title: docker networking namespace not visible in ip netns list
body: <p>When I create a new docker container like with </p>
  
  <pre><code>docker run -it -m 560m --cpuset-cpus=1,2 ubuntu sleep 120
  </code></pre>
  
  <p>and check its namespaces, I can see that new namespaces have been created (example for pid 7047).</p>
  
  <pre><code>root@dude2:~# ls /proc/7047/ns -la
  total 0
  dr-x--x--x 2 root root 0 Jul  7 12:17 .
  dr-xr-xr-x 9 root root 0 Jul  7 12:16 ..
  lrwxrwxrwx 1 root root 0 Jul  7 12:17 ipc -&gt; ipc:[4026532465]
  lrwxrwxrwx 1 root root 0 Jul  7 12:17 mnt -&gt; mnt:[4026532463]
  lrwxrwxrwx 1 root root 0 Jul  7 12:17 net -&gt; net:[4026532299]
  lrwxrwxrwx 1 root root 0 Jul  7 12:17 pid -&gt; pid:[4026532466]
  lrwxrwxrwx 1 root root 0 Jul  7 12:17 user -&gt; user:[4026531837]
  lrwxrwxrwx 1 root root 0 Jul  7 12:17 uts -&gt; uts:[4026532464]
  root@dude2:~# ls /proc/self/ns -la
  </code></pre>
  
  <p>When I check with  <code>ip netns list</code> I cannot see the new net namespace.</p>
  
  <pre><code>dude@dude2:~/docker/testroot$ ip netns list
  dude@dude2:~/docker/testroot$ 
  </code></pre>
  
  <p>Any idea why?</p>