Self-hosted Windows agents

TFS 2017 | TFS 2015

To build and deploy Windows, Azure, and other Visual Studio solutions you'll need at least one Windows agent. Windows agents can also build Java and Android apps.

Before you begin:

• If your code is in Azure Pipelines and a Microsoft-hosted agent meets your needs, you can skip setting up a self-hosted Windows agent.
• If your code is in an on-premises Team Foundation Server (TFS) 2015 server, see Deploy an agent on Windows for on-premises TFS 2015.
• Otherwise, you've come to the right place to set up an agent on Windows. Continue to the next section.

Learn about agents

If you already know what an agent is and how it works, feel free to jump right in to the following sections. But if you'd like some more background about what they do and how they work, see Azure Pipelines agents.

Check prerequisites

Make sure your machine has these prerequisites:

• Windows 7, 8.1, or 10 (if using a client OS)
• Windows 2008 R2 SP1 or higher (if using a server OS)
• PowerShell 3.0 or higher
• .NET Framework 4.6.2 or higher

Important

Starting December 2019, the minimum required .NET version for build agents is 4.6.2 or higher.

Recommended:

• Visual Studio build tools (2015 or higher)

If you're building from a Subversion repo, you must install the Subversion client on the machine.

You should run agent setup manually the first time. After you get a feel for how agents work, or if you want to automate setting up many agents, consider using unattended config.

Hardware specs

The hardware specs for your agents will vary with your needs, team size, etc. It's not possible to make a general recommendation that will apply to everyone. As a point of reference, the Azure DevOps team builds the hosted agents code using pipelines that utilize hosted agents. On the other hand, the bulk of the Azure DevOps code is built by 24-core server class machines running 4 self-hosted agents apiece.

Prepare permissions

Information security for self-hosted agents

The user configuring the agent needs pool admin permissions, but the user running the agent does not.

The folders controlled by the agent should be restricted to as few users as possible and they contain secrets that could be decrypted or exfiltrated.

The ADO pipelines agent is a software product designed to execute code it downloads from external sources. It inherently could be a target for Remote Code Execution (RCE) attacks.

Therefore, it is important to consider the threat model surrounding each individual usage of Pipelines Agents to perform work, and decide what are the minimum permissions could be granted to the user running the agent, to the machine where the agent runs, to the users who have write access to the Pipeline definition, the git repos where the yaml is stored, or the group of users who control access to the pool for new pipelines.

It is a best practice to have the identity running the agent be different from the identity with permissions to connect the agent to the pool. The user generating the credentials (and other agent-related files) is different than the user that needs to read them. Therefore, it is safer to carefully consider access granted to the agent machine itself, and the agent folders which contain sensitive files, such as logs and artifacts.

It makes sense to grant access to the agent folder only for DevOps administrators and the user identity running the agent process. Administrators may need to investigate the file system to understand build failures or get log files to be able to report Azure DevOps failures.

Decide which user you'll use

As a one-time step, you must register the agent. Someone with permission to administer the agent queue must complete these steps. The agent will not use this person's credentials in everyday operation, but they're required to complete registration. Learn more about how agents communicate.

Authenticate with a personal access token (PAT)

1. Sign in with the user account you plan to use in your Team Foundation Server web portal (https://{your-server}:8080/tfs/).

2. From your home page, open your profile. Go to your security details.

   

3. Create a personal access token.

   

4. For the scope select Agent Pools (read, manage) and make sure all the other boxes are cleared. If it's a deployment group agent, for the scope select Deployment group (read, manage) and make sure all the other boxes are cleared.

   Select Show all scopes at the bottom of the Create a new personal access token window window to see the complete list of scopes.

5. Copy the token. You'll use this token when you configure the agent.

Authenticate as a Windows user (TFS 2015 and TFS 2017)

As an alternative, on TFS 2017, you can use either a domain user or a local Windows user on each of your TFS application tiers.

Confirm the user has permission

Make sure the user account that you're going to use has permission to register the agent.

Is the user an Azure DevOps organization owner or TFS or Azure DevOps Server administrator? Stop here, you have permission.

Otherwise:

1. Open a browser and navigate to the Agent pools tab for your Azure Pipelines organization or Azure DevOps Server or TFS server:

   1. Navigate to your project and choose Settings (gear icon) > Agent Queues.

      

   2. Choose Manage pools.

      

2. Select the pool on the right side of the page and then click Security.

3. If the user account you're going to use is not shown, then get an administrator to add it. The administrator can be an agent pool administrator, an Azure DevOps organization owner, or a TFS or Azure DevOps Server administrator.

   If it's a deployment group agent, the administrator can be an deployment group administrator, an Azure DevOps organization owner, or a TFS or Azure DevOps Server administrator.

   You can add a user to the deployment group administrator role in the Security tab on the Deployment Groups page in Azure Pipelines.

Note

If you see a message like this: Sorry, we couldn't add the identity. Please try a different identity., you probably followed the above steps for an organization owner or TFS or Azure DevOps Server administrator. You don't need to do anything; you already have permission to administer the agent queue.

