK]

Common Mistakes:

• Thinking workflow triggers on pull requests only
• Assuming no output is printed
• Believing there is a syntax error

4. Identify the error in this workflow YAML:

name: CI
on: push
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - name: Run tests
        run: pytest
      - name: Deploy
        run: deploy.sh
        if: success()

medium

A. The 'if' condition syntax is incorrect; should be 'if: success()' without indentation

B. The 'steps' list is missing a dash before 'Deploy'

C. The 'if' condition is invalid; it should be 'if: ${{ success() }}'

D. The 'runs-on' key is misspelled

Solution

1. Step 1: Review 'if' condition syntax in GitHub Actions

   GitHub Actions requires expressions inside ${{ }} for conditions, so 'if: success()' is invalid syntax.

2. Step 2: Validate other parts

   'runs-on' is correctly spelled, and the steps list has proper dashes. Indentation is correct.

3. Final Answer:

   The 'if' condition is invalid; it should be 'if: ${{ success() }}' -> Option C

4. Quick Check:

   Conditions need ${{ }} syntax [OK]

Hint: Use ${{ }} for conditions in GitHub Actions [OK]

Common Mistakes:

• Omitting ${{ }} around conditions
• Misplacing dashes in steps list
• Misspelling 'runs-on'

5. You want a GitHub Actions workflow that runs tests only when code is pushed to the 'develop' branch or when a pull request targets 'develop'. Which 'on' configuration is correct?

hard

A. on:
push:
branches:
- develop
pull_request:
branches:
- main

B. on:
push:
branches:
- main
pull_request:
branches:
- develop

C. on:
push:
branches:
- main
pull_request:
branches:
- main

D. on:
push:
branches:
- develop
pull_request:
branches:
- develop

Solution

1. Step 1: Understand event triggers needed

   The workflow should trigger on push to 'develop' and on pull requests targeting 'develop'.

2. Step 2: Match branches in 'on' configuration

   on: push: branches: - develop pull_request: branches: - develop correctly specifies both push and pull_request events with branches set to 'develop'. Other options mix 'main' and 'develop' incorrectly.

3. Final Answer:

   on: push: branches: - develop pull_request: branches: - develop -> Option D

4. Quick Check:

   Push and PR on develop branch = C [OK]

Hint: Match branch names exactly in push and pull_request triggers [OK]

Common Mistakes:

• Mixing 'main' and 'develop' branches in triggers
• Omitting pull_request event
• Using incorrect indentation in YAML