file.json

{
  "channelUri": "https://aka.ms/vs/15/release/channel",
  "channelId": "VisualStudio.15.Release",
  "productId": "Microsoft.VisualStudio.Product.Professional",
  
  "installPath": "C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Professional",
  "passive": true,
  "includeRecommended": true,
  "norestart": false,

  "addProductLang": ["en-US"],

    "add": ["Microsoft.VisualStudio.Workload.Azure",
    "Microsoft.VisualStudio.Workload.Data",
    "Microsoft.VisualStudio.Workload.DataScience",
    "Microsoft.VisualStudio.Workload.ManagedDesktop",
    "Microsoft.VisualStudio.Workload.NetCoreTools",
    "Microsoft.VisualStudio.Workload.NetWeb",
    "Microsoft.VisualStudio.Workload.Node",
    "Microsoft.VisualStudio.Workload.Office",
    "Microsoft.VisualStudio.Workload.Python",
    "Component.GitHub.VisualStudio"]
}

ps1.ps1

  $driveLetter = ((Get-Volume -FileSystemLabel "vs2017-TP").DriveLetter) + ":"
  Set-Location $driveletter
  $installFile = Join-Path $driveletter 'vs_professional.exe'
  
  # we add channel and catalog uri here instead of TP.json due to dynamic driveletter from mount.
  # --installChannelUri $($driveletter)\ChannelManifest.json
  $silentArgs = "--add Microsoft.VisualStudio.Workload.Azure --add Microsoft.VisualStudio.Workload.Data --add Microsoft.VisualStudio.Workload.DataScience --add Microsoft.VisualStudio.Workload.ManagedDesktop --add Microsoft.VisualStudio.Workload.NetCoreTools --add Microsoft.VisualStudio.Workload.NetWeb --add Microsoft.VisualStudio.Workload.Node --add Microsoft.VisualStudio.Workload.Office --add Microsoft.VisualStudio.Workload.Python --add Component.GitHub.VisualStudio --includeRecommended --passive --wait --norestart"

  start-process .\certmgr.exe -ArgumentList '-add -c certificates\manifestSignCertificates.p12 -n "Microsoft Code Signing PCA 2011" -s -r LocalMachine CA' -Wait -NoNewWindow
  start-process .\certmgr.exe -ArgumentList '-add -c certificates\manifestSignCertificates.p12 -n "Microsoft Root Certificate Authority" -s -r LocalMachine root' -Wait -NoNewWindow
  start-process .\certmgr.exe -ArgumentList '-add -c certificates\manifestCounterSignCertificates.p12 -n "Microsoft Time-Stamp PCA 2010" -s -r LocalMachine CA' -Wait -NoNewWindow
  start-process .\certmgr.exe -ArgumentList '-add -c certificates\manifestCounterSignCertificates.p12 -n "Microsoft Root Certificate Authority" -s -r LocalMachine root' -Wait -NoNewWindow
  start-process .\certmgr.exe -ArgumentList '-add -c certificates\vs_installer_opc.SignCertificates.p12 -n "Microsoft Code Signing PCA" -s -r LocalMachine CA' -Wait -NoNewWindow
  start-process .\certmgr.exe -ArgumentList '-add -c certificates\vs_installer_opc.SignCertificates.p12 -n "Microsoft Root Certificate Authority" -s -r LocalMachine root' -Wait -NoNewWindow

  start-process $installfile -ArgumentList $silentArgs -Wait -NoNewWindow

this is how i create the layout:

.\vs_Professional.exe --layout Z:\vs2017-TP-en-us-offline --includeRecommended --add Microsoft.VisualStudio.Workload.Azure --add Microsoft.VisualStudio.Workload.Data --add Microsoft.VisualStudio.Workload.DataScience --add Microsoft.VisualStudio.Workload.ManagedDesktop --add Microsoft.VisualStudio.Workload.NetCoreTools --add Microsoft.VisualStudio.Workload.NetWeb --add Microsoft.VisualStudio.Workload.Node --add Microsoft.VisualStudio.Workload.Office --add Microsoft.VisualStudio.Workload.Python --add Component.GitHub.VisualStudio --lang en-US

This 1 line ps works.

When i use ps1.ps1 (above is a snapshot of the relevant parts, at around 50% the installer dies, w/ an error where it looks like an internet url fails unreachable.
Doesn't make any sense.

I have also tried to run the vs_professional.exe with --in switch pointing the json, without success. the dd files always complain about json string issues on L11 or L13 regardless of how i position the [ or ]