fix bug when /proc/net/dev contains unexpected line

[bo-er]

In centos 8(4.18.0-193.28.1.el8_2.x86_64) if I try this command:

ip link add team0:1 type dummy

I will get a message:

"RTNETLINK answers: Invalid argument". 

However if I do the same thing on Centos 7(3.10.0-862.14.4.el7.x86_64), there is no error ! And If I cat /proc/net/dev I can see there is a sub interface:

Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
  eth0: 2489766199  690315    0    0    0     0          0         0 96022876  713917    0    0    0     0       0          0
    lo: 402582904  916378    0    0    0     0          0         0 402582904  916378    0    0    0     0       0          0
team0:1:       0       0    0    0    0     0          0         0        0       0    0    0    0     0       0          0

So the problem is currently 'procfs' cann't parse /proc/net/dev that contains odd line of interfaces.

[discordianfish]

Interesting.. well the actual problem is that this assumes a device name can't include :: https://github.com/prometheus/procfs/pull/421/files#diff-a691799f566ae988549d796fb8df91095344d63552424e79c7687a14dcaaf601R92

But we shouldn't just ignore parse errors. Instead, if we want to fix that, we need to parse this differently.

[discordianfish]

Thanks! Can you also add test cases for dev names that include :?

[bo-er]

@discordianfish hello! 🙇🏻‍♂️ Do I need to add more test cases?

[discordianfish]

LGTM, thanks!

[discordianfish]

you need to sign your commit though before we can merge. See the DCO check

[bo-er]

you need to sign your commit though before we can merge. See the DCO check

I have signed my commits.

[SuperQ]

We should probably fix this the same way we fixed it in the node_exporter. I forgot we have yet to convert the node_exporter to this parser.

prometheus/node_exporter#904
prometheus/node_exporter#910

[SuperQ]

Actually, I like this better, it avoids use of regexp.