Support ltsc 2025 images (Nano, Servercore and Server)

[jpatigny]

Summary of the new feature / enhancement

Add images for windows server ltsc2025 on all 3 flavours of images (nanoserver, servercore and server)

All upstream images are available 👍🏻

upstream image	powershell image
mcr.microsoft.com/windows/server:ltsc2025	mcr.microsoft.com/powershell:windowsserver-ltsc2025
mcr.microsoft.com/windows/servercore:ltsc2025	mcr.microsoft.com/powershell:windowsservercore-ltsc2025
mcr.microsoft.com/windows/nanoserver:ltsc2025	mcr.microsoft.com/powershell:nanoserver-ltsc2025

Proposed technical implementation details (optional)

No response

[chadlwilson]

I wonder if there is any chance of this being addressed or some help that might be needed?

The official powershell images are quite convenient as base images since winget isn't available on servercore/nanoserver and using pwsh 7+ as a baseline for scripting builds and as the default CMD is convenient.

[chadlwilson]

Docker-native workaround

For anyone building their own child image anyway, and looking for a docker-native workaround for this that doesn't involve pulling releases from Github etc; it is possible to use a multi stage build like this.

# escape=`
FROM mcr.microsoft.com/powershell:lts-windowsservercore-ltsc2022 as powershell
FROM mcr.microsoft.com/windows/servercore:ltsc2025

# See https://github.com/PowerShell/PowerShell-Docker/blob/master/release/7-6/windowsservercore2022/docker/Dockerfile
ENV ProgramFiles="C:\Program Files" `
    POWERSHELL_TELEMETRY_OPTOUT=1 `
    POWERSHELL_UPDATECHECK=0
COPY --from=powershell "$ProgramFiles\PowerShell\latest" "$ProgramFiles\PowerShell\latest"
RUN setx /M PATH "%ProgramFiles%\PowerShell\latest;%PATH%;"

RUN pwsh -Command "Write-Host hello"

Alternative direct download

Pretty slow due to lack of mature Docker Windows buildkit support and the size of images though. Probably would have been better to just lift this direct unpacking part if you're OK with direct Github releases downloads:

PowerShell-Docker/release/7-6/windowsservercore2022/docker/Dockerfile

Lines 11 to 35 in c074f94

	FROM mcr.microsoft.com/${WindowsServerCoreRepo}:${tag} AS installer-env
	ARG PS_VERSION=6.2.0
	ARG PS_PACKAGE_URL=https://github.com/PowerShell/PowerShell/releases/download/v${PS_VERSION}/PowerShell-${PS_VERSION}-win-x64.zip
	SHELL ["C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe", "-command"]
	ARG PS_PACKAGE_URL_BASE64
	RUN Write-host "Verifying valid Version..."; `
	if (!($env:PS_VERSION -match '^\d+\.\d+\.\d+(-\w+(\.\d+)?)?$' )) { `
	throw ('PS_Version ({0}) must match the regex "^\d+\.\d+\.\d+(-\w+(\.\d+)?)?$"' -f $env:PS_VERSION) `
	} `
	$ProgressPreference = 'SilentlyContinue'; `
	if($env:PS_PACKAGE_URL_BASE64){ `
	Write-host "decoding: $env:PS_PACKAGE_URL_BASE64" ;`
	$url = [System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String($env:PS_PACKAGE_URL_BASE64)) `
	} else { `
	Write-host "using url: $env:PS_PACKAGE_URL" ;`
	$url = $env:PS_PACKAGE_URL `
	} `
	Write-host "downloading: $url"; `
	[Net.ServicePointManager]::SecurityProtocol = [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls12; `
	Invoke-WebRequest -Uri $url -outfile /powershell.zip -verbose; `
	Expand-Archive powershell.zip -DestinationPath \PowerShell

Alternative with Scoop

..but I ended up switching to using scoop to install pwsh since I am using that for other tools anyway and winget isnt available for Windows Server Core:

# escape=`
FROM mcr.microsoft.com/windows/servercore:ltsc2025
ENV POWERSHELL_TELEMETRY_OPTOUT=1 `
        POWERSHELL_UPDATECHECK=0

SHELL ["powershell", "-Command"]
RUN Write-host 'Installing scoop + pwsh...'; `
    $ErrorActionPreference = 'Stop'; `
    $ProgressPreference = 'SilentlyContinue'; `
    iex \"& {$(irm get.scoop.sh)} -RunAsAdmin \"; `
    scoop install pwsh

SHELL ["pwsh", "-Command"]
RUN Write-Host hello