What is Azure VM Image Builder?
Azure VM Image Builder is a managed service that automates the creation and maintenance of custom virtual machine images. Instead of manually configuring VMs and capturing them as images, you define an image template that specifies the base image, customization steps, and distribution targets.
The service handles the build process: spinning up a temporary VM, running your customization scripts, capturing the result, and distributing it to Azure Compute Gallery or managed image repositories.
Core Features
- Template-based: Define images as code using JSON or Bicep
- Built-in customizers: Run PowerShell, shell scripts, or file copies
- Windows Update integration: Automatically apply latest patches during builds
- Gallery distribution: Publish to Azure Compute Gallery for versioning and sharing
- Triggers: Rebuild images on schedule or when base images are updated
Typical Use Cases
Image Builder is essential for organizations that need consistent, up-to-date VM images across environments. Common scenarios include creating hardened base images with security configurations, building developer workstation images with pre-installed tools, and maintaining patched images for production VMs.
Benefits
- Infrastructure as code approach for image management
- No need to maintain build VMs
- Consistent images across subscriptions and regions
- Integration with Azure DevOps and GitHub Actions
Frequently Asked Questions
What operating systems are supported?
Image Builder supports Windows Server, Windows 10/11, and major Linux distributions including Ubuntu, RHEL, CentOS, and SUSE. You can start from Azure Marketplace images or your own base images.
How does versioning work?
When distributing to Azure Compute Gallery, each build creates a new image version. You can define retention policies and replicate versions across regions for high availability.
Can I use Packer with Image Builder?
Image Builder uses an Azure-native approach, but if you have existing Packer templates, you can continue using Packer with Azure. Image Builder offers tighter Azure integration and managed infrastructure.
How long do builds take?
Build time depends on customization complexity. A simple image with Windows Update might take 30 to 60 minutes. Complex builds with many software installations can take several hours.
Integration with innFactory
As a Microsoft Solutions Partner, innFactory helps you implement Azure VM Image Builder: template design, CI/CD pipeline integration, and image management strategy.
