Azure DevOps is a suite of development tools provided by Microsoft that offers integrated services for version control, project management, build automation, continuous integration, and continuous delivery (CI/CD). It is a powerful platform that brings together developers, project managers, and other contributors to create high-quality software efficiently.

Azure DevOps Services offer two essential components for software development:

1. Code Repositories, which enable teams to store and manage their source code with robust version control systems like Git or Team Foundation Version Control (TFVC).
2. CI/CD Pipelines, which automate the process of building, testing, and deploying applications, ensuring faster release cycles and higher-quality software.

In this knowledge-based article, we will explore the key features and benefits of Azure DevOps code repositories and CI/CD pipelines, along with practical steps for setting up and managing them for efficient DevOps workflows.

Azure Repos Code Repositories in Azure DevOps

What is Azure Repos?

Azure Repos is a service in Azure DevOps that provides version control for your code. It supports two types of version control systems:

• Git: A distributed version control system that allows developers to work on branches, commit changes locally, and merge branches to the main repository. It is the most commonly used system for modern development.
• Team Foundation Version Control (TFVC): A centralized version control system that works with a server-based repository.

With Azure Repos, teams can collaborate on code, manage multiple branches, and track changes over time. The system ensures that code can be shared, reviewed, and tested collaboratively before deployment.

Benefits of Using Azure Repos

• Collaboration: Multiple team members can work on the same project simultaneously by creating separate branches. These branches can be merged into the main codebase after a thorough review.
• Code Review Process: Azure Repos supports pull requests and code reviews, allowing developers to review, comment, and approve changes before merging.
• Branching Strategy: It allows you to implement various branching strategies like feature branches, release branches, and hotfixes.
• Integration with Work Items: Code commits can be linked to work items, giving visibility into which features or bugs are being addressed in a particular commit.
• Audit Trails: The history of all changes is maintained, allowing you to track changes and revert if needed.

Setting Up an Azure Repo

To set up an Azure Repo, follow these steps:

1. Create a Project:

   • In the Azure DevOps portal, click on New Project and enter a name for your project. This project will house your code repositories, pipelines, and other Azure DevOps services.

2. Create a Repository:

   • Once the project is created, go to the Repos section.
   • You can choose to create a new Git repository or import an existing repository from GitHub, Bitbucket, or other Git services.

3. Clone the Repository Locally:

   • After creating the repository, clone it to your local machine using a Git client. Use the provided Git URL to clone the repository.

4. Commit and Push Code:

   • Make changes to the codebase locally, then commit and push the code to the remote repository in Azure Repos.

Branching and Pull Requests

Branching Strategy

A well-defined branching strategy is critical for managing code changes in a collaborative environment. Common strategies include:

• Main/Trunk-Based Development: All changes are committed to the main branch, and testing is done on feature branches.
• GitFlow: A more complex model with dedicated branches for features, releases, and hotfixes.

Creating a Pull Request

After creating a feature branch and committing changes, you will need to submit a Pull Request to merge the code into the main branch:

• In the Azure Repos portal, navigate to the Pull Requests section.
• Select your source branch (e.g., feature/new-feature) and target branch (e.g., main).
• Submit the pull request, which can then be reviewed and approved by team members.

Azure Pipelines CI/CD in Azure DevOps

Azure Pipelines is a fully managed CI/CD service in Azure DevOps that enables you to automate the build, test, and deployment process for your applications. It supports multiple programming languages, frameworks, and deployment targets, including Azure, AWS, on-premises servers, and Kubernetes.

What is Continuous Integration (CI)?

Continuous Integration (CI) is the practice of automatically building and testing code every time a developer pushes a change to the version control system. CI helps detect bugs and integration issues early, reducing the risk of them reaching production.

What is Continuous Delivery (CD)?

Continuous Delivery (CD) extends CI by automating the deployment of applications to various environments, such as development, staging, and production. CD ensures that applications are always ready for release, and deployments are automated and consistent.

Benefits of Azure Pipelines for CI/CD

• Automation: Automate the entire process of building, testing, and deploying code, reducing manual effort.
• Parallel Jobs: Run multiple jobs in parallel, speeding up the build and test process.
• Integration with Azure Services: Seamlessly deploy applications to Azure services such as Virtual Machines (VMs), Azure Kubernetes Service (AKS), and App Service.
• Multi-Platform Support: Build and deploy applications across Windows, Linux, and macOS environments.
• Pipeline Templates: Reuse and share pipeline configurations across different projects using templates.
• Support for Containers: Build and deploy Docker containers using Azure Pipelines.

Setting Up a CI/CD Pipeline in Azure Pipelines

Setting up a CI/CD pipeline involves several key steps:

Create a New Pipeline

• Navigate to the Pipelines section in Azure DevOps and click on New Pipeline.
• Select your code repository (Azure Repos Git, GitHub, Bitbucket, etc.).

Define Your Pipeline in YAML

Azure Pipelines supports pipelines as code, meaning you can define your CI/CD pipeline using a YAML file (azure-pipelines.yml). The file specifies the steps for building, testing, and deploying the application.

Configure Build Triggers

Set up triggers to automatically start the build process when code is pushed to the repository. You can configure:

• Continuous Integration (CI) Triggers: Automatically trigger a build when changes are pushed to specific branches.
• Scheduled Builds: Run builds at specific times, such as nightly or weekly builds.

Add Stages for Deployment (CD)

After the build is completed successfully, the pipeline can move to the deployment stage. Azure Pipelines allows you to deploy to various environments (development, staging, production), ensuring that applications are tested in each environment before going live.

Approval Gates

Add manual approval gates to ensure that certain deployments require approval before they are pushed to production.

Best Practices for Azure Repos and Pipelines

Implementing Branch Policies

Branch policies help ensure that code is reviewed and tested before it is merged into important branches like main or release. Policies you can implement include:

• Require a minimum number of reviewers for pull requests.
• Enforce passing status checks (builds/tests must pass before the merge).
• Require linked work items, ensuring that every code change is associated with a tracked work item.

Use Secrets Securely in Pipelines

When deploying applications, you might need to use sensitive information like passwords, API keys, or connection strings. Azure Pipelines offers secure methods to manage secrets:

• Azure Key Vault: Store sensitive data in Azure Key Vault and reference them securely in pipelines.
• Pipeline Secrets: Store secrets in the pipeline’s variable groups with encryption.

Monitor Pipelines and Improve Efficiency

Monitor the performance and success rates of your pipelines to ensure efficiency:

• Pipeline Analytics: Azure DevOps provides analytics on build and release times, failure rates, and trends.
• Optimize Parallel Jobs: Use parallel jobs to speed up the pipeline by running different tasks concurrently.