testcontainers-elixir fails with :badarg but testcontainers-java works - Fedora 42 / SELinux

[financelurker]

Hi, folks!

I recently started an Elixir project and due to my knowledge with Testcontainers in a Java Spring Boot application stack I stumbled over testcontainers-elixir and wanted to give it a try.

But registering testcontainers-elixir in my test_helper.exs I only gets me some :badarg error when executing mix test:
** (EXIT from #PID<0.99.0>) :badarg

What I already found out:

• Testcontainers per se works on my machine in my Java Spring Boot application project.
• This seems to be an issue in combination with SELinux. Because when temporarily disabling SELinux by using setenforce 0 then mix test actually runs without errors.
• I added ryuk.container.privileged=true to my ~/.testcontainers.properties but this does not solve the issue.

ausearch output

sudo ausearch -m AVC,USER_AVC -ts recent
----
time->Fri May  9 07:07:26 2025
type=AVC msg=audit(1746767246.443:759): avc:  denied  { write } for  pid=82782 comm="ryuk" name="docker.sock" dev="tmpfs" ino=5634 scontext=system_u:system_r:container_t:s0:c331,c534 tcontext=system_u:object_r:container_var_run_t:s0 tclass=sock_file permissive=0
----
time->Fri May  9 07:07:26 2025
type=AVC msg=audit(1746767246.444:760): avc:  denied  { write } for  pid=82782 comm="ryuk" name="docker.sock" dev="tmpfs" ino=5634 scontext=system_u:system_r:container_t:s0:c331,c534 tcontext=system_u:object_r:container_var_run_t:s0 tclass=sock_file permissive=0

So... My main question would be: What would I need to do, to make testcontainers-elixir also runnable on a system with SELinux, like the testcontainers implementation for Java?

What other information do I need to provide here, that this issue can be resolved?

Edit / Add:

• I am using docker-ce and not postman (so, I guess this is not in relation to this issue - or maybe it is, because there's also a mention of SELinux?)...
• Having compared this repository with the testcontainers-dotnet one (because the other related issue I referenced here), I can see as difference that testcontainers-dotnet actually uses the ryuk.container.privileged value from ~/.testcontainers.properties and also respects the environment variable TESTCONTAINERS_RYUK_CONTAINER_PRIVILEGED - there's no mention of these attributes within this repository... (but also not quite sure if this is an indication of why this is not working for me, because testcontainers-java works without such a config)

[jarlah]

i will see if i can get some time to look into this.

[financelurker]

Thank you, @jarlah !

Please let me know if I can help in that regard.

[jarlah]

i wonder, is it possible to reproduce this is in a virtual environment ? If you have time can you check if a clean install of fedora 42 in virtualbox or similar renders same result? If so then i can debug that, and not spend too much time on checking things in virtualbox which might never amount to something

[financelurker]

Sure, I'll try to set up such a VM in the next few days and report back.