GitHub Actions

What are GitHub Actions?

GitHub Actions is a CI/CD solution that enables engineers to automate end-to-end DevOps operations, so they are performed every time code is pushed into the Git repository. Thus, building, testing, and deployment stages occur automatically every time new code is pushed to the common repository. 

Engineers can leverage GitHub Actions to create workflows with all the stages mentioned above and more based on the needs of their applications. Thus, GitHub Actions allows customization and goes beyond the DevOps lifecycle to run code based on applications’ other events. 

All major operating systems such as Linux, Windows, Ubuntu, and macOS support GitHub Actions. The platform supports various coding languages such as Rust, .NET, Java, Ruby, PHP, Go, Node.js, Python, and more. A few common alternatives to GitHub Actions are Jenkins, GitLab, and CircleCI.

Components of GitHub Actions

GitHub Actions’ CI/CD pipeline comprises five primary components; each has a specific function and operates at different stages of the DevOps lifecycle as given below:

Workflows

A workflow is a process engineers can configure to perform a specific task. For example, if building and testing are one set of tasks, the workflow helps engineers design a workflow and determine whether a specific event will trigger it, whether the tasks will run based on a time schedule, or if the tasks will be carried out manually. 

Although these are three examples, engineers can create a workflow with a high degree of personalization. At any point, many workflows can run simultaneously, performing different tasks.

Events

An event refers to any activity that triggers a workflow. If a workflow performs building and testing operations every time code is pushed onto the repository, the pushing of the code is an event. Numerous other events can trigger a workflow based on how engineers design them.

Jobs

Jobs are a series of steps in a workflow. Every job is independent of the other, but engineers can create interdependent jobs. However, one must ensure they are configured in chronological order. Furthermore, all steps in a job run on a single runner. 

Actions

An action is a complex task that must repeatedly run at regular intervals. Engineers can use certain default actions from GitHub Actions, and they can also write different kinds of actions based on their requirements. 

Runners

A runner is a server that runs the jobs within workflows. A runner can run only one job at any given time, but multiple runners can operate simultaneously. These servers can also be in the form of virtual machines, and engineers can configure and host their own runners on their hardware equipment.

Sample Workflow

Below is a sample ‘Hello World’ workflow, which uses all the above components of GitHub Actions.

on:
  push:
    branches:
      - main
jobs:
  print_hello:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Hello World!"

With the above workflow, the text ‘Hello World!’ will be printed once the workflow is executed. 

  • Workflows are written YAML files, which must be stored under the directory, .github/workflows.
  • Under the on: section, we add events, and in this case, the event is pushed. The event is linked to a specific branch, i.e., main, which means the code will be pushed to the main branch.
  • Under the jobs section is the code which details the operation, and in this case, it is to return the output: ‘Hello World!’
  • Once the code is pushed, the workflow is added to the Actions section of GitHub Actions.
  • One can simply go to the Workflow run section and click on print_hello. Once this is done, your workflow will run, and you’ll see the output on the screen. 

This is an elementary example of how workflows function. In reality, workflows are far more complex, and engineers can build them for various app functions.

Benefits of Using GitHub Actions

  • End-to-end Operations of GitHub Flow: GitHub Actions provides all operations of the overall GitHub flow, which streamlines the operations for DevOps engineers as they have a one-stop solution.
  • Automation: GitHub Actions automates all pipeline operations, reducing engineers’ manual work and redundancy of tasks. It protects from human error which is always a risk in manual tasks. 
  • User Management: The platform enables administrators to manage the users, their permissions, tokens and workflow.
  • Additions of Tools and Services: GitHub Actions has diverse tools and functionalities in the marketplace that enhance and elevate app workflows.
  • Reviews and Testing: The process of checking the code for vulnerabilities and issues becomes automated and takes place at an early stage of the software development lifecycle, well before deployment.
  • Project Monitoring: GitHub Actions allows engineers to monitor the various workflows and jobs in real-time. Thus, if any issue occurs, the DevOps team can troubleshoot and solve it in less time. 

GitHub Actions vs Alternative CI/CD Solutions

GitHub Actions vs Jenkins

GitHub Actions and Jenkins are both incredible CI/CD solutions. Each has its pros and cons. GitHub Actions is far more user-friendly and has a flatter learning curve for engineers, while Jenkins has a more significant learning curve. That said, GitHub Actions is more recent and has limitations in terms of community support. In contrast, Jenkins has far more robust solutions since the tool has existed for longer.

GitHub Actions vs GitLab

GitHub Actions and GitLab are both equally incredible, but the former is a better alternative if the organization is looking for a tool beyond DevOps operations. As mentioned earlier, GitHub Actions goes beyond the workflows of DevOps and hence helps engineers access all operations on one platform. 

GitHub Actions vs CircleCI

GitHub Actions’ free version is slightly more restrictive than CircleCI in terms of the compute time it offers. Furthermore, GitHub Actions is not compatible with external repositories, but only those on GitHub, whereas CircleCI is more compatible, supporting many repositories, among them GitHub and Bitbucket. However, GitHub Actions is relatively more secure since it is more tightly integrated with the GitHub repositories than CircleCI.

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