Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/0: [Errno 2] No such file or directory

[JonathonReinhart]

Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/0: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/1: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/10: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/11: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/12: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/2: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/3: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/4: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/5: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/6: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/7: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/8: [Errno 2] No such file or directory
Error writing 'nfnetlink_log' > /proc/sys/net/netfilter/nf_log/9: [Errno 2] No such file or directory```

[JonathonReinhart]

This happens if nfnetlink_log is not loaded.

linux-netns-sysctl-verify/verify.py

Line 142 in 664dd5f

# TIP: `modprobe nfnetlink_log`

Fix with: modprobe nfnetlink_log

We should try to figure out the set of available nf_log "providers" (?) and choose one, and warn if there aren't any (and make a suggestion)