ioi/isolate

"No such file or directory" issue when trying to run C# program using Dotnet

Closed this issue · 7 comments

subhtak commented

isolate --cg -p --chdir=CSHARP11_BASIC/src --open-files=1024 -E HOME=tmp --box-id=555 --run -- /usr/local/dotnet-sdk/dotnet run

MSBUILD : error MSB1025: An internal failure occurred while running MSBuild.
System.IO.IOException: No such file or directory

Microsoft.Build.CommandLine.MSBuildApp.Execute(String[] commandLine)
Unhandled exception: System.IO.IOException: No such file or directory
   at Interop.Sys.TryGetUserNameFromPasswd(UInt32 uid, Byte* buf, Int32 bufLen, String& username)
   at Interop.Sys.GetUserNameFromPasswd(UInt32 uid)
   at System.Environment.get_UserName()

Thank you in advance

gollux commented

dotnet is very peculiar in many senses and it is hard to get it running within a sandbox. I tried that a few months ago and the results is issue 1243 in CMS repository, which documents all the roadblocks I encountered.

In this case, you need to provide /etc/passwd with entries for the UIDs used by the sandbox.

subhtak commented

@gollux thanks for the reply. Attached is the /etc/passwd. I don't have much idea how to add user account specific to this usecase. Pls suggest.
passwd.txt

gollux commented

Look at Isolate's configuration file and find the UID range used for sandboxes. Add corresponding entries to passwd.

subhtak commented

Hey @gollux

I am not very clear with how to make the entry there in etc/passwd as the created user info is not known. Following fields are required separated by colon (:)

  1. Encrypted Password
  2. UID number
  3. Default GID number
  4. user information: full name, office, phone, …
  5. Home directory
  6. Login shell

I am not able to find out the process id nor the uid/gid when the isolate command is run.
This is the range I have in config:

Block of UIDs and GIDs reserved for sandboxes
first_uid = 60000
first_gid = 60000
num_boxes = 50000

Please help @gollux

gollux commented

You do not need a process ID, just the user ID. You can determine it by running /usr/bin/id -a in the sandbox, or compute it as a sum of first_uid from the configuration with the ID of the sandbox you are starting (if you do not specify an explicit ID, it defaults to 0).

  • 👍1
subhtak commented

Thanks @gollux. After making the required entry in the /etc/passwd, the issue is resolved and dotnet commands are working inside isolate. But everytime making an entry in the /etc/passwd for every code execution is not great idea. I hope we can find a more optimal solution for this.

gollux commented

Just add the required users to /etc/passwd in the host system.