Setting up and Running Additional Build Agents

This page covers:

Before you can start customizing projects and creating build configurations, you need to configure build agents.

Installing Additional Build Agents

Before the installation, please review Known Issues#Conflicting Software section.

Necessary OS and environment permissions

Please note that in order to run a TeamCity build agent, user account that is running the agent should have the privileges described below.

Network

• Agent should be able to open HTTP connections to the server (to the same URL as server web UI)
• Server should be able to open HTTP connections to the agent. The port is determined by "ownPort" property of buildAgent.properties file (9090 by default) and the following hosts are tried:
  • host specified in the "ownAddress" property of buildAgent.properties file (if any)
  • source host of the request received by the server when agent establishes connection to the server
  • address of the network interfaces on the agent machine

If the agent is behind NAT and cannot be accessed by any of addresses of agent machine network interfaces, please specify ownAddress in the agent config.

Common

• agent process (java) should be able to open outbound HTTP connections to the server address (the same address you use in the browser to view TeamCity UI) and accept inbound HTTP connections from the server to the port specified as "ownPort" property in "<TeamCity agent home>/conf/buildAgent.properties" file (9090 by default). Please ensure that any firewalls installed on agent, server machine or in the network and network configuration comply with these requirements.
• have full permissions (read/write/delete) to the following directories: <agent home> (necessary for automatic agent upgrade), <agent work>, and <agent temp>.
• launch processes (to run builds).

Windows

• Log on as a service (to run as Windows service)
• Start/Stop service (to run as Windows service, necessary for agent upgrade to work, see also Microsoft KB article)
• Debug programs (for take process dump functionality to work)
• Reboot the machine (for agent reboot functionality to work)

For granting necessary permissions for unprivileged users, see Microsoft SubInACL utility. For example, to grant Start/Stop rights you might need to execute subinacl.exe /service browser /grant=<login name>=PTO command.

Linux

• user should be able to run shutdown command (for agent machine reboot functionality and machine shutdown functionality when running in Amazon EC2)

Build-related Permissions
The build process is launched by TeamCity agent and thus shares the environment and is executed under the same OS user that TeamCity agent runs under. Please ensure that TeamCity agent is configured accordingly.
See Known Issues for related Windows Service Limitations.

Server-Agent Data Transfers

During TeamCity operations, both server establishes connections to the agents and agents establish connections to the server.

Please note that by default, these connections are not secured and thus are exposing possibly sensitive data to any third party that can listen to the traffic between the server and the agents. Moreover, since the agent and server can send "commands" to each other an attacker that can send HTTP requests and capture responses can in theory trick agent into executing arbitrary command and perform other actions with a security impact.

It is recommended to deploy agents and the server into a secure environment and use plain HTTP for agents-to-server communications as this reduces transfer overhead.

It is possible to setup a server to be available via HTTPS protocol, so all the data traveling through the connections established from an agent to the server (incl. download of build's sources, artifacts of builds, build progress messages and build log) can be secured. See Using HTTPS to access TeamCity server for configuration details.

However, the data that is transferred via the connections established by the server to agents (build configuration settings (all the settings configured on the web UI including VCS root data) is passed via unsecured HTTP connection. For the time being TeamCity does not provide internal means to secure this data transfers (see/vote for TW-5815). If you want to secure the data you need to establish appropriate network security configurations like VPN connections between agent and server machines.

Installing Procedure

You can install build agents using any of the following installation options available:

• Via Java Web Start
• Using MS Windows installer
• Download zip file and install manually

After installation, please configure the agent specifying it's name and address of TeamCity server in it's conf/buildAgent.properties file.
Then start the agent.

When the newly installed agent connects to the server for the first time, it appears on the Unauthorized agents tab under Agents, where administrators can authorize it. This will connect the agent to the server for the first time.

If the agent does not seem to run correctly, please check the agent logs.

Installing via Java Web Start

1. Make sure JDK 1.6+ is properly installed on the computer.
2. On the agent computer, set up the JAVA_HOME environment variable to point to the JDK 1.6+ installation directory.
3. Navigate to the Agents tab in the TeamCity web UI.
4. Click the "Install Build Agents" link and then click "Via Java Web Start".
5. Follow the instructions.
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   You can install the build agent Windows service during the installation process or manually.

