Most Frequently Asked Github Actions Interview Questions

1. What is an example of a task you have automated using Github Actions?
2. What experience do you have with Github Actions?
3. How would you handle an unexpected error while running a Github Action?
4. How do you debug failed Github Actions?
5. Describe a time when a Github Action you created saved you time and energy.
6. What strategies have you used to optimize performance for a Github Action?
7. What systems have you integrated into Github Actions?
8. How familiar are you with YAML syntax for configuring Github Actions?
9. What means have you used to secure sensitive information when using Github Actions?
10. What tips do you have for someone new to Github Actions?
11. In what ways have you used Github Actions in the past to improve the development process?
12. What challenges have you faced when managing multiple Github Actions concurrently?

What is an example of a task you have automated using Github Actions?

Using GitHub Actions, you can automate virtually any task. Examples include automating software builds, running tests, deploying to staging or production environments, generating database migrations, and more.

To give a specific example, we can automate a software build using GitHub Actions. First, create a workflow file in the root of the repository. This file should contain the build instructions written in YAML.

For example, here is a workflow file for building a Node.js application:

name: Node CI

on: push

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Use Node.js
      uses: actions/setup-node@v1
      with:
        node-version: 12.x
    - run: npm ci
    - run: npm run build

In this workflow, we define a job named "build" that executes on Ubuntu Linux and runs the commands necessary to build a Node.js application. In our case, the two commands are "npm ci" and "npm run build". The former command installs required dependencies, while the latter actually builds the application.

Once this workflow has been configured, it can be triggered whenever a change is pushed to the repository. Each time this happens, GitHub Actions will execute the configured commands and run the build process.

GitHub Actions provides an easy and powerful way to automate tasks in your GitHub repositories, and the examples provided above are just a small portion of what is possible. With a few simple steps, you can easily configure powerful workflows to automate common tasks such as software builds and deployments.

What experience do you have with Github Actions?

I have experience setting up Github Actions for various automation tasks, such as building and deploying apps. For example, I can set up a Github Action to build an application and then deploy it to a cloud service provider like AWS.

Here is an example of a Github Action that builds a Node.js application:

name: Node.js CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Use Node.js
      uses: actions/setup-node@v1
      with:
        node-version: '12.x'
    - run: npm install
    - run: npm test
    - run: npm run build
    - run: npm deploy

With this Github Action, any time code is pushed to the repository, a Node.js application will be built, tested, and deployed automatically. This saves time and eliminates manual steps in the development process.

How would you handle an unexpected error while running a Github Action?

An unexpected error while running a Github Action can be handled using the following three-step process:

1. The first step is to identify the root cause of the error. This can be done by looking through the log files and diagnostic information generated by the action.
2. Once the root cause of the error is identified, the next step is to craft an appropriate solution such that the action can continue executing without any issues. Depending on the error, this could involve updating the configuration parameters of the action, tweaking the code, or modifying the service or environment in which the action is running.
3. Finally, it is important to thoroughly test the solution before deploying it. This can be done by running the action in a test environment and verifying that the expected output is obtained.

A sample code snippet for handling unexpected errors in a Github action is provided below:

try {
    // main code logic here
} catch (Error e) {
    // Identify cause of error
    // Craft appropriate solution
    // Test solution
}

How do you debug failed Github Actions?

Debugging failed Github Actions can be a challenging task. The best approach is to first analyze the error message that you receive and look for clues as to what may have caused the failure. You can then try to identify the root cause of the issue by running debugging commands, such as 'git status', 'git log' and 'git diff'. Additionally, you can use the GitHub Actions logs to help you trace issues and identify possible solutions.

To narrow down issues, you can also start with the configuration settings for the job and create smaller scripts that test each variable before rerunning the action. If further examination is needed, you should consider using a debugging framework such as the GitHub Actions Toolkit to help debug your code.

The following code snippet can be used as a starting point for debugging GitHub Actions:

  // Get the job's execution ID
  const executionId = github.context.runId;
 
  // Get the job's log
  const jobLog = await github.actions.getJobLog({
    owner: github.context.repo.owner,
    repo: github.context.repo.repo,
    job_id: executionId
  });

Once you have identified the root cause of the issue, you can implement changes accordingly and rerun the job to verify that the issue has been resolved.

Describe a time when a Github Action you created saved you time and energy.

