Esri virtual machine images containing ArcGIS for Server, Portal for ArcGIS, ArcGIS Data Store, and ArcGIS Web Adaptor (IIS) are available from the Microsoft Azure Marketplace. Use these images along with ArcGIS Server Cloud Builder for Microsoft Azure and your ArcGIS for Server and Portal for ArcGIS licenses to deploy GIS servers or web GIS sites in the Azure cloud.
Go to Microsoft Azure Marketplace and search for arcgis or esri to find the images. Download them to your Microsoft Azure subscription.
After you access the images, you can customize them if needed.
Next, install ArcGIS Server Cloud Builder for Microsoft Azure and deploy a site.
Microsoft Azure Government
The ArcGIS 10.3.1 image is also available in the Microsoft Azure Government cloud environment.
Microsoft Azure Government is a United States (U.S.) government-community cloud that offers hyperscale compute, storage, networking, and identity management services, with world-class security. A physical and network-isolated instance of Microsoft Azure, operated by screened U.S. personnel, Azure Government enables new forms of cross-agency collaboration and rich cloud service integration. For more information, see http://azure.microsoft.com/en-us/features/gov/.
If you want to deploy on the Azure Government cloud environment and have an Azure Government account, check the U. S. Government account option on the landing page of Cloud Builder before you sign in to your Azure subscription.