nsrun

nsrun is a simple CLI utility used to run commands inside a specific process's network namespace. It can be useful when debugging processes with unnamed network namespaces (eg containers).

Build from source

To build from source and install nsrun, you can follow the instructions:

make
sudo make install

Usage

nsrun usage is really simple:

NAME:
        nsrun - execute command in given process's network namespace
                         
 
 USAGE:
        nsrun [PID] [COMMAND]

For example:

gntouts@ktb:~$ docker run -d --rm  ubuntu:latest sleep infinity
e7551fa8f7ab955b167d8728d5f0a7e2b8234c2bfff3465aa8f7d2b9ff96a96d

gntouts@ktb:~$ ps -ef | grep sleep
root      353396  353375  0 20:14 ?        00:00:00 sleep infinity

gntouts@ktb:~$ sudo nsrun 353396 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
11: eth0@if12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever