VboxManage.exe spawns new window when exec run from docker-machine on windows 7

[mrkbuttyhds]

When running docker-machine with vboxmanage version 5.2.8r121009 the pre-check always fails to detect the version or capture stdout because vboxmanage.exe spawns a new window.

I have recreated this with two scripts (golang and python) and when running the "vboxmanage --version" in the cmd cli it runs okay and output is in the same window but when execing the command from the scripts causes a new window to spawn so stdout cannot be captured.

Details here; ​https://stackoverflow.com/questions/51676072/vboxmange-command-spawns-new-window-tested-with-go-os-exec-run-why-how-do

[mrkbuttyhds]

I've also just tested with virtual-box 5.2.16 and vboxmanage 5.2.16r123759

• The same problem occurs!

[Klaus Espenlaub]

This sounds like a generic issue with Windows, so it's outside the scope of this tracker. Graphical apps (those which don't have a console window) and console apps (those which show their output in a cmd.exe or similar window) don't mix since only the latter have working stdin/out/err handling. Ask Microsoft for details.

[Klaus Espenlaub]

Besides - especially from Python it'd be MUCH better if you'd directly use the VirtualBox API, and not rely on other code doing it for you. Error handling would be far superior.

[mrkbuttyhds]

The problem is this is how docker-machine runs the vboxmanage commands. So it fails and does not work! docker-machine is written in golang - in desperation to get this working I wrote the golang snippet to recreate how docker-machine calls the vboxmange.exe as per my posting above.

docker-machine source is available here; ​https://github.com/docker/machine

I will post a suggestion in a ticket open I have open with docker to use the api as an alternative.

[mrkbuttyhds]

Also I thought that vboxmanage.exe was using a console window? Is it launching as a GUI app rather than staying in the same cmd CLI?

If I run "vboxmanage --version > output.txt" it does not launch a new window!

[Valery Ushakov]

vboxmanage is just a plain console app. Try using any other such app and you'll get the same result. E.g. running the script below with pythonw:

import sys
import subprocess

sys.stdin = open("NUL", "r")
sys.stdout = open("test.out", "w")
sys.stderr = open("test.err", "w")

print "hello"
print subprocess.check_output(["C:\\Windows\\System32\\ARP.EXE", "-a"])
print "world"

will fail with

Traceback (most recent call last):
  File "test.py", line 12, in <module>
    print subprocess.check_output(["C:\\Windows\\System32\\ARP.EXE", "-a"]
  File "C:\Python27\lib\subprocess.py", line 567, in check_output
    process = Popen(stdout=PIPE, *popenargs, **kwargs)
  File "C:\Python27\lib\subprocess.py", line 703, in __init__
    errread, errwrite), to_close = self._get_handles(stdin, stdout, stderr)
  File "C:\Python27\lib\subprocess.py", line 834, in _get_handles
    p2cread = self._make_inheritable(p2cread)
  File "C:\Python27\lib\subprocess.py", line 885, in _make_inheritable
    _subprocess.DUPLICATE_SAME_ACCESS)
WindowsError: [Error 6] The handle is invalid

in test.err

[Valery Ushakov]

VBoxManage behaves just like any other Windows console program in the above test.

[Valery Ushakov]

Looking closer, you seem to need ... , stdin = sys.stdin, stderr = sys.stderr) on that subprocess.check_output call, then it works. No idea whatever that translates to in Go.

[mrkbuttyhds]

The problem appears to be environmental rather than the cause of docker, virtual box or windows. Please see thread; ​https://github.com/docker/machine/issues/4548

I found out it isn't Carbon Black causing the issue on my system!

The CB log files (confer.log) are very useful so I went looking through them. When launching vboxmanage I noticed that both docker-machine and my vboxtest.exe were being intercepted and vboxmanage was being run by windows\system32\pmlauncher.exe a google search indicated this was AVG but it isn't if you inspect the file it is described as "BeyondTrust PowerBroker for Windows Launcher".

There is a BeyondTrust PowerBroker service so I stopped this and then both the vboxtest.exe and the docker-machine commands work...

<stopped beyond trust>

C:\temp>testvbox
StdOut: "5.2.16r123759\r\n"

<started beyond trust>

C:\temp>testvbox
StdOut: ""