1. DevOps Fundamentals

• DevOps = Development + Operations.
• Goal: Automate software delivery, improve collaboration and enhance efficiency.

    1.1 Key Practices:

• CI/CD (Continuous Integration & Continuous Deployment).
• Infrastructure as Code (IaC).
• Monitoring & Logging.
• Security & Compliance.
• Collaboration & Agile Practices.

     1.2  Azure DevOps Services

2. Source Control with Azure Repos

   2.1 Git vs. TFVC (Team Foundation Version Control)

    2.2 Best Practices:

• Use feature branches and pull requests (PRs) for changes.
• Enforce branch policies (e.g., code review, CI checks).
• Use Git Hooks for automation.

   2.3 Common Git Commands

git clone <repo-url>   # Clone a repository
git branch <name>      # Create a new branch
git checkout <name>    # Switch branches
git add .              # Stage changes
git commit -m "message" # Commit changes
git push origin <branch> # Push changes to remote
git pull origin <branch> # Pull latest changes

3. Continuous Integration (CI) with Azure Pipelines

    3.1 CI/CD Pipeline Workflow

• Developer commits code to Azure Repos.
• Azure Pipelines triggers a build (compilation, tests).
• Build artifacts are generated and stored in Azure Artifacts.
• Release pipeline deploys to test/staging/production.

         3.1.1 Azure Pipeline YAML Example

trigger:
  branches:
    include:
      - main
      - dev
pool:
  vmImage: 'ubuntu-latest'
steps:
- task: UseNode@1
  inputs:
    version: '14.x'
- script: npm install
  displayName: 'Install dependencies'
- script: npm test
  displayName: 'Run tests'
- script: npm run build
  displayName: 'Build application'

• Run unit tests and enforce test coverage.
• Use secrets management (Azure Key Vault) instead of hardcoded credentials.
• Implement linting and static code analysis.

4. Continuous Deployment (CD) with Azure Pipelines

4.1 Release Pipeline Stages

• Dev → QA → Staging → Production
• Canary Releases, Blue-Green Deployments, Rolling Deployments

        4.1.1 CD Pipeline Example (YAML)

stages:
- stage: Deploy
  jobs:
  - job: DeployApp
    steps:
    - task: AzureWebApp@1
      inputs:
        azureSubscription: 'MyAzureSubscription'
        appName: 'my-web-app'
        package: '$(Build.ArtifactStagingDirectory)/myapp.zip'

• Automate rollback strategies in case of failure.
• Use feature flags to control feature releases.
• Validate infrastructure configuration before deploying.

5. Infrastructure as Code (IaC) & Configuration Management

    5.1 IaC Tools

• ARM Templates (Azure Resource Manager)
• Terraform
• Bicep
• Ansible / Puppet / Chef

     5.1.1 Terraform Example (Azure VM Deployment)

provider "azurerm" {
  features {}
}
resource "azurerm_resource_group" "rg" {
  name     = "myResourceGroup"
  location = "East US"
}
resource "azurerm_virtual_machine" "vm" {
  name                = "myVM"
  resource_group_name = azurerm_resource_group.rg.name
  location            = azurerm_resource_group.rg.location
  vm_size             = "Standard_B1s"
}

• Use version control for infrastructure configurations.
• Enforce linting (e.g., terraform fmt).
• Implement immutable infrastructure principles.

6. Security & Compliance in DevOps

6.1  Best Practices for Security in DevOps

• Use Azure RBAC (Role-Based Access Control) to restrict permissions.
• Enable MFA for all user logins.
• Use encrypted storage for sensitive data.
• Perform container security scanning (if using Docker).

7. Monitoring & Logging

7.1 Key Azure Monitoring Tools

 Example KQL Query (Log Analytics)

AzureDiagnostics
| where ResourceType == "AzureFirewall"
| summarize count() by bin(TimeGenerated, 1h), ResourceId

• Set up alerts for high CPU/memory usage.
• Monitor failed deployments and rollbacks.
• Implement end-to-end tracing using Application Insights.

8. DevOps Culture & Agile Practices

   8.1 Agile Frameworks in Azure DevOps

• Scrum (Sprints, Backlogs, Retrospectives)
• Kanban (Visualize work in progress)
• SAFe (Scaled Agile Framework) for large teams

      8.1.1 Azure Boards Work Items

   8.2  Best Practices for Agile Development

• Conduct Daily Stand-ups & Sprint Planning.
• Use Kanban boards for work visualization.
• Automate workflow rules in Azure Boards.

9. Cost Optimization in DevOps

9.1 Best Practices for Cost Optimization

• Use Auto-scaling for compute resources.
• Optimize Azure DevTest Labs for testing environments.
• Implement reserved instances for long-term savings.
• Enable budget alerts in Azure Cost Management.

10. Exam Tips & Study Guide

10.1  Key Topics to Focus On:

• CI/CD Pipelines in Azure Pipelines.
• Infrastructure as Code (IaC) with Terraform & ARM.
• Security best practices (Key Vault, RBAC, Policy).
• Monitoring & Logging with Azure Monitor & KQL.
• Git & Azure Repos version control best practices.

10.2  Recommended Learning Paths:

• Microsoft Docs for AZ-400.
• Hands-on Azure DevOps Labs.
• Practice Exam Questions & Mock Tests.

Download Elysium Spark Note