One of the most valuable Github Actions I created is an automated process for creating a daily changelog. This Action saved me an immense amount of time and effort, allowing me to focus on more important matters.

Originally, I was manually creating a changelog every day by aggregating data from various sources, such as my commit history, bug tracking systems, and issue trackers. It was a very tedious and time-consuming task.

To automate this process, I created a GitHub Action that uses an open-source Node.js library called "gitlogger" to retrieve my commit history and other data from various sources. I then used the results to create a JSON file with a comprehensive list of all the changes made in the past day.

The code snippet for my Action is provided below. By running this Action daily, I am able to save time and energy in creating my changelog, allowing me to focus more resources on other tasks.

```
const gitlogger = require("gitlogger")

// Setup the options for the git logger
const options = {
  author: '<YOUR_GIT_HUB_USERNAME>',
  since: '1d' // Limit it to last day
}

// Get the commits and other info
const log = gitlogger(options);

// Create a json file with all the changelog data
fs.writeFileSync("changelog.json", JSON.stringify(log))
```

What strategies have you used to optimize performance for a Github Action?

In order to optimize performance for a Github Action, a few useful strategies can be implemented. Firstly, it is important to analyze the resources needed to run the action, and adjust the runtime environment settings accordingly. This includes checking the memory and processor settings, as well as allocating resources according to the specific requirements of the task.

Additionally, it is beneficial to use caching techniques to minimize re-execution of certain steps in the action. This can be done either directly in the code written for the action, or by using external tools like Redis or Memcached.

Furthermore, it is important to use appropriate branching and parallelization when possible to reduce the time spent waiting on blocking tasks. Finally, leveraging pre-built containers such as the ones available in the GitHub Container Registry can provide further optimization, as the script doesn't need to spend time building new images every time its executed.

Here is an example of setting up pre-built container with Docker:

```
FROM ghcr.io/myorg/mycontainer:latest

#add your action code goes here

CMD ["action.sh"]
```

What systems have you integrated into Github Actions?

Github Actions allows developers to integrate various systems with their development workflow. This includes services such as Slack, Trello, and Jira, but also system programming languages like Node.js, Go, Python, and PHP. The entire integration process is straightforward and consists of two steps: creating a workflow and setting up the desired system.

Creating a workflow is the first step and is done using YAML files. These files contain the instructions that the GitHub Action needs to follow in order to successfully connect the chosen system with the development workflow. The file stores the commands used to execute the system, and any environment variables needed to be input.

The second step is the actual setup of the system itself. Depending on the type of system being integrated, this can include creating an access token, creating a server, or installing relevant software. For example, if integrating a chat application such as Slack, you need to create an access token for it.

Once both steps are completed, your system is ready to go. From here, every action triggered by the development workflow will have the system integrated with it. With the help of Github Actions, developers can speed up their workflows and reduce errors.

Here's an example of a workflow set up using YAML:

name: 'Github Action Example'
on: push
jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v1
      - run: ./system.sh
      - env:
        SYSTEM_API_TOKEN: [null]

How familiar are you with YAML syntax for configuring Github Actions?

YAML is a data serialization language that can be used to define files for configuring Github Actions. Its syntax consists of various data types such as scalars, sequences, and mappings, as well as a number of structures. To create a workflow file for Github Actions, these must be combined in a specific syntax. The workflow file needs to define the jobs that will be executed and the steps in each job.

As an example, a basic action for running tests might look like this:

name: CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout code
      uses: actions/checkout@v2
    - name: Run tests
      run: |
        make test

This workflow provides a job named "build" that will run on Ubuntu machines and includes two steps. The first is to checkout the code from Github and the second is to run the tests. This is just a basic example, but by adding more steps and using conditionals you can control when and how the jobs are executed. YAML is an easy-to-learn language and once you understand its syntax you will be able to create complex workflows for Github Actions.

What means have you used to secure sensitive information when using Github Actions?

To secure sensitive information when using Github Actions, there are a few processes and methods that can be employed. Firstly, it is important to make sure that any information stored as part of a Github Action workflow is securely encrypted either before or during transmission. This can be done using Advanced Encryption Standard (AES) encryption algorithms, with a unique key for each user.

Secondly, to ensure that only certain authorized users have access to the Github Action workflow and the sensitive information stored within, access control rules can be applied.