Installing via a MS Windows installer

1. Navigate to the Agents tab in the TeamCity web UI.
2. Click the "Install Build Agents" link and then click MS Windows Installer link to download the installer.
3. Run the agentInstaller.exe Windows Installer and follow the installation instructions.
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   Please ensure the user under whom the agent service is running has appropriate permissions

Installing via ZIP File

1. In TeamCity Web UI, navigate to the Agents tab
2. Click the Install Build Agents link and then click download zip file
3. Unzip the downloaded file into the desired directory.
4. Make sure that you have a JDK or JRE 1.6+ installed (You will need JDK (not JRE) for some build runners like IntelliJ IDEA, Java Inspections and Duplicates). Please ensure that the JRE_HOME or JAVA_HOME environment variables are set (pointing to the installed JRE or JDK directory respectively) for the shell in which the agent will be started.
5. Navigate to the <installation path>\conf directory, locate the file called buildAgent.dist.properties and rename it to buildAgent.properties.
6. Edit the buildAgent.properties file to specify the TeamCity server URL and the name of the agent. Please refer to Build Agent Configuration section for more details on agent configuration
7. Under Linux, you may need to give execution permissions to the bin/agent.sh shell script.
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   On Windows you may also want to install the build agent windows service instead of manual agent startup.

Installing via Agent Push

TeamCity provide functionality that allows to install a build agent to a remote host. Currently supported combinations of server host platform and targets for build agents are:

• from Unix based TeamCity server build agents can be installed to Unix hosts only(via SSH).
• from Windows based TeamCity server build agents can be installed to Unix (via SSH) or Windows(via psexec) hosts.

There are several requirements for the remote host that should be met:

Installation Procedure

1. In the TeamCity Server web UI navigate to Agents | Agent Push tab, and click Install Agent....
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   Note, that if you are going to use same settings for several target hosts, you can create a preset with these settings, and use it next time when installing an agent to another remote host.

2. In the Install agent dialog, if you don't yet have any presets saved, select "Use custom settings", specify target host platform and configure corresponding settings.
3. You may need to download Sysinternals psexec.exe, in which case you will see corresponding warning and a link to Administration | Server Configuration | Tools tab where you can download it.

Starting the Build Agent

To start the agent manually, run the following script:

• for Windows: <installation path>\bin\agent.bat start
• for Linux and MacOS X: <installation path>\bin\agent.sh start
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  If you're running build agent on MacOS X and you're going to run Inspection builds, you may need to use the StartupItemContext utility:

To configure agent to be started automatically, see corresponding sections:
Windows
Mac OS X
Linux: configure daemon process with agent.sh start command to start it and agent.sh stop command to stop it.

Stopping the Build Agent

To stop the agent manually, run the <Agent home>\agent script with a stop parameter.

Use stop to request stopping after current build finished.
Use stop force to request immediate stop (if a build is running on the agent, it will be stopped abruptly (canceled))
Under Linux, you have one more option to use: stop kill to kill the agent process.

If the agent runs with a console attached, you may also press Ctrl+C in the console to stop the agent (if a build is running it will be canceled).

Automatic Agent Start under Windows

To run agent automatically on machine boot under Windows you can either setup agent to be run as Windows service or use another way of automatic process start.
Using Windows service approach is the easiest way, but Windows applies some constraints to the processes run in this way.
TeamCity agent can work OK under Windows service (provided all the requirements are met), but is often not the case for the build processes that you will configure to be run on the agent.

That is why it is advised to run TeamCity agent as use Windows service only if all the build scripts support this.
Otherwise, it is advices to use alternative ways to start TeamCity agent automatically.
One of the ways is to configure automatic user logon on Windows start and then configure TeamCity agent start (via agent.bat start) on user logon.

Build Agent as a Windows Service

In Windows, you may want to use the build agent Windows service to allow the build agent to run without any user logged on.
If you use Windows agent installer you have an option to install the service in the installation wizard.

The following instruction can be used to install the service manually. This procedure should also be performed to install second and following agents on the same machine as Windows services

To install the service:

1. Make sure there is no TeamCity Build Agent Service <build number> service already installed, if installed, uninstall the agent.
2. Check wrapper.java.command property in <agent home>\launcher\conf\wrapper.conf file to contain valid path to Java executable in the JDK installation directory. You can use wrapper.java.command=../jre/bin/java for agent installed with Windows distribution.
3. Run the <agent home>/bin/service.install.bat file.

