On 8/30/19 8:19 AM, Nicolas Dichtel wrote:

Le 29/08/2019 à 19:30, Alexei Starovoitov a écrit :
[snip]

quoted

These are the links that showing that k8 can delegates caps.
Are you saying that you know of folks who specifically
delegate cap_sys_admin and cap_net_admin _only_ to a container to run bpf in there?

Yes, we need cap_sys_admin only to load bpf:
tc filter add dev eth0 ingress matchall action bpf obj ./tc_test_kern.o sec test

I'm not sure to understand why cap_net_admin is not enough to run the previous
command (ie why load is forbidden).

because bpf syscall prog_load command requires cap_sys_admin in
the current implementation.

I want to avoid sys_admin, thus cap_bpf will be ok. But we need to manage the
backward compatibility.

re: backward compatibility...
do you know of any case where task is running under userid=nobody
with cap_sys_admin and cap_net_admin in order to do bpf ?

If not then what is the concern about compatibility?