Running setup in background with msdeploy - powershell

Question

We're deploying build directly from TFS build to servers with msdeploy. There are many components and some of those need setup (multiple nservicebus services that take ~1min each to start/install/stop). Also this "gateway" server runs msdeploy itself to "fanout" deployment binaries to other servers that run similar setup tasks depending on their role.
It doesn't make sense for build server to be hung up on this task for a long time so we need some way to make this setup run in "background"/detached from build server perspective.
We're using powershell as deployment script engine.
So here is what we've tried:
Jobs started with start-job are killed as soon as original msdeploy -started powershell exits.
Jobs started with start-process hang up the msdeploy connection until they finish
We can't loop with invoke-command -ComputerName localhost -InDisconnectedSession (this worked from shell on same machine but not through msdeploy; I don't care for passing credentials around because we don't have DA creds and deployed machines are in multiple networks)
I post my solution below, I ended up using scheduled task that is launched immediately. But I hope somebody would know a cleaner solution.

Answer 1

This program will schedule itself to run immediately, this can be "triggered" with msdeploy runCommand and not block output.
This is our msdeploy using trigger script:
param([string]$dest = "fully.qualified.example.com",
[string]$serviceMachine = "windowsmachine",
[string]$deployUser = "webdeploy",
[string]$deployPass = "***",
[string]$localPath = "c:/temp/source",
[string]$remotePath = "c:/temp"
);
$deployCommand = "C:\Program Files\IIS\Microsoft Web Deploy V3\msdeploy.exe"
$depArgs = #('-verb:sync'
"-source:dirpath=$localPath"
"-dest:computerName=https://${dest}/msdeploy.axd,userName=$servicemachine\$deployUser,password=$deployPass,authType=basic,dirPath=$remotePath"
"-postSync:runCommand='powershell -inputformat none $remotePath/starter.ps1',waitInterval=30000"
"-enableRule:DoNotDeleteRule"
"-allowUntrusted")
$command = "& '$deployCommand' --% $depArgs"
& $ExecutionContext.InvokeCommand.NewScriptBlock($command)
and here is the starter.ps1 triggered in above:
param([switch] $fg)
$scheduledJobName = "starter_v1"
$localPath = (Get-Location).Path
$logfile = "c:\temp\starterlog.txt"
function startBGJob() {
try {
Get-ScheduledJob -Name $scheduledJobName -ErrorAction Stop
"[BGJ] Found job $scheduledJobName, starting."
# no way in PS to start the job as actual scheduled task
schtasks /run /tn "\Microsoft\Windows\PowerShell\ScheduledJobs\$scheduledJobName"
} catch {
"[BGJ] Job not found, creating and starting new"
$jobsb = {
param($lp, $logfile);
& "$lp\starter.ps1" -fg | out-file $logfile
}
$option = New-ScheduledJobOption -RunElevated
Register-ScheduledJob -name $scheduledJobName -ScriptBlock $jobsb -ArgumentList ($localPath, $logfile) -ScheduledJobOption $option -RunNow
}
}
function Main() {
if ($fg -eq $true) {
# actual work done here
} else {
startBGJob
}
}
Main
I had to extract some things from those, so typos may be within.