docker connect to windowsservercore via PowerShell remoting

Question

I want to test PS remoting between two docker containers. I've the following DockerFile:

FROM microsoft/windowsservercore:latest

# Set trusted hosts for PS remoting
RUN winrm s winrm/config/client @{TrustedHosts="*"}
# Set password -> just for testing!
RUN net user Administrator 1234!password5678

SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]

# Enable PS remoting
RUN Enable-PSRemoting -force; if ($?) {Start-Service winrm}

# Keep container alive if started via docker-compose
CMD start-sleep -seconds 3600

And the following docker-compose.yml:

version: '3.1'

services:
   testserver:
      image: 172.23.86.48/myPowerShellImage:latest
      ports:
        - 6985:5985 
        - 6986:5986   

   startpowershelltests:
      image: 172.23.86.48/myPowerShellImage:latest
      ports:
       - 7985:5985 
       - 7986:5986   
      depends_on: 
       - testserver

I start the containers via docker-compose up -d and attach me to one container via docker container exec -it powershelltoolsdocker_startpowershelltests_1 powershell.

In the attached container I perform:

 PS C:\> $pw = ConvertTo-SecureString "1234!password5678" -AsPlainText -Force
 PS C:\> $cred = new-object -typename System.Management.Automation.PSCredential  -argumentlist "testserver\Administrator", $pw
 PS C:\> $session = new-pssession -computername testserver -credential $cred

$session = new-pssession -computername testserver -credential $cred gives me the following error:

new-pssession : [testserver] Connecting to remote server testserver failed with the following error message : Access is denied. For more information, see the about_Remote_Troubleshooting Help topic.SSessionOpenFailed At line:1 char:12 + $session = new-pssession -computername testserver -credential $cred + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : OpenError: (System.Manageme....RemoteRunspace:Re moteRunspace) [New-PSSession], PSRemotingTransportException + FullyQualifiedErrorId : AccessDenied,PSSessionOpenFailed

Therefore I checked if the target is pingable:

 PS C:\> ping testserver

 Pinging testserver [172.21.162.141] with 32 bytes of data:
 Reply from 172.21.162.141: bytes=32 time<1ms TTL=128
 Reply from 172.21.162.141: bytes=32 time=2ms TTL=128
 Reply from 172.21.162.141: bytes=32 time=3ms TTL=128
 Reply from 172.21.162.141: bytes=32 time=1ms TTL=128

 Ping statistics for 172.21.162.141:
     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
 Approximate round trip times in milli-seconds:
     Minimum = 0ms, Maximum = 3ms, Average = 1ms

Can someone give me a hint what am I missing.

Thx

Answer 1

Test your connectivity between them using

Test-WSMan -ComputerName testserver -Port 7986 -credential $cred

Other things to check would include running winrm quickconfig within your images, checking if the winrm service is running within the image, and checking to make sure the correct value is in the trusted host list of your containers.

Get-Item WSMan:\localhost\Client\TrustedHosts

In a Windows domain, you don't typically need to worry about this trust, but I imagine your containers are stand-alone machines.