For example, using authentication tokens and OAuth2.0, users must provide proof of identity via software tokens to access certain sensitive data. Finally, it is possible to integrate Github Actions with an external security-focused application such as CyberArk Application Identity Manager (AIM) or Cloudformation to perform security checks and validation prior to any changes being carried out on the GitHub repository.

To illustrate this, a simple code snippet to encrypt a message using AES can be as follows:

import base64
from Crypto.Cipher import AES

key = 'unique_key_12345678'
IV = 16 * '\x00'
mode = AES.MODE_CBC
encryptor = AES.new(key, mode, IV=IV)

text = 'This is an example text for encryption'
ciphertext = encryptor.encrypt(text)
encode_ciphertext = base64.b64encode(ciphertext)

print(encode_ciphertext)

What tips do you have for someone new to Github Actions?

If you're new to Github Actions, here are some tips to help you get up and running quickly:

1. Familiarize yourself with the basics of the workflow syntax. You should be able to identify and understand the structure of a Github Actions workflow. This will help you create your own workflows more easily.
2. Make sure that your code can be executed correctly by using an automated test suite. This will save you time and effort by ensuring that your code works correctly each time you commit it.
3. Utilize existing actions to get started quickly. In Github Actions, there are hundreds of pre-built actions that you can use to quickly set up various tasks and processes.
4. Take advantage of the documentation. Make sure to review the official documentation for Github Actions thoroughly to ensure that you have a complete understanding of the features and functionality available to you.

Lastly, here's a sample code snippet to help you get going:

name: CI on push

on:
  push:
    branches: [master]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2
    - name: Run a one-line script
      run: echo 'Hello, world!'
    - name: Run a multi-line script
      run: |
        echo Add other actions to build,
        echo test, and deploy your project.

In what ways have you used Github Actions in the past to improve the development process?

Generally speaking, I have used GitHub Actions to simplify the development process for various projects. It offers a flexible and customizable workflow system which allows developers to easily set up tasks that are triggered when certain events occur. This means that rather than manually running a command every time a code needs to be tested or deployed, I can simply set up an action that automatically runs whenever those events occur.

One specific example is using GitHub Actions to automate the deployment of code to a hosting platform. For this, I set up an action that would trigger when code was pushed to a designated branch, and then runs a script that contained an FTP command that deployed the code to the hosting platform.

Additionally, I have used GitHub Actions to run tests on my code to ensure it meets certain standards. This can be done by setting up an action to check the code every time it is pushed to the repository, and then running a script that runs the desired tests.

Here is an example code snippet for testing code using an action:

action "Run tests" {
  uses = "actions/npm@v1"
  args = ["test"]
}

What challenges have you faced when managing multiple Github Actions concurrently?

As a developer working with multiple concurrent Github Actions, one of the main challenges I have faced is managing the complexity of setting up and running multiple jobs at the same time. In order to ensure that each job is running properly and efficiently, it is necessary not only to set up the workflow correctly but also to have an understanding of how the different jobs interact with one another.

For example, when managing multiple concurrent Github Actions, I have had to consider the conditions for triggering certain jobs, the order in which the jobs should be executed, ensuring all jobs run in the required environment, and setting up the necessary dependencies for each job. These tasks can become complicated and time consuming if there are many different jobs that need to be managed.

In order to make it easier to manage the complexity of multiple Github Actions, I have found that creating a custom script which automates the setup process and executes each job in the correct environment, in the correct order, and ensuring all dependencies are setup beforehand, is extremely helpful.

For example, here is a code snippet which can be used to automate the setup of Github Actions:

// Setup the workflow 
workflow "My Workflow" {
  on = "push"
  resolves = ["Job 1", "Job 2"]
}

// Setup job 1 
action "Job 1" {
  uses = "./path/to/job"
  env = {
    SCRIPT_ENV = "development"
  }
}

// Setup job 2 
action "Job 2" {
  uses = "./path/to/job"
  needs = ["Job 1"]
  env = {
    SCRIPT_ENV = "production"
  }
}

This code snippet creates a workflow with two jobs, job 1 and job 2. Job 1 must be run in the development environment while job 2 must be run in production. The code snippet also ensures that job 2 depends on job 1, meaning the job will only run after job 1 is complete.

By writing this script, I have been able to greatly reduce the amount of time and complexity involved in setting up and managing multiple concurrent Github Actions.