Understanding DevOps and Continuous Integration

DevOps is a set of practices designed to build, test, and release code in small, frequent steps. One of the core practices of DevOps is continuous integration, which encourages developers to commit their code to a shared repository, often on a daily basis. Each commit triggers an automated workflow on a CI server, which can then notify developers of any issues that arise when integrating their changes. When a repository evolves in small steps like this, it prevents what is commonly known as "merge hell."

The Perils of 'Merge Hell'

Imagine a scenario where a back-end developer builds a new API for a product. Shortly after, a front-end developer starts working on a new user interface that will consume this API. Several months later, when it comes time to merge these features, they are found to be completely incompatible. The build fails, and now a significant amount of time and resources must be spent resolving these conflicts.

Let's explore how building a continuous integration pipeline can prevent such issues.

Building a CI Pipeline

For example, consider a Node.js web application. To deliver this application to customers, several commands need to be executed:

  • test
  • build
  • deploy

This entire process can be automated in the cloud using a CI service like GitHub Actions. First, a workflow is created and configured to run on every push to the master branch. This event triggers a job that executes on a Linux container in the cloud. The container is instructed on what to do through a series of steps.

Here is an example of what the workflow steps might look like in a configuration file:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Setup Node.js
      uses: actions/setup-node@v1
      with:
        node-version: '18.x'
    - run: npm install
    - run: npm test
    - run: npm run build
    - run: npm run deploy

Now, anytime code is committed to the master branch in this repository, this workflow will run automatically. If any of the steps fail, the faulty software will not be delivered to customers, and the team will be automatically notified that there is an issue that needs to be addressed.

Key Benefits of CI/CD

Ultimately, CI/CD offers two primary benefits:

  • Increased Velocity: It helps automate tasks that would otherwise have to be done manually by developers, which increases development speed.
  • Improved Code Quality: It also detects small problems early, before they can escalate into major disasters, resulting in higher overall code quality.