Docker Volume Mounting issues with Ruby - ruby

Question

I have a testcase where I am running an instance of Ruby inside a windows docker container. I should stress the ruby script works fine outside of docker. When run inside the docker container the script also works fine, except when the target of the Ruby file's access is on a mounted volume. In which case I get an error. I can for the testcase of course work around this issue by copying the file, but that would cause complications for the real script that found this problem.
Here's an example transcript, cbh_test is the mounted volume
PS C:\> echo ""> bob
PS C:\> cp cbh_test\failer.rb .
PS C:\> C:\Ruby25-x64\bin\ruby.exe .\failer.rb
PS C:\> cd cbh_test
PS C:\cbh_test> echo ""> bob
PS C:\cbh_test> C:\Ruby25-x64\bin\ruby.exe .\failer.rb
Traceback (most recent call last):
./failer.rb: Invalid argument # rb_readlink - C:/cbh_test (Errno::EINVAL)
Docker instance invoked by:
docker run -it -v c:\Users\me\work\fred:c:\cbh_test bob/failer powershell
Dockerfile:
# escape=`
FROM microsoft/windowsservercore:ltsc2016
SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
COPY install_ruby.ps1 c:
RUN powershell c:\install_ruby.ps1
failer.rb:
def main(args)
fragment = "bob"
$tmp = File.open(File.join(File.dirname(__FILE__), fragment), 'r+').read
end
main($ARGV)
install_ruby.ps:
$RUBY_VERSION = "2.5.3-1"
$RUBY_RELEASE = "2.5.3-1"
$url = ('https://github.com/oneclick/rubyinstaller2/releases/download/rubyinstaller-{0}/rubyinstaller-{1}-x64.exe'-f $RUBY_VERSION, $RUBY_RELEASE);
$exe = "ruby-install.exe"
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12;
Invoke-WebRequest -Uri $url -OutFile $exe;
$args = "/silent /tasks='assocfiles,modpath'"
Start-Process -FilePath $exe -ArgumentList $args -PassThru -Wait

Answer 1

I tried for several days and the only solution I was able to find to this problem was to use ltsc2019.