PowerShell core is the edition of PowerShell built on top of .NET Core. It is sometimes simplified to CoreCLR, though it technically includes CoreFX as well.

PowerShell Core is cross-platform, available on Windows, macOS, and Linux, thanks to the cross-platform nature of .NET Core. On PowerShell Core, $PSVersionTable.PSEdition is set to Core.

Do note that while PowerShell Core 6.0 is cross-platform, there is also a PowerShell Core 5.0/5.1 released exclusively as part of Nano Server. Current version of PowerShell core is 7.1 with 7.2 available under preview. In this blog post, we’ll learn how to run PowerShell core in a docker container.

First of all, we need to search for PowerShell core related images that are available. So you can search by https://hub.docker.com https://hub.docker.com/_/microsoft-powershell or you can also search using the docker command.

There are different images created in order to support the variety of the OS platforms. You can find the appropriate versions as per your underlying OS distribution. The default latest tag is attributed to ubuntu 18.04 for linux OS and windows server core for Windows OS.

Alternatively, if you are using docker desktop on your machine, you can use docker cli to search for the images suitable for your distribution. Below is the command to use while searching from a bash prompt with docker cli:

docker search powershell --no-trunc

where --no-trunc specifies that output should not be truncated. It should throw an output like below:

mohitgoyal@DESKTOP:~$ docker search powershell --no-trunc
NAME                                           DESCRIPTION                                                                                            STARS     OFFICIAL   AUTOMATED
microsoft/powershell                           PowerShell for every system!                                                                           146                  [OK]
centos/powershell                              PowerShell is a cross-platform (Windows, Linux and OS X) automation and configuration tool/framework   8                    [OK]
microsoft/powershell-nightly                   Nightly builds of PowerShell Core for CI                                                               7                    [OK]
tylerl0706/powershell-code-server              Coder.com's code-server, PowerShell, and the PowerShell extension for vscode                           2                 
scotta01/powershell                            Powershell on Ubuntu 16.04                                                                             2                    [OK]
pshorg/powershellcommunity                     PowerShell for every system!  Community Images!                                                        2                 
jess/powershell                                                                                                                                       2                 
quickbreach/powershell-ntlm                    Read more https://blog.quickbreach.io/ps-remote-from-linux-to-windows/                                 2                    [OK]
uleenucks/powershell                                                                                                                                  1                 
10thmagnitude/powershell-azure                 Microsoft's official Docker image of Powershell with the Azure Powershell tools added.                 1                    [OK]
andschwa/powershell                            PowerShell automated builds.                                                                           1                    [OK]

Here, we can see that many types of images are available. We would choose to go with the image named microsoft/powershell, because 1) In description we can see that it is officially release by Microsoft itself 2) It has highest number of stars rating.

Now, to pull the specified image, we can use below command:

docker pull microsoft/powershell
docker pull mcr.microsoft.com/powershell:latest

We can now see that docker will start pulling all associated intermediate layers and start creating the image:

mohitgoyal@DESKTOP:~$ docker pull mcr.microsoft.com/powershell:latest
latest: Pulling from powershell
a70d879fa598: Pull complete
c4394a92d1f8: Pull complete
10e6159c56c0: Pull complete
274c216daa46: Pull complete
5ed006f3c539: Pull complete
2e546646cc81: Pull complete
Digest: sha256:644c6f2a82c6df1bf30e475994f3a7f97085903e4cb9c8b6727df33b1485627e
Status: Downloaded newer image for mcr.microsoft.com/powershell:latest
mcr.microsoft.com/powershell:latest

Once its done, we should be able to see the image in docker images list:

mohitgoyal@DESKTOP:~$ docker images
REPOSITORY                     TAG       IMAGE ID       CREATED        SIZE
mcr.microsoft.com/powershell   latest    e94455db57dd   4 weeks ago    329MB

Now, we can create a container by using below command:

docker run -it microsoft/powershell:latest powershell
docker run --name powershell --rm -it mcr.microsoft.com/powershell

mohitgoyal@DESKTOP:~$ docker run --name powershell --rm -it mcr.microsoft.com/powershell
PowerShell 7.1.3
Copyright (c) Microsoft Corporation.

https://aka.ms/powershell
Type 'help' to get help.


PS /> Write-Host "Say Hello to PowerShell"
Say Hello to PowerShell
PS /> exit

As we can see that current version of PowerShell for the image we pulled is 7.1.3. We can now run PS commands as we need.