At Microsoft Build 2019, we announced the general availability of Azure Shared Image Gallery, making it easier to manage, share, and globally distribute custom virtual machine (VM) images in Azure.
Shared Image Gallery provides a simple way to share your applications with others in your organization, within or across Azure Active Directory (AD) tenants and regions. This enables you to expedite regional expansion or DevOps processes and simplify your cross-region HA/DR setup.
Shared Image Gallery also supports larger deployments. You can now deploy up to a 1,000 virtual machine instances in a scale set, up from 600 with managed images.
Here is what one of our customers had to say about the feature:
“Shared Image Gallery enables us to build all our VM images from a single Azure DevOps pipeline and to deploy IaaS VMs from these images in any subscription in any tenant in any region, without the added complexity of managing and distributing copies of managed images or VHDs across multiple subscriptions or regions.”
– Stanley Merkx, an Infrastructure Engineer at VIVAT, a Netherlands based insurance company
Shared Image Gallery now supports all Azure public cloud regions as target regions and all generally available Azure public cloud regions, with the exception of South Africa regions as a source region. Check the list of source and target regions.
In the coming months, this feature will also be available in sovereign clouds.
The default quota that is supported on Shared Image Gallery resources include:
- 100 shared image galleries per subscription per region
- 1,000 image definitions per subscription per region
- 10,000 image versions per subscription per region
Users can request for a higher quota based on their requirements. Learn how you can track usage in your subscription.
There is no extra charge for using the Shared Image Gallery service. You will only pay for the following:
- Storage charges for image versions and replicas in each region, source and target
- Network egress charges for replication across regions
Let’s take a quick look at what you can do with Shared Image Gallery.
Manage your images better
We introduced three new Azure Resource Manager resources as part of the feature—gallery, image definition, and image version—which helps you organize images in logical groups. You can also publish multiple versions of your images as and when you update or patch the applications.
Share images across subscriptions and Azure Active Directory tenants
One of the key capabilities that Shared Image Gallery provides is a way to share your images across subscriptions. Since all three newly introduced constructs are Azure Resource Manager resources, you can use Azure role-based access control (RBAC) to share your galleries or image definitions with other users who can then deploy VMs in their subscriptions, even across Azure Active Directory tenants.
A few common scenarios where sharing images across tenants becomes useful are:
- A company acquires another and suddenly the Azure infrastructure is spread across Azure AD tenants.
- A company with multiple subsidiaries that use Azure is likely to have multiple Azure AD tenants.
Learn more about how to share your images across tenants.
Distribute your images globally
We understand that business happens at a global scale and you don’t want your organization to be limited by the platform. Shared Image Gallery provides a way to globally distribute your images based on your organizational needs. You only need to specify the target regions and Shared Image Gallery will replicate your image versions to the regions specified.
Scale your deployments
With Shared Image Gallery, you can now deploy up to a 1,000 VM instances in a VM scale set, an increase from 600 with managed images. We also introduced a concept of image replicas for better deployment performance, reliability, and consistency. You can set a different replica count in each target region based on your regional scale needs. Since each replica is a deep copy of your image, you can scale your deployments linearly with each extra replica versus a managed image.
Learn more about how to use replicas.
Make your images highly available
With the general availability of Shared Image Gallery, you can choose to store your images in zone-redundant storage (ZRS) accounts in regions with Availability Zones. You can also choose to specify storage account type for each of the target regions. Check the regional availability of zone-redundant storage.