OCI runtime exec failed

[mjura]

In latest version of lockc we can observer new issue:

mjura@gecko:~/lockc> kubectl exec -ti myapp-57654f69bc-gdbmc -- bash
error: Internal error occurred: error executing command in container: failed to exec in container: failed to start exec "654039d5bb775cac6e717e909241b4f63fca71fae92be6031e54ba8638a16576": OCI runtime exec failed: exec failed: container_linux.go:380: starting container process caused: process_linux.go:99: starting setns process caused: fork/exec /proc/self/exe: operation not permitted: unknown

How to reproduce it:

1. Deploy Kubernetes cluster
2. Deploy example application deployment, e.g.: kubectl create deployment test --image=nginx
3. Install lockc
4. Try to connect to application deployment with kubectl exec -ti test-<POD_NAME> -- sh
5. You should see following error

error: Internal error occurred: error executing command in container: failed to exec in container: failed to start exec "654039d5bb775cac6e717e909241b4f63fca71fae92be6031e54ba8638a16576": OCI runtime exec failed: exec failed: container_linux.go:380: starting container process caused: process_linux.go:99: starting setns process caused: fork/exec /proc/self/exe: operation not permitted: unknown