Download and configure the agent

1. Log on to the machine using the account for which you've prepared permissions as explained above.

2. In your web browser, sign in to TFS, and navigate to the Agent pools tab:

   1. Navigate to your project and choose Settings (gear icon) > Agent Queues.

      

   2. Choose Manage pools.

      

3. Click Download agent.

4. On the Get agent dialog box, click Windows.

5. Click the Download button.

6. Follow the instructions on the page to download the agent.

7. Unpack the agent into the directory of your choice. Make sure that the path to the directory contains no spaces because tools and scripts don't always properly escape spaces. A recommended folder is C:\agents. Extracting in the download folder or other user folders may cause permission issues. Then run config.cmd.

Important

We strongly recommend you configure the agent from an elevated PowerShell window. If you want to configure as a service, this is required.

Important

For security reasons we strongly recommend making sure the agents folder (C:\agents) is only editable by admins.

Note

Please avoid using mintty based shells, such as git-bash, for agent configuration. Mintty is not fully compatible with native Input/Output Windows API (here is some info about it) and we couldn't guarantee correct work of setup script in this case.

Server URL and authentication

When setup asks for your server URL, for TFS, answer https://{your_server}/tfs.

Important

Make sure your server is configured to support the authentication method you want to use.

When you configure your agent to connect to TFS, you've got the following options:

• Alternate Connect to TFS using Basic authentication. After you select Alternate you'll be prompted for your credentials.

• Negotiate Connect to TFS as a user other than the signed-in user via a Windows authentication scheme such as NTLM or Kerberos. After you select Negotiate you'll be prompted for credentials.

• Integrated (Default) Connect a Windows agent to TFS using the credentials of the signed-in user via a Windows authentication scheme such as NTLM or Kerberos. You won't be prompted for credentials after you choose this method.

• PAT Supported only on Azure Pipelines and TFS 2017 and newer. After you choose PAT, paste the PAT token you created into the command prompt window. Use a personal access token (PAT) if your TFS instance and the agent machine are not in a trusted domain. PAT authentication is handled by your TFS instance instead of the domain controller.

Note

When using PAT as the authentication method, the PAT token is used only for the initial configuration of the agent. If the PAT needs to be regenerated, no further changes are needed to the agent.

Learn more at Communication with Azure Pipelines or TFS.

Choose interactive or service mode

For guidance on whether to run the agent in interactive mode or as a service, see Agents: Interactive vs. service.

If you choose to run as a service (which we recommend), the username you run as should be 20 characters or fewer.

Run the agent

Run interactively

If you configured the agent to run interactively, to run it:

.\run.cmd

To restart the agent, press Ctrl+C to stop the agent and then run run.cmd to restart it.

Run once

For agents configured to run interactively, you can choose to have the agent accept only one job. To run in this configuration:

.\run.cmd --once

Agents in this mode will accept only one job and then spin down gracefully (useful for running in Docker on a service like Azure Container Instances).

Run as a service

If you configured the agent to run as a service, it starts automatically. You can view and control the agent running status from the services snap-in. Run services.msc and look for one of:

• "Azure Pipelines Agent (name of your agent)".
• "VSTS Agent (name of your agent)".
• "vstsagent.(organization name).(name of your agent)".

To restart the agent, right-click the entry and choose Restart.

Note

If you need to change the agent's logon account, don't do it from the Services snap-in. Instead, see the information below to re-configure the agent.

To use your agent, run a job using the agent's pool. If you didn't choose a different pool, your agent will be in the Default pool.

Replace an agent

To replace an agent, follow the Download and configure the agent steps again.

When you configure an agent using the same name as an agent that already exists, you're asked if you want to replace the existing agent. If you answer Y, then make sure you remove the agent (see below) that you're replacing. Otherwise, after a few minutes of conflicts, one of the agents will shut down.

Remove and re-configure an agent

To remove the agent:

.\config remove

After you've removed the agent, you can configure it again.

Unattended config

The agent can be set up from a script with no human intervention. You must pass --unattended and the answers to all questions.

To configure an agent, it must know the URL to your organization or collection and credentials of someone authorized to set up agents. All other responses are optional. Any command-line parameter can be specified using an environment variable instead: put its name in upper case and prepend VSTS_AGENT_INPUT_. For example, VSTS_AGENT_INPUT_PASSWORD instead of specifying --password.

Required options

• --unattended - agent setup will not prompt for information, and all settings must be provided on the command line
• --url <url> - URL of the server. For example: https://dev.azure.com/myorganization or http://my-azure-devops-server:8080/tfs
• --auth <type> - authentication type. Valid values are:
  • pat (Personal access token)
  • negotiate (Kerberos or NTLM)
  • alt (Basic authentication)
  • integrated (Windows default credentials)

Authentication options

• If you chose --auth pat:
  • --token <token> - specifies your personal access token
• If you chose --auth negotiate or --auth alt:
  • --userName <userName> - specifies a Windows username in the format domain\userName or userName@domain.com
  • --password <password> - specifies a password

Pool and agent names

• --pool <pool> - pool name for the agent to join
• --agent <agent> - agent name
• --replace - replace the agent in a pool. If another agent is listening by the same name, it will start failing with a conflict

Agent setup

• --work <workDirectory> - work directory where job data is stored. Defaults to _work under the root of the agent directory. The work directory is owned by a given agent and should not be shared between multiple agents.
• --acceptTeeEula - accept the Team Explorer Everywhere End User License Agreement (macOS and Linux only)
• --disableloguploads - don't stream or send console log output to the server. Instead, you may retrieve them from the agent host's filesystem after the job completes.

