You can run .NET/Java/Node.js/Whatever inside native Windows containers hosted on Windows servers. All you need is: Windows Server 2016 (or Windows 10), install Docker, install the Windows base image, create/run a docker image from a registry.
A new era?
There was(is?) a hype around Microsoft and .NET: C# language, .NET Framework and CLR Runtime have been open-sourced. They got Linux support. People exulted at running .NET Core applications inside Linux containers on Linux servers. Which is very cool, I’m sure. But let’s put .NET Core and tools aside otherwise I’ll end up crying (early adopters would understand).
There is an idea stuck in my head since: can we do the completely opposite act? Can we run Java inside a Windows container hosted on a Windows server? I don’t mean tools like Boot2Docker, Kitematic or new Docker Toolbox. They are all essentially a Linux VM. What I mean is native Docker experience on Windows where containers run natively without any virtualization layer.
Let’s figure it out!
Windows and Docker
We need a system running Windows Server 2016 which is Technical Preview 5 at the moment. BTW, It works on Windows 10 too, see the references below. Virtual machine works fine. In next steps we are going to enable the Container feature, install Docker and the base image. We need elevated PowerShell session on the system for that. Let’s go!
1. Install Container Feature
Install-WindowsFeature containers Restart-Computer -Force # Yeah, it's still Windows ¯\_(ツ)_/¯
2. Install Docker
Microsoft has its own fork of Docker. They ship their own versions of the docker daemon and the docker client. Let’s get them:
# Create a directory New-Item -Type Directory -Path 'C:\Program Files\Docker\' # Download the Docker daemon Invoke-WebRequest https://aka.ms/tp5/b/dockerd -OutFile $env:ProgramFiles\Docker\dockerd.exe # Download the Docker client Invoke-WebRequest https://aka.ms/tp5/b/docker -OutFile $env:ProgramFiles\Docker\docker.exe # Add the Docker directory to the system path [Environment]::SetEnvironmentVariable("Path", $env:Path + ";C:\Program Files\Docker", [EnvironmentVariableTarget]::Machine) $env:Path = [System.Environment]::GetEnvironmentVariable("Path","Machine") + ";" + [System.Environment]::GetEnvironmentVariable("Path","User") # Install as a Windows service dockerd --register-service Start-Service Docker
3. Install Base Container Image
Next we need to install the Windows Server Core base image which is provided by Microsoft and includes the core OS components. It is used as a base image by other Windows-based images.
Install-PackageProvider ContainerImage -Force Install-ContainerImage -Name WindowsServerCore -Version 10.0.14300.1000 Restart-Service docker docker tag windowsservercore:10.0.14300.1000 windowsservercore:latest
If we check installed images we will see the following picture. (Please, don’t look at the images’ sizes otherwise you’ll be scared.)
PS C:\Windows\system32> docker images REPOSITORY TAG IMAGE ID CREATED SIZE windowsservercore 10.0.14300.1000 dbfee88ee9fd 11 weeks ago 9.344 GB windowsservercore latest dbfee88ee9fd 11 weeks ago 9.344 GB
If the command executed successfully and we see the images then we are good. That’s all we need to start with container images.
Windows container images
Let’s have a look at the images that Microsoft provides:
PS C:\Windows\system32> docker search microsoft NAME DESCRIPTION STARS OFFICIAL AUTOMATED microsoft/sample-django:windowsservercore Django installed in a Windows Server Core ... 1 [OK] microsoft/dotnet35:windowsservercore .NET 3.5 Runtime installed in a Windows Se... 1 [OK] [OK] microsoft/sample-golang:windowsservercore Go Programming Language installed in a Win... 1 [OK] microsoft/sample-httpd:windowsservercore Apache httpd installed in a Windows Server... 1 [OK] microsoft/iis:windowsservercore Internet Information Services (IIS) instal... 1 [OK] [OK] microsoft/sample-mongodb:windowsservercore MongoDB installed in a Windows Server Core... 1 [OK] microsoft/sample-mysql:windowsservercore MySQL installed in a Windows Server Core b... 1 [OK] microsoft/sample-nginx:windowsservercore Nginx installed in a Windows Server Core b... 1 [OK] microsoft/sample-python:windowsservercore Python installed in a Windows Server Core ... 1 [OK] microsoft/sample-rails:windowsservercore Ruby on Rails installed in a Windows Serve... 1 [OK] microsoft/sample-redis:windowsservercore Redis installed in a Windows Server Core b... 1 [OK] microsoft/sample-ruby:windowsservercore Ruby installed in a Windows Server Core ba... 1 [OK] microsoft/sample-sqlite:windowsservercore SQLite installed in a Windows Server Core ... 1 [OK]
It’s long enough for the start: .NET, IIS, Go, Python, Ruby, MySQL, … Wait! Where’s Java? How come??? Okaaay, Let’s create it by ourselves.
4. Create an image with Java
Create a Dockerfile,
c:\java-windows-docker\Dockerfile, and put the following lines inside:
FROM windowsservercore RUN powershell (new-object System.Net.WebClient).Downloadfile('http://javadl.oracle.com/webapps/download/AutoDL?BundleId=210185', 'C:\jre-8u91-windows-x64.exe') RUN powershell start-process -filepath C:\jre-8u91-windows-x64.exe -passthru -wait -argumentlist "/s,INSTALLDIR=c:\Java\jre1.8.0_91,/L,install64.log" RUN del C:\jre-8u91-windows-x64.exe CMD [ "c:\\Java\\jre1.8.0_91\\bin\\java.exe", "-version"]
It downloads the Java 8 Update 91 Windows installer and silently installs it to
c:\Java\jre1.8.0_91. After start, the container launches Java and prints out its version.
Let’s build the image:
docker build -t java-windows-docker c:\java-windows-docker
And if we run it…
PS C:\Windows\system32> docker run java-windows-docker java version "1.8.0_91" Java(TM) SE Runtime Environment (build 1.8.0_91-b15) Java HotSpot(TM) 64-Bit Server VM (build 25.91-b15, mixed mode)
We have Java running. Wow! Amazing!! We have Java running inside a Windows docker container which is hosted on a Windows server. Frankly, I wouldn’t believe this a couple of years ago. But things got real now!
What about Linux containers on Windows server? Unfortunately they aren’t supported. You will get an error if you try to pull/run one. But, it won’t surprise me if we could run .NET Core inside a Linux container on a Windows server sometime. Such a crazy time to code!
Channel 9: Containers 101 with Microsoft and Docker
GitHub: .NET Core Docker Images
GitHub: Windows Containers samples