netlink: add node_network_altnames_info metric

[ajaggapa]

Creating a mapping for altnames and device names with new node_network_altnames_info

This will be used to fetch any other metrics that have only device name label but not altname.

[SuperQ]

Maybe #3540 is a better option.

[ajaggapa]

Maybe #3540 is a better option.

@SuperQ
We have both approaches, the problem i find with #3540 is that we need to use regex to match altname instead of exact match. WDYT ?

[SuperQ]

I'm not sure how a regexp is required for matching, both are additional labels so they would function the same.

[ajaggapa]

I'm not sure how a regexp is required for matching, both are additional labels so they would function the same.

altnames in #3540 is like below. If we need to fetch device of interface with altname2, then we would need to match altnames column with (altnames=*altname2*) regex/wildcard

device,altnames
eth0, "altname1,altname2,altname3"

Whereas in current PR, we have only 1 altname per row/label. So we can use altname="altname2"

altname, device
altname1, eth0
altname2, eth0
altname3, eth0