My docker container has no internet

Question

My docker has no internet. The last time I used it was working fine. I’ve tried these following commands but not helping.

docker run -dns 8.8.8.8 base ping google.com

docker run base ping google.com

sysctl -w net.ipv4.ip_forward=1 - both on the host and on the container

All I get is unknown host google.com. Docker version 0.7.0

Any help will be appreciated..

Answer 1

Try resetting all the parameters

pkill docker
iptables -t nat -F
ifconfig docker0 down
brctl delbr docker0
docker -d

It will force docker to recreate the bridge and reinit all the network rules

Answer 2

The most common reason for this error is if the container holds an invalid DNS. Then the container will not be able to resolve the domain name into IP addresses. And hence the ping google.com will also fail. Run the following command to check for DNS server:

cat /etc/resolv.conf

Answer 3

Restarting Docker worked for me. Restart it using the following command:

service docker restart

Answer 4

If you're running Docker on OSX, do the following:

docker-machine restart
<...wait for it to restart, which takes up to a minute...>
docker-machine env
eval $(docker-machine env)

Answer 5

For me, it was the host's firewall. I had to allow DNS on the host's firewall. And also had to restart docker after changing the host firewall setting.