title: Docker. Error: Cannot start container: port has already been allocated
body: <p>I am working with Docker and when I first created a container, I managed to work with it properly. Today I rebooted my computer and set myself to work with the Docker container again. </p>
  
  <p>I tried to "activate" the container like this:</p>
  
  <pre><code>docker run -it --rm -p 5000:5000 -v `pwd`:/app myproject
  </code></pre>
  
  <p>And this is the message that I get back:</p>
  
  <pre><code>WARNING: Local (127.0.0.1) DNS resolver found in resolv.conf and containers can't use it. Using default external servers : [8.8.8.8 8.8.4.4]
  2014/07/28 12:34:32 Error: Cannot start container a152dd9040ab4be0f20ace96ba4a9b0a3c50fa89034512c2b9fcb986db912027: port has already been allocated
  </code></pre>
  
  <p>So I tried to find out what process is listening on port 5000 and kill it. Just like this:</p>
  
  <pre><code># netstat -tulpn | grep :5000
  tcp6       0      0 :::5000                 :::*                    LISTEN    3992/docker.io
  # kill -9 3992
  </code></pre>
  
  <p>I also tried restarting the docker service, like this:</p>
  
  <pre><code>sudo service docker.io restart
  </code></pre>
  
  <p>But none of these things have worked out. I am still getting the same error message when trying to activate my container:</p>
  
  <pre><code># docker run -it --rm -p 5000:5000 -v `pwd`:/app myproj
  WARNING: Local (127.0.0.1) DNS resolver found in resolv.conf and containers can't use it. Using default external servers : [8.8.8.8 8.8.4.4]
  2014/07/28 12:34:14 Error: Cannot start container b28ac5c4a425068ac1827bade6dd89e95be32f3e94c982300eba006822971ab1: port has already been allocated
  </code></pre>
  
  <p>Googling for a solution I found that this seems to be a known <a href="https://github.com/docker/docker/issues/6476">issue</a>, but maybe you can help me find a way out of this issue.</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>Just as requested by @Marcus Hughes , this is the output of <code>docker ps</code>:</p>
  
  <pre><code>$ sudo docker ps
  CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                    NAMES
  3fdfc9ecf30f        7e0ca0814a33        /bin/sh -c composer    4 hours ago         Up About an hour    0.0.0.0:5000-&gt;5000/tcp   naughty_galileo  
  </code></pre>
  
  <p>And if I do <code>docker ps -a</code>, this is what I get:</p>
  
  <pre><code>$ sudo docker ps -a
  CONTAINER ID        IMAGE                        COMMAND                CREATED              STATUS              PORTS                    NAMES
  69400a0e21f5        stenocaption-server:latest   /bin/sh -c composer    About a minute ago   Exit 0                                       agitated_feynman           
  a3c352d48ab5        stenocaption-server:latest   /bin/sh -c composer    6 minutes ago        Exit 0                                       grave_shockley             
  4c3c823bda55        stenocaption-server:latest   /bin/sh -c composer    2 hours ago          Exit 0                                       condescending_heisenberg   
  b9083a0af2cd        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       kickass_lumiere            
  0d51ea8c4377        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       sick_ritchie               
  a152dd9040ab        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       happy_thompson             
  b28ac5c4a425        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       cocky_franklin             
  d449f40487ca        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       evil_torvalds              
  b485da98ca6d        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       tender_nobel6              
  8b73b154c8aa        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       dreamy_ptolemy             
  10d327c46d95        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       boring_morse               
  a3397c0c4dfb        7e0ca0814a33                 /bin/sh -c composer    2 hours ago          Exit 0                                       thirsty_engelbart          
  e6440629fac1        7e0ca0814a33                 /bin/sh -c composer    3 hours ago          Exit 0                                       distracted_bohr            
  cb718204384e        7e0ca0814a33                 /bin/sh -c composer    3 hours ago          Exit 0                                       nostalgic_mclean           
  ca62ccc30227        7e0ca0814a33                 /bin/sh -c composer    3 hours ago          Exit 0                                       evil_heisenberg            
  83ed0727883f        7e0ca0814a33                 /bin/sh -c composer    3 hours ago          Exit 0                                       nostalgic_curie            
  1100e926ef29        7e0ca0814a33                 /bin/sh -c composer    3 hours ago          Exit 0                                       tender_nobel               
  1ed76e31d8f5        7e0ca0814a33                 /bin/sh -c composer    3 hours ago          Exit 0                                       grave_hawking              
  ad429a4ab116        7e0ca0814a33                 /bin/sh -c composer    3 hours ago          Exit 0                                       condescending_nobel        
  5790e0e9c21f        7e0ca0814a33                 /bin/sh -c composer    4 hours ago          Exit 0                                       boring_curie               
  3fdfc9ecf30f        7e0ca0814a33                 /bin/sh -c composer    4 hours ago          Up About an hour    0.0.0.0:5000-&gt;5000/tcp   naughty_galileo            
  7372b8327065        b0d5a13e5ea7                 /bin/sh -c apt-get-i   40 hours ago         Exit 127                                     high_torvalds              
  d4482ca96df9        10aac624035d                 /bin/sh -c apt-get i   40 hours ago         Exit 0                                       sad_pare                   
  0ae7489bd53e        6edd40908159                 /bin/sh -c apt-get i   41 hours ago         Exit 0                                       dreamy_davinci             
  13c1a8670908        ubuntu:14.04                 /bin/sh -c apt-get u   41 hours ago         Exit 0                                       loving_babbage             
  18e20ff7f4ec        ubuntu:14.04                 /bin/sh -c apt-get u   41 hours ago         Exit 1                                       stupefied_poincare         
  0965776b2ee9        ubuntu:14.04                 /bin/sh -c apt-get u   41 hours ago         Exit 1                                       goofy_davinci              
  aa3d871f6d1c        ubuntu:14.04                 /bin/sh -c apt-get u   41 hours ago         Exit 1                                       insane_pasteur             
  cb266936771d        ubuntu:14.04                 /bin/sh -c apt-get u   41 hours ago         Exit 1                                       distracted_turing          
  10d25a9c965b        ubuntu:14.04                 /bin/sh -c apt-get u   41 hours ago         Exit 1                                       kickass_ptolemy            
  729afe65b3f5        ubuntu:14.04                 /bin/sh -c apt-get u   42 hours ago         Exit 1                                       dreamy_tesla               
  a53c5707e667        ubuntu:14.04                 /bin/sh -c apt-get u   42 hours ago         Exit 1                                       ecstatic_bohr              
  ec97aaae1bda        ubuntu:14.04                 /bin/sh -c apt-get u   42 hours ago         Exit 1                                       romantic_bell              
  13fe8539439c        ubuntu:14.04                 /bin/sh -c apt-get u   42 hours ago         Exit 1                                       romantic_shockley          
  deaff10c2ed3        ubuntu:14.04                 /bin/sh -c apt-get u   42 hours ago         Exit 1                                       trusting_shockley          
  c49494c24595        ubuntu:14.04                 /bin/sh -c apt-get u   42 hours ago         Exit 1                                       loving_bell                
  3972c67fbd92        ubuntu:14.04                 /bin/sh -c apt-get u   42 hours ago         Exit 1                                       stupefied_euclid
  </code></pre>