Windows-only startup

• --runAsService - configure the agent to run as a Windows service (requires administrator permission)
• --runAsAutoLogon - configure auto-logon and run the agent on startup (requires administrator permission)
• --windowsLogonAccount <account> - used with --runAsService or --runAsAutoLogon to specify the Windows user name in the format domain\userName or userName@domain.com
• --windowsLogonPassword <password> - used with --runAsService or --runAsAutoLogon to specify Windows logon password
• --overwriteAutoLogon - used with --runAsAutoLogon to overwrite the existing auto logon on the machine
• --noRestart - used with --runAsAutoLogon to stop the host from restarting after agent configuration completes

Deployment group only

• --deploymentGroup - configure the agent as a deployment group agent
• --deploymentGroupName <name> - used with --deploymentGroup to specify the deployment group for the agent to join
• --projectName <name> - used with --deploymentGroup to set the project name
• --addDeploymentGroupTags - used with --deploymentGroup to indicate that deployment group tags should be added
• --deploymentGroupTags <tags> - used with --addDeploymentGroupTags to specify the comma separated list of tags for the deployment group agent - for example "web, db"

Environments only

• --addvirtualmachineresourcetags - used to indicate that environment resource tags should be added
• --virtualmachineresourcetags <tags> - used with --addvirtualmachineresourcetags to specify the comma separated list of tags for the environment resource agent - for example "web, db"

.\config --help always lists the latest required and optional responses.

Diagnostics

If you're having trouble with your self-hosted agent, you can try running diagnostics. After configuring the agent:

.\run --diagnostics

This will run through a diagnostic suite that may help you troubleshoot the problem. The diagnostics feature is available starting with agent version 2.165.0.

Help on other options

To learn about other options:

.\config --help

The help provides information on authentication alternatives and unattended configuration.

Capabilities

Your agent's capabilities are cataloged and advertised in the pool so that only the builds and releases it can handle are assigned to it. See Build and release agent capabilities.

In many cases, after you deploy an agent, you'll need to install software or utilities. Generally you should install on your agents whatever software and tools you use on your development machine.

For example, if your build includes the npm task, then the build won't run unless there's a build agent in the pool that has npm installed.

Important

Capabilities include all environment variables and the values that are set when the agent runs. If any of these values change while the agent is running, the agent must be restarted to pick up the new values. After you install new software on an agent, you must restart the agent for the new capability to show up in the pool, so that the build can run.

If you want to exclude environment variables as capabilities, you can designate them by setting an environment variable VSO_AGENT_IGNORE with a comma-delimited list of variables to ignore.

FAQ

How do I make sure I have the latest v2 agent version?

1. Navigate to the Agent pools tab:

   1. Navigate to your project and choose Settings (gear icon) > Agent Queues.

      

   2. Choose Manage pools.

      

2. Click the pool that contains the agent.

3. Make sure the agent is enabled.

4. Navigate to the capabilities tab:

   Select the desired agent, and choose the Capabilities tab.

   

5. Look for the Agent.Version capability. You can check this value against the latest published agent version. See Azure Pipelines Agent and check the page for the highest version number listed.

6. Each agent automatically updates itself when it runs a task that requires a newer version of the agent. If you want to manually update some agents, right-click the pool, and select Update all agents.

Can I update my v2 agents that are part of an Azure DevOps Server pool?

Yes. Beginning with Azure DevOps Server 2019, you can configure your server to look for the agent package files on a local disk. This configuration will override the default version that came with the server at the time of its release. This scenario also applies when the server doesn't have access to the internet.

1. From a computer with Internet access, download the latest version of the agent package files (in .zip or .tar.gz form) from the Azure Pipelines Agent GitHub Releases page.

2. Transfer the downloaded package files to each Azure DevOps Server Application Tier by using a method of your choice (such as USB drive, Network transfer, and so on). Place the agent files under the %ProgramData%\Microsoft\Azure DevOps\Agents folder.

3. You're all set! Your Azure DevOps Server will now use the local files whenever the agents are updated. Each agent automatically updates itself when it runs a task that requires a newer version of the agent. But if you want to manually update some agents, right-click the pool, and then choose Update all agents.

What version of the agent runs with TFS 2017?

TFS version	Minimum agent version
2017 RTM	2.105.7
2017.3	2.112.0

How do I run the agent with self-signed certificate?

Run the agent with self-signed certificate

How do I run the agent behind a web proxy?

Run the agent behind a web proxy

How do I restart the agent

If you are running the agent interactively, see the restart instructions in Run interactively. If you are running the agent as a service, restart the agent by following the steps in Run as a service.