[SOLVED] Access shared library inside a Docker container

Access shared library inside a Docker container

Goal:
Deploying a Docker container that can access the hosts shared libraries (liblinphone.so) or can access the installation of liphone on the host.

Soft-hardware in use:
- Raspberry Pi compute module
- Mono (C#)
- Linphone with C# wrapper
- Docker

Summary:
I am writing code for a RPi3 in Mono(C#). This code uses the GPIO's and a linphone installion (a Linphone ARM version is installed on this system). The code does run flawless on native Mono. My next goal is to run it inside a Docker container. For this I did setup a private Gitlab server, Docker registry and a Gitlab pipeline to make a Docker image. The Docker image gets build without any errors. When I run the code it can't find the liblinphone.so file, obviously.. but I don't know how to.

Docker run command:

docker run --privileged -v /etc/ld.so.cache:/etc/ld.so.cache -v /etc/ld.so.conf.d/:/etc/ld.so.conf.d/ -v /usr/local/lib/:/usr/local/lib/ -v /var/run/docker.sock:/var/run/docker.sock [registry]:5000/[image]:latest

I added some volumes where the .so file and some references are located (some volumes aren't necessary). The --privileged part is to access the GPIO's.

Error:

Unhandled Exception:
System.DllNotFoundException: linphone assembly:<unknown assembly> type:<unknown type> member:(null)
  at (wrapper managed-to-native) Linphone.Core.linphone_core_set_log_level_mask(uint)
  at Linphone.Core.SetLogLevelMask (System.UInt32 mask) [0x00001] in <5285048db55d447fae3be4c32e253dbd>:0 
  at BlackBox.Phone.CreatePhone (System.String username, System.String password, System.String server, System.Int32 port, System.String agent, System.String version) [0x00001] in <5285048db55d447fae3be4c32e253dbd>:0 
  at BlackBox.BlackBox..ctor (BlackBox.BlackBox+AppFunction appFunction) [0x00198] in <5285048db55d447fae3be4c32e253dbd>:0 
  at BlackBox.MainClass.Main (System.String[] args) [0x00001] in <5285048db55d447fae3be4c32e253dbd>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.DllNotFoundException: linphone assembly:<unknown assembly> type:<unknown type> member:(null)
  at (wrapper managed-to-native) Linphone.Core.linphone_core_set_log_level_mask(uint)
  at Linphone.Core.SetLogLevelMask (System.UInt32 mask) [0x00001] in <5285048db55d447fae3be4c32e253dbd>:0 
  at BlackBox.Phone.CreatePhone (System.String username, System.String password, System.String server, System.Int32 port, System.String agent, System.String version) [0x00001] in <5285048db55d447fae3be4c32e253dbd>:0 
  at BlackBox.BlackBox..ctor (BlackBox.BlackBox+AppFunction appFunction) [0x00198] in <5285048db55d447fae3be4c32e253dbd>:0 
  at BlackBox.MainClass.Main (System.String[] args) [0x00001] in <5285048db55d447fae3be4c32e253dbd>:0

My guess is that I can't mount the linphone .so/installation. but instead that I have to mount the docker socket and run it natively on the host. also that didn't get me success (due to ignorance).

Solution

In the Dockerfile that builds the container, run the installation commands that install the package that provides the shared library.