To start the service:

• Run <agent home>/bin/service.start.bat
  (or use Windows standard Services applet)

To stop the service:

• Run <agent home>/bin/service.stop.bat
  (or use Windows standard Services applet)

You can also use Windows net.exe utility to manage the service once it is installed.
For example (assuming the default service name):

The file <agent home>\launcher\conf\wrapper.conf can also be used to alter agent JVM parameters.

Using LaunchDaemons Startup Files on MacOSx

For MacOSx, TeamCity provides ability to load a build agent automatically at the system startup using LaunchDaemons plist file.

To use LaunchDaemons plist file:

1. Install build agent on Mac either via buildAgent.zip or via Java web-start
2. Prepare conf/buildAgent.properties file
3. Fix launcher permissions, if needed: chmod +x buildAgent/launcher/bin/*
4. Load build agent to LaunchDaemon via command:
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   You have to wait several minutes for the build agent to auto-upgrade from the TeamCity server.

5. Copy buildAgent/bin/jetbrains.teamcity.BuildAgent.plist to /Library/LaunchDaemons directory for automatic startup (you may need to create this directory, if it doesn't exists). This will result in the build agent starting under root. To start agent under a different user, use ~/Library/LaunchAgents.
6. To stop build agent, run the following command:

If you need to configure TeamCity agent environment you can change <TeamCity Agent Home>/launcher/conf/wrapper.conf (JSW configuration). For example, to make the agent see Mono installed using MacPorts on Mac OS X agent you will need to add the following line:

Configuring Java

TeamCity Agent is a Java application and it requires JDK version 1.5 or later to work (JDK 1.6 is recommended as further TeamCity versions will require 1.6 for the agent).
.exe TeamCity distribution comes with appropriate Java bundled.
For .zip agent installation you need to have Java installed (available via PATH) or available in one of the following places:

• <Agent home>/jre
• in the directory pointed to by JAVA_HOME or JRE_HOME environment variables.

Upgrading Java on Agents

If a build agent uses a Java version older than it is required by agent version, you will see the corresponding warning at the agent's page. This may happen when upgrading to a newer TeamCity version, which doesn't support an old Java version anymore. To update Java on agents you can do one of the following:

• Since build agent .exe installation comes bundled with required Java, you can just run agent .exe (obtained from TeamCity server | Agents page) on an agent machine and it will update the Java installation that agent uses.
• Install required Java on the agent and restart the agent - it should then detect it and suggest to restart using updated Java installation.
• Install required Java on one of the agents and then replace <build agent home>\jre with the content of installed JDK home directory. (If you do not have Java builds, you may install JRE instead of JDK).

Installing Several Build Agents on the Same Machine

TeamCity treats equally all agents no matter if they are installed on the same or on different machines. However, before installing several TeamCity build agents on the same machine, please consider the following:

• Builds running on such agents should not conflict by any resource (common disk directories, OS processes, OS temp directories).
• Depending on the hardware and the builds you may experience degraded builds' performance. Ensure there are no disk, memory, or CPU bottlenecks when several builds are run at the same time.

After having one agent installed, you can install additional agents by following the regular installation procedure (see exception for the Windows service below), but make sure that:

• The agents are installed in the separate directories.
• The agents have distinctive workDir and tempDir directories in buildAgent.properties file.
• Values for name and ownPort properties of buildAgent.properties are unique.
• No builds running on the agents have absolute checkout directory specified.

Moreover, make sure you don't have build configurations with absolute checkout directory specified (alternatively, make sure such build configurations have "clean checkout" option enabled and they cannot be run in parallel).

Usually, for a new agent installation you can just copy the directory of existing agent to a new place with the exception of its "temp", "work", "logs" and "system" directories. Then, modify conf/buildAgent.properties with a new "name" and "ownPort" values. Please also clear (delete or remove value) for "authorizationToken" property.

If you want to install additional agents as services under Windows, do not opt for service installation during installer wizard or install manually (see also a feature request), then
modify the <agent>\launcher\conf\wrapper.conf file so that wrapper.console.title, wrapper.ntservice.name, wrapper.ntservice.displayname and wrapper.ntservice.description properties have unique values within the computer. Then run <agent>\bin\service.install.bat script under user with sufficient privileges to register the new agent service.
See above for the service start/stop instructions.

See also: