GoCD: Automate Agent Install with PowerShell
I have been setting up build servers and I have been exploring automating the process. So, I have been scripting every step I take to stand the servers up. In this post I will sharing some of the commands I use to create GoCD Agents. If you decide to go down this road, you should think about creating reusable scripts and parameterize the things that change (I didn’t want to do all the work for your :). Also, it would make sense to use a configuration manager like DSC, Puppet or Chef to actually run the scripts.
I am using PowerShell remotely on the build servers, which is indicated by [winbuildserver1]: PS> in the command prompt. Check out my previous post to learn more about configuring remote servers with PowerShell.
Copy Install Files
The first thing I do is copy the install files from the artifact repository to the server.
[winbuildserver1]: Copy-Item -Path \\artifactserver\d$\repository\Go-Agent\go-agent-14.1.0-18882\go-agent-14.1.0-18882-setup.exe -Destination "D:\install-temp\" -Recurse -Force
[winbuildserver1]: PS>([WMICLASS]"Win32_Process").Create("D:\install-temp\go-agent-14.1.0-18882-setup.exe /S /SERVERIP=<ip of go server> /GO_AGENT_JAVA_HOME=<path to JRE> /D=D:\Go Agents\Internal\1\")
Here we are getting a reference to the static WMI class “Win32_Process”, call the create method passing the command line to install an agent (http://www.thoughtworks.com/products/docs/go/current/help/installing_go_agent.html). In the command line we have
- the path to the install file
- /S switch for silent install (no user prompts)
- /SERVERIP switch for the IP of the Go Server (this is optional)
- /GO_AGENT_JAVA_HOME switch for the path to the JRE (this is optional)
- /D switch is the path to location you want to install the agent.
Run Multiple Agents on Same Server
If I want to run multiple agents on the same server I do a little extra work to get the other agents installed.
[winbuildserver1]: PS> Copy-Item "D:\Go Agents\Internal\1\*" -Destination "D:\Go Agents\PCI\1"
[winbuildserver1]: PS> Remove-Item "D:\Go Agents\PCI\1\config\guid.txt"
[winbuildserver1]: PS> Remove-Item "D:\Go Agents\PCI\1\.agent-bootstrapper.running"
Here we are just copying an installed agent to a new location and removing a couple files to force the agent to recreate and register itself with the server.
Create Agent Service
Lastly, I create a service for the agent.
[winbuildserver1]: PS> New-Service -Name "Go Agent PCI 1" -Description "Go Agent PCI 1" -BinaryPathName "`"D:\Go Agents\PCI\1\cruisewrapper.exe`" -s `"D:\Go Agents\PCI\1\config\wrapper-agent.conf`""
Get more on using PowerShell to configure services in my previous post.
I use similar commands to install the server, plug-ins, and other tools and services (e.g. Git, SVN, NuGet…) that I need on the build server. I have to admit that this isn’t totally automated yet. I still have to manually update the service account, credentials and manually accept a certificate to get SVN working with the agent, but this got me 90% done. I don’t have to worry about my silly mistakes because the scripts will do most of the work for me.