title: wget failure in docker container and seems http proxy doesn't work in Centos 7.3
body: <p>I met an issue: wget failure in docker container (CentOS 7.3). I seached related solution in network, and tried them, but "wget" still doesn't work.</p>
  
  <p>How to debug the issue? Anybody can help me?
  Thanks</p>
  
  <p>Detail steps as bellow:</p>
  
  <ol>
  <li>install docker-ce 17.06.0 on CentOS 7.3 </li>
  <li>set http_proxy in <code>/etc/systemd/system/docker.service.d/http-proxy.conf</code> </li>
  <li>flush changese: <code>sudo systemctl daemon-reload</code> </li>
  <li>restart Docker: <code>sudo systemctl restart docker</code> </li>
  <li>run a container </li>
  <li>in the container, ping http proxy is successful, but 'wget' failure in the docker container.</li>
  <li>try to set proxy in <code>/etc/default/docker</code>, <code>/etc/sysconfig/docker</code> and even start dockerd with http proxy. But still failure</li>
  </ol>
  
  <p>========================================================================</p>
  
  <pre><code>[root@nettra ~]# docker info|grep Proxy 
  WARNING: overlay: the backing xfs filesystem is formatted without d_type  support, which leads to incorrect behavior.
  Reformat the filesystem with ftype=1 to enable d_type support.
  Running without d_type support will not be supported in future  releases. 
  Http Proxy: http://135.245.48.34:8000/ 
  Https Proxy: http://135.245.48.34:8000/ 
  No Proxy:localhost,localhost.localdomain,127.0.0.1,135.1.29.42,135.251.50.10
  [root@nettra ~]#
  </code></pre>
  
  <p>run "wget" in host ==> successfully (by proxy 135.245.48.34:8000)</p>
  
  <pre><code>[root@nettra ~]# wget http_xxx
  --2017-07-25 12:33:23--  http_xxx
  Connecting to 135.245.48.34:8000... connected.
  Proxy request sent, awaiting response... 200 OK
  Length: unspecified [application/x-sh]
  Saving to: ‘homer_installer.sh.1’
  
      [  &lt;=&gt;                                                                            
  ] 32,671       124KB/s   in 0.3s
  
  2017-07-25 12:33:26 (124 KB/s) - ‘homer_installer.sh.1’ saved [32671]
  
  [root@nettra ~]#
  </code></pre>
  
  <p>but run "wget" in container ==> failure (it seems proxy doesn't work) [root@nettra ~]# docker run -i -t test /bin/bash</p>
  
  <pre><code>[root@dc95e2dc1597 /]# wget http_xxx
  --2017-07-25 04:38:38--  http_xxx
  Resolving cdn.rawgit.com (cdn.rawgit.com)... 198.232.125.81
  Connecting to cdn.rawgit.com (cdn.rawgit.com)|198.232.125.81|:443... failed: Connection timed out.
  Retrying.
  </code></pre>
  
  <p>ping http proxy ==> successfully</p>
  
  <pre><code>[root@dc95e2dc1597 /]# ping 135.245.48.34
  PING 135.245.48.34 (135.245.48.34) 56(84) bytes of data.
  64 bytes from 135.245.48.34: icmp_seq=1 ttl=237 time=267 ms
  64 bytes from 135.245.48.34: icmp_seq=2 ttl=237 time=252 ms
  64 bytes from 135.245.48.34: icmp_seq=3 ttl=237 time=252 ms
  64 bytes from 135.245.48.34: icmp_seq=4 ttl=237 time=252 ms
  ^C
  --- 135.245.48.34 ping statistics ---
  4 packets transmitted, 4 received, 0% packet loss, time 2999ms
  rtt min/avg/max/mdev = 252.072/255.956/267.068/6.448 ms
  </code></pre>