Trace Go Network Namespace

[zhouhaibing089]

Find the thread using strace

$ strace -e trace=network -f -p <pid> -o trace.log

For example, the following output:

16652 socket(PF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 783
16652 setsockopt(783, SOL_SOCKET, SO_BROADCAST, [1], 4) = 0
16652 connect(783, {sa_family=AF_INET, sin_port=htons(6443), sin_addr=inet_addr("10.212.173.184")}, 16) = -1 ENETUNREACH (Network is unreachable)

Here 16652 is the thread ID.

Get the network namespace the thread is using

$ ls -al /proc/<pid>/task/<threadid>/ns/net

Attach to that network namespace

$ nsenter --net=/proc/<pid>/task/<threadid>/ns/net ip a s