Docker containers keep losing internet

Question

I have configured to use docker on Centos 6.5. Quite often the containers keep losing internet. In such instances I have to restart Docker on the host. Recently, I tried to run an yum update from inside a container which failed. Following is the log from /var/log/docker

2014/07/15 10:33:36 GET /v1.12/containers/update_test/json
[b601ba8c] +job container_inspect(update_test)
[b601ba8c] -job container_inspect(update_test) = OK (0)
2014/07/15 10:33:36 POST /v1.12/containers/update_test/attach?stderr=1&stdin=1&stdout=1&stream=1
[b601ba8c] +job container_inspect(update_test)
2014/07/15 10:33:36 POST /v1.12/containers/update_test/start
[b601ba8c] +job start(update_test)
[b601ba8c] -job container_inspect(update_test) = OK (0)
[b601ba8c] +job attach(update_test)
[b601ba8c] +job allocate_interface(5a5c0247441ef5872b531ba720ba1f7d8af2df1cbd47b4a98b84a7b995384d8b)
[b601ba8c] -job allocate_interface(5a5c0247441ef5872b531ba720ba1f7d8af2df1cbd47b4a98b84a7b995384d8b) = OK (0)
[b601ba8c] -job start(update_test) = OK (0)
2014/07/15 10:33:36 POST /v1.12/containers/update_test/resize?h=37&w=165
[b601ba8c] +job resize(update_test, 37, 165)
[b601ba8c] -job resize(update_test, 37, 165) = OK (0)
[b601ba8c] +job release_interface(5a5c0247441ef5872b531ba720ba1f7d8af2df1cbd47b4a98b84a7b995384d8b)
[b601ba8c] -job release_interface(5a5c0247441ef5872b531ba720ba1f7d8af2df1cbd47b4a98b84a7b995384d8b) = OK (0)
[error] container.go:492 5a5c0247441ef5872b531ba720ba1f7d8af2df1cbd47b4a98b84a7b995384d8b: Error closing terminal: invalid argument
[b601ba8c] -job attach(update_test) = OK (0)

As mentioned above restarting Docker on the host solves the issue. I don't want to keep restarting the docker as I am planning to run a production application through docker. Anybody have any idea in this regard?

Please let me know if you need more information in this regard.

Answer 1

It is my bad that I did not mention that the host was hosted in the Rackspace. My apologies for not clarifying that (at that time I thought that it was irrelevant). It was the Rackspace's automated routine that kept messing up the iptables which obviously affected the docker routing. Rackspace did suggest to create a lock file somewhere in the /etc to prevent their automated routine touching the iptables which I have forgotten now; should not be difficult for anybody to get this from them if they experience the issue.

Answer 2

As suggested by Maduraiveeran, to prevent Rackspace from overwriting Docker's custom iptables rules you need to create a lock file in /etc. The file should be named rackconnect-allow-custom-iptables:

touch /etc/rackconnect-allow-custom-iptables

Once the lockfile has been created, restart your docker daemon with: sudo systemctl restart docker

https://support.rackspace.com/how-to/how-to-prevent-rackconnect-from-overwriting-custom-iptables-rules-on-linux-cloud-servers/