Microsoft Certified: DevOps Engineer ExpertDesign and implement source controlEasy
An organization is moving from an on-premises build server to Azure DevOps build agents. They have several legacy applications that require specific, outdated compiler versions and custom command-line tools that are not available on Microsoft-hosted agents. Which type of build agent should they implement to support these legacy applications?
- AMicrosoft-hosted agents with custom scripts
- BSelf-hosted agents configured with required software
- CContainerized agents running on Azure Container Instances
- DScale set agents within an Azure Virtual Machine Scale Set
Show answer & explanationAnswer & explanation
Correct answer: B. Self-hosted agents configured with required software
Self-hosted agents provide the flexibility to install any necessary software, tools, and dependencies, including specific compiler versions or custom command-line tools, directly onto the agent machine. This makes them ideal for building legacy applications with unique requirements.
Why the other options are wrong
- A. Microsoft-hosted agents have a predefined set of software and cannot be customized with specific, outdated compiler versions or custom tools.
- C. Containerized agents can be customized, but the problem states 'specific, outdated compiler versions and custom command-line tools' which might be easier to manage on a full VM (self-hosted agent) rather than trying to containerize potentially complex, interdependent legacy tools.
- D. Scale set agents are a type of self-hosted agent managed by a scale set, but the core requirement is the ability to install custom software, which is a feature of self-hosted agents in general.
Self-Hosted Azure DevOps Agents
Build agents that you set up and manage on your own infrastructure (on-premises or cloud VMs), providing full control over the installed software and environment.
- Provides full control over installed software and dependencies.
- Required for specific hardware, custom tools, or outdated software not on Microsoft-hosted agents.
- Requires manual management of agent updates and maintenance.
Memory trick: Think of agents as workers: Microsoft-hosted are generalists, self-hosted are specialists with custom tools, and scale sets are a fleet of specialists.