Dockerfile: adding eBPF support in iproute

[alban]

$ sudo docker run docker.io/albanc/tcd:demo1 tc filter add dev wlp3s0 parent 1: bpf obj bpf_shared.o sec egress help
No ELF library support compiled in.
Could not load object

We will need that support for experimenting with eBPF. Ideally, the alpine image should be fixed.

Same issue in other Linux distributions:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=812774
https://bugzilla.redhat.com/show_bug.cgi?id=1290384

[alban]

http://bugs.alpinelinux.org/issues/5673

[alban]

https://bugs.alpinelinux.org/issues/5673 has been fixed. We should get the new image and test it.