support /proc/net/sockstat6 file for ipv6

[jeffrey4l]

What did you do that produced an error?

Currently, node exporter only collect socket state from /proc/net/sockstat fiile. There is another file located /proc/net/sockstat6 support ipv6. need parse this file two.

What did you expect to see?

$ curl -s localhost:9100/metrics | grep '^node_sockstat'
node_sockstat_FRAG_inuse 0
node_sockstat_FRAG_memory 0
node_sockstat_RAW_inuse 1
node_sockstat_TCP_alloc 256
node_sockstat_TCP_inuse 159
node_sockstat_TCP_mem 37
node_sockstat_TCP_mem_bytes 151552
node_sockstat_TCP_orphan 0
node_sockstat_TCP_tw 13
node_sockstat_UDPLITE_inuse 0
node_sockstat_UDP_inuse 103
node_sockstat_UDP_mem 398
node_sockstat_UDP_mem_bytes 1.630208e+06
node_sockstat_sockets_used 1613

What did you see instead?

$ curl -s localhost:9100/metrics | grep '^node_sockstat'
node_sockstat_FRAG_inuse 0
node_sockstat_FRAG_memory 0
node_sockstat_RAW_inuse 1
node_sockstat_TCP_alloc 256
node_sockstat_TCP_inuse 159
node_sockstat_TCP_mem 37
node_sockstat_TCP_mem_bytes 151552
node_sockstat_TCP_orphan 0
node_sockstat_TCP_tw 13
node_sockstat_UDPLITE_inuse 0
node_sockstat_UDP_inuse 103
node_sockstat_UDP_mem 398
node_sockstat_UDP_mem_bytes 1.630208e+06
node_sockstat_sockets_used 1613

node_sockstat_TCP6_inuse 100
node_sockstat_UDP6_inuse 10
node_sockstat_RAW6_inuse 101
node_sockstat_FRAG6_inuse 120

[SuperQ]

Seems like a good idea to me. The sockstat parsing should probably be moved to our procfs library, this would be a good opportunity to deal with it.

[SuperQ]

Looks like this was solved by #1552