Category: Docker

Windows Docker containers

At work, I was trying to take a C++ ISAPI DLL project and see if I can get it running in a windows container. In this blog post, I will cover my findings when working with Windows Containers – for anyone who doesn’t know there is no GUI so my blog post will cover how to do some steps using PowerShell. The end goal here is to containerize a Windows IIS legacy web app and move it to AKS without re-writing it.

I had never used Docker on a real project until now so had barely used it (please bear this in mind), please note there may and probably is a better way to do some of the following, I have written this to give you a starter for 10 if you need to work with a windows container and might need to do some legacy work.

The following are some tips on how to do stuff using windows containers and what I have been learning the last 2 weeks.

You have the option to use all manner of Windows Containers, for the work I was doing I was using the following: –


SHELL ["powershell"]
COPY SetupGregor.ps1 .
RUN powershell -File .\SetupGregor.ps1
COPY Setup C:/Setup

RUN reg import .\odbcinistuff.reg
RUN Start-Process -FilePath msodbcsql.msi -ArgumentList "IACCEPTMSSQLCMDLNUTILSLICENSETERMS=YES"

RUN Set-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Services\InetInfo\Parameters'  -Name PoolThreadLimit -Value 512 -Type DWord

# Install windows features
RUN Install-WindowsFeature NET-Framework-45-ASPNET ; \
     Install-WindowsFeature Web-Asp-Net45 ; \
     Install-WindowsFeature Web-Static-Content ; \
     Install-WindowsFeature Web-Http-Errors ; \
     Install-WindowsFeature Web-Default-Doc ; \
     Install-WindowsFeature Web-ISAPI-Filter ; \
     Install-WindowsFeature Web-Stat-Compression ; \
     Install-WindowsFeature Web-ISAPI-Ext ; \
     Install-WindowsFeature Web-ISAPI-Filter 

# IIS stuff
RUN Install-WindowsFeature Web-Mgmt-Service; \
New-ItemProperty -Path HKLM:\software\microsoft\WebManagement\Server -Name EnableRemoteManagement -Value 1 -Force; \
Set-Service -Name wmsvc -StartupType automatic; 

# Add user for Remote IIS Manager Login
RUN net user iisadmin <putyourpasswordhere> /ADD; \
net localgroup administrators iisadmin /add;

COPY Setup/LogMonitor.exe c:/LogMonitor
COPY Setup/LogMonitorConfig.json c:/LogMonitor

CMD Write-Host IIS Started... ; \
    while ($true) { Start-Sleep -Seconds 3600 }

The above are just samples of whats possible, lets cover them one by one below.

  • FROM – here I am saying use the windowsservercore-ltsc2016 windows image.
  • SHELL [“powershell”] – here since I am using a windows container I want to use the PowerShell shell.
  • COPY SetupGregor.ps1 . – here I just copy a single file into my container.
  • RUN powershell -File .\SetupGregor.ps1 – here I am running a powershell file.
  • COPY Setup C:/Setup – here I am copying a full folder into the container.
  • RUN reg import .\odbcinistuff.reg – here I exported a registry file from a test server so that I can import this into my container and use it to setup ODBC System DSN’s that I needed.
  • RUN Start-Process -FilePath msodbcsql.msi -ArgumentList “IACCEPTMSSQLCMDLNUTILSLICENSETERMS=YES” – here I am running an msi silently in my container to install ODBC sql drivers
  • RUN Set-ItemProperty -path ‘HKLM:\SYSTEM\CurrentControlSet\Services\InetInfo\Parameters’  -Name PoolThreadLimit -Value 512 -Type DWord – here is a sample on how to set a new registry key inside my windows container.
  • RUN Install-WindowsFeature NET-Framework-45-ASPNET; – yep you guessed it I’m installing windows features in my windows container.
  • RUN Install-WindowsFeature Web-Mgmt-Service; \
    New-ItemProperty -Path HKLM:\software\microsoft\WebManagement\Server -Name EnableRemoteManagement -Value 1 -Force; \ – here I am setting up the ability to connect remotely into IIS running on my container – this helps enormously when you can see the IIS settings etc from outside your windows container.
  • Set-Service -Name wmsvc -StartupType automatic; – here I make sure the service starts automatically.
  • RUN net user iisadmin <putyourpasswordhere> /ADD; \net localgroup administrators iisadmin /add; – here I create a user I can use to connect into IIS on the container – I also run the app pool using this account.
  • COPY Setup/LogMonitor.exe c:/LogMonitor
    COPY Setup/LogMonitorConfig.json c:/LogMonitor – here I am copying LogMonitor ( This is an opensource .exe which you can use to monitor logs like IIS and the event viewer etc, its a C++ project which I have built, in case
    you don’t have the tooling handy – you can find that here –
  • CMD Write-Host IIS Started… ; \
     while ($true) { Start-Sleep -Seconds 3600 } – here I keep the windows container running as long as IIS is running, if you stop IIS the container will shut down (restart the app-pool instead if you need to make changes, saves you having to restart the container.)

Buld your container using a Dockerfile like the one above:-

docker image build --tag win2016GregorsDemo .

Start your Docker image

Docker run --name remoteiisGregor -d -p 8000:80 win2016GregorsDemo 

It will start up instantly then you can get the ipaddres like so

 docker inspect --format '{{ .NetworkSettings.Networks.nat.IPAddress }}' remoteiisGregor 

Now you can connect to IIS on the container from your local desktop

Add in the IP Address and then when asked for a username and password, the username is in the Dockerfile.

Username: IISadmin
Password: ********* (whatever you add in the dockerfile)

And viola – you should now be able to connect to IIS running inside a windows container.

Now to check settings within the container you can connect to the container doing the following:-

Docker ps -a

This will give you the containerId like the following:-

Now you can grab the first 3 letters of the container id and type this

Docker exec -it 32d powershell

And now you can connect to the container with a powershell shell windows and check folders, run commands etc.

You may ask why? – Whay am I doing this, well when a customer asks if they can go to AKS with an existing solution and it needs to run on windows containers, I thought yeah let;s get it working.

This is brief blog post which doesnt go into huge detail, if you have questions please just ask, I dont have much time under my belt with Docker but I learned a lot and figure out a number of things.

What I hope to learn in first quarter of 2017

So for the first 3 months of 2107 I’m planning on learning as much @Docker as I can.

So far I have it installed on my Mac pulled down some different images and played around with Jenkins Blue Ocean and read some online articles, just some very basic stuff.

My goals for between now and end of March is as follows:-

  • Get used to the commands and try them out and see what is available
  • Read up on stuff like Swarm and the other Docker stuff which at this point I know nothing about
  • Create some basic containers and see whats possible

I have some stuff I’d like to try out and see what’s possible, how easy it is and the end goal is to have done a talk at work in February on Docker and to have learned as much as possible each week whenever possible.

I am going to be using the following links, shout out if I am missing some invaluable content, be it blogs, books or training etc.

That’s it for now, let me know if I’ve missed a great resource.

Gregor, @gregor_suttie