Test your Chocolatey Packages in a Windows Container

Containers are a great place to test your Chocolatey packages or even packages from another source.  You don’t have to waste time creating and tearing down vms and perhaps most importantly you can avoid those “It worked on my machine” problems.  By spinning up a clean container every time you will know all your dependencies and can specify them.  There are many approaches and this is just one example.  This article assumes you have a place to run windows containers, docker, and a minimal amount of docker experience.  You can run this on a windows 10 machine, Server 2016 with Hyper-V, or Azure.

The complete code is posted below, but lets break it up a bit and walk through small pieces and point out some of the variations on the source of the package.

In this first version we’ll look at testing a package you’ve created and assume you have the .nupkg file locally.  First, its useful to define a few variable such as the path to the nupkg file.  The $waitTime variable gives chocolatey time to install before trying to fetch the logs.  All the real work is defined in the variable $ps.  $ps contains the code that downloads and installs the the latest chocolatey client.  Next it will use that client to install the chocolatey package you defined the path to in $chocoPack.  Finally it will download and run a script from Microsoft that keeps the container running after the install so you can examine it.  (The nature of a container is to stop running after its ran some piece of code.)  We’ll get to starting the container further down.

$chocoPack = ''
$waitTime=# [int] in seconds as estimate of how long package install takes
$waitUrl='https://raw.githubusercontent.com/Microsoft/Virtualization-Documentation/master/windows-server-container-tools/Wait-Service/Wait-Service.ps1'
$ps="iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'));choco install $chocoPack -y;Invoke-WebRequest -Uri '$waitUrl' -OutFile 'c:\Wait-Service.ps1';c:\Wait-Service.ps1 -ServiceName WinRm -AllowServiceRestart"

In this next section we’ll look at installing a package from the default public package repo.  The only difference here is that $chocoPack will just contain the name of the public package.  This example installs vscode because vscode is awesome.

$chocoPack = 'vscode'
$waitTime=# [int] in seconds as estimate of how long package install takes
$waitUrl='https://raw.githubusercontent.com/Microsoft/Virtualization-Documentation/master/windows-server-container-tools/Wait-Service/Wait-Service.ps1'
$ps="iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'));choco install $chocoPack -y;Invoke-WebRequest -Uri '$waitUrl' -OutFile 'c:\Wait-Service.ps1';c:\Wait-Service.ps1 -ServiceName WinRm -AllowServiceRestart"

And the last example is using your own private chocolatey server and specifies.   In teh choco install section I’ve added the $version variable and ‘-s $privateServerURL’.  -s specifies the ‘Source’, in this case the URL to your server.

$chocoPack = 'my-package'
$version='--version 1.0.0'
$privateServerURL = 'http:///choco/nuget/'
$waitTime=# [int] in seconds as estimate of how long package install takes
$waitUrl='https://raw.githubusercontent.com/Microsoft/Virtualization-Documentation/master/windows-server-container-tools/Wait-Service/Wait-Service.ps1'
$ps="iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'));choco install $chocoPack $version -s $privateServerURL -y;Invoke-WebRequest -Uri '$waitUrl' -OutFile 'c:\Wait-Service.ps1';c:\Wait-Service.ps1 -ServiceName WinRm -AllowServiceRestart"

Now lets look at actually spinning up the container.  The first line is the actual docker command to spin up the container based on windowsservercore image and tells powershell to run the code we defined above.  It also stores the container instance ID in $cid which you will need later.  The it waits to give the package time to install.  The Invoke-command will spit out the log files about the install.  Finally you can use powershell to “remote” into the container and manually look at logs or files, etc.

($cid = docker run -d $dockerArgs microsoft/windowsservercore powershell.exe -executionpolicy bypass $ps )
Start-Sleep -Seconds $waitTime
Invoke-Command -ContainerId $cid -RunAsAdministrator -ScriptBlock{
Get-Content C:\choco\logs\choco.summary.log
#Get-Content C:\choco\logs\chocolatey.log
choco list --local-only ## list install packages
}
Enter-PSSession -ContainerId $cid -RunAsAdministrator

And here it is altogether.

$chocoPack = ''
$waitTime=# [int] in seconds as estimate of how long package install takes
$waitUrl='https://raw.githubusercontent.com/Microsoft/Virtualization-Documentation/master/windows-server-container-tools/Wait-Service/Wait-Service.ps1'
$ps="iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'));choco install $chocoPack -y;Invoke-WebRequest -Uri '$waitUrl' -OutFile 'c:\Wait-Service.ps1';c:\Wait-Service.ps1 -ServiceName WinRm -AllowServiceRestart"
($cid = docker run -d $dockerArgs microsoft/windowsservercore powershell.exe -executionpolicy bypass $ps )
Start-Sleep -Seconds $waitTime
Invoke-Command -ContainerId $cid -RunAsAdministrator -ScriptBlock{
Get-Content C:\choco\logs\choco.summary.log
#Get-Content C:\choco\logs\chocolatey.log
choco list --local-only ## list install packages
}
Enter-PSSession -ContainerId $cid -RunAsAdministrator
Its also worth noting, in these examples I’m using the -d switch in ‘docker run -d’ which tells it to run detached or in the background.  You can use -it to just jump in and watch it as well.  When I first started working with docker there were issues doing this from powersehell.  The latest version of the tools fixed this problem 🙂
UPDATE:  You can not run a full GUI version of windows server in a container so if you are trying to install an application that has dependencies on .dll files not in Server Core this may not work.
Also, since chocolately is just Powershell files to install an application, this basic process can work to install any application that can be installed on Server Core from powershell/comdmandline.

