How To Build a CI/CD Pipeline With GitHub Actions And .NET

Do you want to streamline your software development process and accelerate your release cycles?

Imagine being able to automatically build, test, and deploy your .NET applications with every code change.

With CI/CD, you can significantly reduce manual effort and focus more on creating software, ensuring faster and more reliable releases.

And it's never been easier to get started with CI/CD.

GitHub Actions are completely free and simple to use.

So here's what we'll cover:

Introduction to CI/CD & GitHub Actions
Creating a build & test pipeline for .NET
Creating a deployment pipeline for Azure App Service

Let's dive in!

What Is Continuous Integration And Delivery?

I'll try to briefly explain what CI/CD is, before we take a look at GitHub Actions.

CI/CD is a method to increase the frequency of delivering new features by adding automation to your software development workflow.

Continuous Integration ("CI") refers to the automation process of syncing new code to a repository. Any new changes to the application code are immediately built, tested and merged.

Continuous Delivery, or Deployment, ("CD") refers to the process of automating the deployment part of the workflow. When you make a change which gets merged to the repository, this step takes care of deploying those changes to the production environment (or any other environment).

Continuous Integration With GitHub Actions

If you're using GitHub, getting started with Continuous Integration has never been easier.

You can use GitHub Actions to automate your build, test, and deployment pipeline. You can create workflows that build and test every commit to your repository, or deploy to production when a new tag is created.

To create a GitHub Action, you write a workflow to be triggered when some event occurs in your repository. An example event is a commit to the main branch, creation of a tag, or you can manually run the workflow.

Here's a GitHub Actions workflow to build and test a .NET project:

name: Build & Test 🧪

on:
  push:
    branches:
      - main

env:
  DOTNET_VERSION: '7.0.x'

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v3

      - name: Setup .NET 📦
        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: ${{ env.DOTNET_VERSION }}

      - name: Install dependencies 📂
        run: dotnet restore WebApi

      - name: Build 🧱
        run: dotnet build WebApi --configuration Release --no-restore

      - name: Test 🧪
        run: dotnet test WebApi --configuration Release --no-build

Let's unwrap what is happening here:

Defining an event to trigger the workflow
Setting up the .NET SDK with the version from env.DOTNET_VERSION
Restoring, building and testing the project using the dotnet CLI tool

You can add this to your GitHub repository today, and start getting instant feedback when you commit code to the repository.

When a workflow run fails due to a build error or a failed test, you'll get an email notification.

Continuous Delivery To Azure With GitHub Actions

Continuous Integration is a great way to start out with CI/CD, but the real value lies in automating your deployment process.

Imagine this:

You make a change to your codebase
The commit triggers the deployment pipeline
A few minutes later your changes are live in production

Usually it's a little more nuanced, because we need to think about configuration, database migrations, etc. But try to see the big picture here.

If you're running your application in the cloud, for example on Azure, chances are there's an existing GitHub Action you can use.

Here's a deployment pipeline I use to publish my application to an Azure App Service instance:

name: Publish 🚀

on:
  push:
    branches:
      - main

env:
  AZURE_WEBAPP_NAME: web-api
  AZURE_WEBAPP_PACKAGE_PATH: './publish'
  DOTNET_VERSION: '7.0.x'

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v3

      - name: Setup .NET 📦
        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: ${{ env.DOTNET_VERSION }}

      - name: Build and Publish 📂
        run: |
          dotnet restore WebApi
          dotnet build WebApi -c Release --no-restore
          dotnet publish WebApi -c Release --no-build
            --output '${{ env.AZURE_WEBAPP_PACKAGE_PATH }}'

      - name: Deploy to Azure 🌌
        uses: azure/webapps-deploy@v2
        with:
          app-name: ${{ env.AZURE_WEBAPP_NAME }}
          publish-profile: ${{ secrets.AZURE_PUBLISH_PROFILE }}
          package: '${{ env.AZURE_WEBAPP_PACKAGE_PATH }}'

This workflow is pretty similar to the previous one, with the differences being:

Adding a publish step and configuring the output path
Using the azure/webapps-deploy@v2 action to deploy to Azure

If you need to safely and securely expose secret values in your workflows, you can use GitHub secrets. You can define the secrets on GitHub, and use them in actions without having to add them to source control.

In the deployment workflow I'm using secrets.AZURE_PUBLISH_PROFILE to access my publish profile for the App Service instance.

In Summary

Continuous Integration and Delivery can transform your development process by increasing the speed at which you release changes.

Try adding up how much time you spend on deployments. I'm pretty sure you'll be surprised by the time savings potential of automating them.

And the good part is you will typically set up your build and deployment pipelines once, and then continue benefiting from them for the lifetime of your project.

If you want a step by step guide, I made a video showing how to implement a CI/CD pipeline from scratch. And the source code is also public, so you can add the GitHub Actions workflow file to your project.

Thanks for reading.

Hope that was helpful!

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