Automating Your .NET Development with CI/CD Pipelines

Continuous Integration (CI) and Continuous Deployment/Delivery (CD) are foundational practices in modern DevOps. They enable faster, more reliable software releases by automating the build, test, and deployment processes. This tutorial will guide you through setting up a robust CI/CD pipeline for your .NET applications.

This tutorial assumes basic familiarity with .NET development, Git version control, and a cloud provider or hosting environment.

What is CI/CD?

Continuous Integration (CI): Developers frequently merge their code changes into a central repository, after which automated builds and tests are run. The goal is to detect integration issues as early as possible.

Continuous Deployment/Delivery (CD): Extends CI by automatically deploying all code changes to a testing and/or production environment after the build stage. Continuous Delivery ensures that code is always deployable, while Continuous Deployment automatically deploys every validated change to production.

Key Benefits of CI/CD for .NET

  • Faster Release Cycles: Automate repetitive tasks to ship features quicker.
  • Improved Code Quality: Early detection of bugs through automated testing.
  • Reduced Risk: Smaller, more frequent deployments are less risky than large, infrequent ones.
  • Increased Developer Productivity: Developers can focus on writing code, not manual deployment steps.
  • Consistent Environments: Ensure that deployments to all environments are standardized.

Setting Up Your CI/CD Pipeline

We'll use Azure DevOps as our CI/CD platform for this example, but the concepts are transferable to other tools like GitHub Actions, GitLab CI, Jenkins, etc.

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1. Version Control with Git

Ensure your .NET project is hosted in a Git repository. Azure Repos, GitHub, or GitLab are common choices. Push your code regularly.

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2. Create an Azure DevOps Project

If you don't have one, create a free Azure DevOps organization and a new project.

Create Azure DevOps Project
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3. Configure a Build Pipeline (CI)

In your Azure DevOps project, navigate to "Pipelines" and create a new pipeline. Connect it to your Git repository. Azure DevOps can often auto-detect .NET projects and suggest a starter YAML pipeline.

A typical .NET CI pipeline will include:

  • Checkout: Get the latest code from your repository.
  • Restore: Run dotnet restore to download NuGet packages.
  • Build: Compile your .NET project using dotnet build.
  • Test: Run your unit and integration tests with dotnet test.
  • Publish: Create build artifacts (e.g., published web application or executables) using dotnet publish.
  • Publish Artifacts: Upload the build output to Azure DevOps for later use in the release pipeline.
Diagram of a .NET CI pipeline

Here's a simplified example of a azure-pipelines.yml file:

trigger:
- main

pool:
  vmImage: 'ubuntu-latest'

steps:
- task: DotNetCoreCLI@2
  displayName: 'Restore NuGet Packages'
  inputs:
    command: 'restore'
    projects: '**/*.csproj'

- task: DotNetCoreCLI@2
  displayName: 'Build Project'
  inputs:
    command: 'build'
    projects: '**/*.csproj'
    arguments: '--configuration Release'

- task: DotNetCoreCLI@2
  displayName: 'Run Unit Tests'
  inputs:
    command: 'test'
    projects: '**/*[Tt]ests/*.csproj'
    arguments: '--configuration Release --collect "Code coverage"'

- task: DotNetCoreCLI@2
  displayName: 'Publish Application'
  inputs:
    command: 'publish'
    publishWebProjects: true
    arguments: '--configuration Release --output $(Build.ArtifactStagingDirectory)'
    zipAfterPublish: true

- task: PublishBuildArtifacts@1
  displayName: 'Publish Artifacts'
  inputs:
    pathToPublish: '$(Build.ArtifactStagingDirectory)'
    artifactName: 'drop'
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4. Configure a Release Pipeline (CD)

Navigate to "Releases" and create a new release pipeline. Link it to your build pipeline as a "Create a new release pipeline".

A typical .NET CD pipeline might involve:

  • Artifact: Specifies the output from your CI build.
  • Stages: Define environments like Development, Staging, and Production.
  • Tasks: Within each stage, define tasks to deploy your application. This could involve deploying to Azure App Services, Kubernetes, VMs, etc.
  • Approvals: Configure manual approvals before deploying to sensitive environments like Production.
Diagram of a .NET CD pipeline

For deploying to Azure App Service, you might use the AzureRmWebAppDeployment@4 task.

Best Practices for .NET CI/CD

  • Keep It Fast: Optimize build and test times.
  • Test Thoroughly: Implement unit, integration, and end-to-end tests.
  • Automate Everything: From code commit to deployment.
  • Immutable Infrastructure: Deploy new instances rather than updating existing ones.
  • Monitor Your Deployments: Use application performance monitoring (APM) tools.
  • Secure Your Secrets: Use variable groups or Azure Key Vault for sensitive information.

Next Steps

Explore advanced topics such as:

  • Containerizing your .NET application with Docker.
  • Using infrastructure as code (IaC) with ARM templates or Terraform.
  • Implementing security scanning in your pipeline.
  • Advanced deployment strategies like blue-green deployments or canary releases.
Explore Docker and .NET Learn about IaC