Install chef client on Windows Container and Connect to Chef Server

With a traditional windows machine the traditional “knife bootstrap windows winrm …” approach to bootstrapping works fine.  It is not however so straight forward for a container.  When you first spin up a container (assume a blank server core)  you have two methods to interact with it, Direct Powershell from the container host or the docker client, neither of which work with “knife” (in so far as I know).  You also don’t know the admin password.  There are going to be different methods to solving this problem, this is just one example that I have found to be simple and easy.  I am assuming you already have a chef server setup and have a minimal amount of familiarity with it.

Step one: Download the Validation key into a file named “validation.pem” and store it in an empty folder.  Then create a file ‘first-boot.json’ in that same folder. Contents:

{“run_list”:[]}

Of course you can add additional parameters to this file as you see fit.

You’ll also need to know your ‘chef_server_url’ and ‘validation_client_name’ (which you can get from “Generate knife Config” in the chef server.

Step two:  Spin up a container (more details on this here)

$ps = "Invoke-WebRequest -Uri 'https://raw.githubusercontent.com/Microsoft/Virtualization-Documentation/master/windows-server-container-tools/Wait-Service/Wait-Service.ps1' -OutFile 'c:\Wait-Service.ps1';c:\Wait-Service.ps1 -ServiceName WinRm -AllowServiceRestart"
($cid = docker run -d microsoft/windowsservercore powershell.exe -executionpolicy bypass $ps)

Step three: Install the chef client and connect to chef server.  There are 3 lines to update with your specific info

Invoke-Command -ContainerId $cid -RunAsAdministrator -ScriptBlock{Invoke-WebRequest -uri "https://omnitruck.chef.io/install.ps1" -OutFile c:\install.ps1;c:\install.ps1;Install}
$cPath = 'c:\'
$local = '' # update this from above
docker cp -L $local $cid`:$cPath
$chefURL = '' # update with your chef server URL
$validationClientName = '' # update this with your info
Invoke-Command -ContainerId $cid -RunAsAdministrator -ScriptBlock{
@" chef_server_url '$using:chefURL'
validation_client_name '$using:validationClientName'
file_cache_path 'c:/chef/cache'
file_backup_path 'c:/chef/backup'
cache_options ({:path => 'c:/chef/cache/checksums', :skip_expires => true})
node_name '$env:COMPUTERNAME'
log_level :info log_location STDOUT "@ | Out-File 'c:\chef\client.rb' -Encoding utf8 -Force
chef-client -c c:/chef/client.rb -j c:/chef/first-boot.json
}

That's it.  Run the following if you want to inspect the client.rb that is create for troubleshooting

$name = (((docker ps --no-trunc -a| Select-String $cid).ToString()).Normalize()).Split(" ")[-1]
$ps = "get-content c:\chef\client.rb"
docker exec $($name) powershell.exe -executionpolicy bypass $ps

Keep a Windows Container Running -Docker

The nature of a docker container is to start up, run a task, then go away.  It is uninterested in whatever service you want to run that is expected to be available to clients.  In order to keep the container running you need to give it something to do when you create the container.  This can be done with 2 simple lines of powershell.

## This string, when run by the container, will grab a script from microsoft and run it.
$ps = "Invoke-WebRequest -Uri 'https://raw.githubusercontent.com/Microsoft/Virtualization-Documentation/master/windows-server-container-tools/Wait-Service/Wait-Service.ps1' -OutFile 'c:\Wait-Service.ps1';c:\Wait-Service.ps1 -ServiceName WinRm -AllowServiceRestart"
## This will start the container and feed it the string above then while capturing the containerID that you'll want for later
($cid = docker run -d microsoft/windowsservercore powershell.exe -executionpolicy bypass $ps)
## While were at it, lets get the name of the container, it will come in handy as well
($name = (((docker $dkrRemote ps --no-trunc -a| Select-String $cid).ToString()).Normalize()).Split(" ")[-1])

The Wait-Service.ps1 file is provided by Microsoft via github.  Since this is a hosted file and could change, I would recommend downloading it and storing it on a web server you control to avoid unplanned changes.  Another alternative is to download the file and include it as part of your image build process and skipping the Invoke-webrequest part.

The variable $cid holds the ContainerID which is very useful for copying over files and restarting a container, etc.

You of course can substitute in any container image you like.  I prefer to work with a clean container.