Creating a VSTS build agent on an Azure DevLabs Windows Server VM with no GUI

Updates

• 28th Nov 2017: Also see this second post Creating a VSTS build agent on an Azure DevLabs Windows Server VM with no GUI - Using Artifacts
• 30th Nov 2017: Also see associated post Announcing a new VSTS Extension for Starting and Stopping Azure DevTest Labs VMs

As I posted recently I have been trying to add more functional tests to the VSTS based release CI/CD pipeline for my VSTS Extensions, and as I noted depending on how you want to run your tests e.g. trigger sub-builds, you can end up with scheduling deadlocks where a single build agent is scheduling the release and trying to run a new build. The answer is to use a second build agent in a different agent pool e.g. if the release is running on the Hosted build agent use a private build agent for the sub-build, or of course just pay for more hosted build instances. The problem with a private build agent is where to run it. As my extensions are a personal project I don’t have a corporate Hyper-V server to run any extra private agents on, as I would have for an company projects. My MVP MSDN Azure benefits are the obvious answer, but I want any agents to be cheap to run, so I don’t burn through all my MSDN credits for a single build agent. To this end I created a Windows Server 2016 VM in DevLabs (I prefer to create my VMs in DevLabs as it makes it easier tidying up of my Azure account) using an A0 sizing VM. This is tiny so cheap; I don’t intend to ever do a build on this agent, just schedule releases, so need to install few if any tools, so the size should not be an issue. To further reduce costs I used the auto start and stop features on the VM so it is only running during the hours I might be working. So I get an admittedly slow and limited private build agent but for less that $10 a month. As the VM is small it makes sense to not run a GUI. This means when you RDP to the new VM you just get a command prompt. So how do you get the agent onto the VM and setup? You can’t just open a browser to VSTS or cut and paste a file via RDP, and I wanted to avoid the complexity of having to open up PowerShell remoting on the VM. The process I used was as follows:

1. In VSTS I created a new Agent Pool for my Azure hosted build agents
2. In the Azure portal, DevLabs I created a new Windows Server 2016 (1709) VM
3. I then RDP’d to my new Azure VM, in the open Command Prompt I ran PowerShell powershell
4. As I was in my users home directory, I  cd’d into the downloads folder cd downloads
5. I then ran the following PowerShell command to download the agent (you can get the current URI for the agent from your VSTS Agent Pool ‘Download Agent’ feature, but an old version will do as it will auto update. invoke-webrequest -UseBasicParsing -uri https://github.com/Microsoft/vsts-agent/releases/download/v2.124.0/vsts-agent-win7-x64-2.124.0.zip -OutFile vsts-agent-win7-x64-2.124.0.zip
6. You can then follow the standard agent setup instructions from the VSTS Agent Pool ‘Download Agent’ feature mkdir agent ; cd agent PS Add-Type -AssemblyName System.IO.Compression.FileSystem ; [System.IO.Compression.ZipFile]::ExtractToDirectory("$HOMEDownloadsvsts-agent-win7-x64-2.124.0.zip", "$PWD")
7. I then configured the agent to run as a service, I exited back to the command prompt to do this this, so the commands were exit config.cmd

I now had an other build agent pool to use in my CI/CD pipelines at a reasonable cost, and the performance was not too bad either.