using PKCS11Interop on docker

[misaqsaadat]

Hi. I can't use PKCS11Interop on docker. I use it in windows and Ubuntu 20.02. but when I try to use it on docker, I got this error message. (when loading library)
I think my broblem is discussed at #208, but couldn't find solution.

System.DllNotFoundException: Unable to load shared library 'libdl' or one of its dependencies. In order to help diagnose loading problems, consider setting the LD_DEBUG environment variable: liblibdl: cannot open shared object file: No such file or directory
at Net.Pkcs11Interop.Common.NativeMethods.dlopen(String filename, Int32 flag)
at Net.Pkcs11Interop.Common.UnmanagedLibrary.Load(String fileName) in /src/Pkcs11Interop/Common/UnmanagedLibrary.cs
at Net.Pkcs11Interop.LowLevelAPI80.Pkcs11Library..ctor(String libraryPath) in /src/Pkcs11Interop/LowLevelAPI80/Pkcs11Library.cs
at Net.Pkcs11Interop.HighLevelAPI80.Pkcs11Library..ctor(Pkcs11InteropFactories factories, String libraryPath, AppType appType) in /src/Pkcs11Interop/HighLevelAPI80/Pkcs11Library.cs
at Net.Pkcs11Interop.HighLevelAPI80.Factories.Pkcs11LibraryFactory.LoadPkcs11Library(Pkcs11InteropFactories factories, String libraryPath, AppType appType) in /src/Pkcs11Interop/HighLevelAPI80/Factories/Pkcs11LibraryFactory.cs

[jariq]

What operating system do you use in your docker image?

[misaqsaadat]

I use mcr.microsoft.com/dotnet/aspnet:6.0 as base
I think it is based on ubuntu 20.04.
from this:
https://hub.docker.com/_/microsoft-dotnet-aspnet

[jariq]

I'm no docker expert but as I understand it microsoft-dotnet-aspnet image is available in multiple versions with multiple operating systems. If you want to use version based on Ubuntu 20.04 then you will need to use it wit 6.0-focal tag.

So instead of e.g.

docker pull mcr.microsoft.com/dotnet/aspnet:6.0

you'll need to use

docker pull mcr.microsoft.com/dotnet/aspnet:6.0-focal

[misaqsaadat]

I'm not docker expert either. dockerizing is for creating apps independent from OS. I use default Dockerfile which is create when creating new project. docker images have a OS with minimal requirements. so we should install extra packages if needed. I don't know what package I should install to use PKCS11Interop. with normal publish, it runs on windows and WSL. but when I create docker image, i get error.
PS: i use mcr.microsoft.com/dotnet/aspnet:6.0-focal. It won't help

[jariq]

In your first post you wrote that Pkcs11Interop works for you on "Ubuntu 20.02". I don't think that version is correct. Could you please provide correct version of Ubuntu where your app is working fine outside the docker?

[misaqsaadat]

I'm sorry.I mean 20.04

[jariq]

Quick update: I was able to reproduce the issue. I've created .NET 6 console app that works fine on Ubuntu 20.04 but does not work on mcr.microsoft.com/dotnet/aspnet:6.0-focal. I'm investigating the issue and will post update here once I have more details to share.

[jariq]

As it turns out mcr.microsoft.com/dotnet/aspnet:6.0-focal does not contain libdl.so but contains libdl.so.2.

You need to map libdl to libdl.so.2 in your application by using DllImportResolver delegate with NativeLibrary.SetDllImportResolver method. Sample can be seen in #168 (comment) or in Pkcs11LoggerTests project. More detailed explanation can be seen in #208 (comment).