Azure DevTest Labs concepts

This article describes key Azure DevTest Labs concepts and definitions. DevTest Labs is a service for easily creating, using, and managing Azure virtual machines (VMs) and other resources.

Labs

A DevTest Labs lab is the infrastructure that encompasses a group of resources such as VMs. DevTest Labs administrators can:

• Add and configure lab users.
• Create ready-made VMs for lab users to claim and use.
• Create and use Azure Resource Manager (ARM) templates to create and configure labs, VMs, and environments.
• Connect artifact and template source control repositories to the lab.
• Let users create and configure their own lab VMs and environments.
• Specify allowed virtual machine (VM) limits, sizes, and configurations.
• Set autoshutdown and autostartup policies.
• Track and manage lab costs.

Roles

Azure role-based access control (RBAC) defines DevTest Labs access and roles. DevTest Labs has three roles that define lab member permissions: Owner, Contributor, and DevTest Labs User.

• Lab Owners can do all lab tasks, including reading or writing to lab resources, setting policies and configurations, adding repositories and base images, and managing users. Only lab Owners can add and manage lab users and roles. For more information about managing user access and roles, see Add lab owners, contributors, and users.

  Lab Owners can also create and assign custom DevTest Labs roles. For more information, see Grant user permissions to specific lab policies.

  A lab Owner must either be an Owner of the Azure subscription the lab is in, or a subscription or lab Owner must grant them the lab Owner role. Subscription Owners can access all subscription resources and users, so they automatically inherit the Owner role for labs in their subscriptions.

• Lab Contributors can do everything that lab Owners can, such as create and configure labs and policies, except they can't assign or manage users and roles. Azure subscription Contributors can create labs, but they aren't Owners of those labs unless they inherit or are granted the lab Owner role.

• DevTest Labs Users can view all lab resources and policies and can create and modify their own VMs and environments, within policy restrictions such as number of VMs per user.

  DevTest Labs Users can't modify lab policies, or view or change any other users' VMs unless the lab or VM owner grants them permission. DevTest Labs Users automatically have Owner permissions on their own VMs.

Policies

Lab policies help control costs and reduce waste. For example, policies can automatically shut down lab VMs based on a defined schedule, or limit the number or sizes of VMs per user or lab. For more information, see Manage lab policies to control costs.

Templates

You can use ARM templates to create and update DevTest Labs labs, environments, VMs, and artifacts.

An Azure Resource Manager template is a JavaScript Object Notation (JSON) file that defines the infrastructure and configuration for your project. The template uses declarative syntax. You describe your intended deployment without writing the sequence of programming commands to create the deployment. For more information about ARM template structure and properties, see Template format.

For more information about using ARM templates in DevTest Labs, see:

• Create labs from ARM templates.
• Create environments from ARM templates.
• Create ARM templates for VMs.

Repositories

Lab users can use templates and artifacts from public and private Git source control repositories to create lab VMs and environments. The DevTest Labs public GitHub repositories offer many ready-to-use artifacts and ARM templates.

Lab administrators can also store custom artifacts and ARM templates in private Git repositories and connect the repositories to their labs. Lab users and automated processes can then use the templates and artifacts. You can add the same repositories to multiple labs in your organization, promoting consistency, reuse, and sharing. For more information, see Add template repositories to labs and Add an artifact repository to a lab.

Virtual machines

You can use templates, artifacts, custom images, and formulas to create and manage DevTest Labs VMs.

Azure VMs are on-demand, scalable computing resources that give you the flexibility of virtualization without having to buy and maintain the physical hardware to run it. For more information about Azure VMs, see Windows virtual machines in Azure.

Base images

A base image is a VM image that can have software and settings preinstalled and configured. Using base images reduces VM creation time and complexity. Lab administrators can choose which base images to make available for their lab users to use for VM creation. For more information, see Create and add virtual machines to a lab.

Artifacts

Artifacts are tools, actions, or software you can add to lab VMs during or after VM creation. For example, artifacts can be:

• Tools to install on the VM, like agents, Fiddler, or Visual Studio.
• Actions to take on the VM, such as cloning a repository or joining a domain.
• Applications that you want to test.

For more information, see Add artifacts to DevTest Labs VMs.

Lab administrators can specify mandatory artifacts to be installed on all lab VMs during VM creation. For more information, see Specify mandatory artifacts for DevTest Labs VMs.

Claimable VMs

Lab administrators can prepare VMs with specific configurations and save them to a shared pool, where they appear in the lab's Claimable virtual machines list. Any lab user can claim a VM from the claimable pool when they need a VM with that configuration.

After a lab user claims a VM, the VM moves to that user's My virtual machines list, and the user becomes the owner of the VM. The VM is no longer claimable or configurable by other users. For more information, see Create and manage claimable VMs.

Custom images and formulas

DevTest Labs custom images and formulas are mechanisms for fast VM creation and provisioning.

• A custom image is a VM image created from an existing VM or virtual hard disk (VHD), which can have software and other artifacts installed. Lab users can create identical VMs from the custom image. For more information, see Create a custom image from a VM.

• A formula is a list of default property values for creating a lab VM, such as base image, VM size, virtual network, and artifacts. When you create a VM from a formula, you can use the default values as-is or modify them. For more information, see Manage Azure DevTest Labs formulas.

For more information about custom images and formulas, see Compare custom images and formulas.

Environments

A DevTest Labs environment is a collection of Azure platform-as-a-service (PaaS) resources, such as an Azure Web App or a SharePoint farm, that an ARM template defines. Lab administrators can add public or privately created environment templates to labs, and lab users can use them to quickly create environments. For more information, see Use ARM templates to create DevTest Labs environments.

Get started with Azure DevTest Labs

New to Azure? Create a free Azure account.

Already on Azure? Create your first lab and get started with Azure DevTest Labs in minutes.