Not able to connect to network inside docker container

Question

I have a CentOS 7 host on which I am running Docker. When I do a ping from my host to 8.8.8.8, ping was successful whereas same inside a docker container is not working.

From Host

[root@linux1 ~]# ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=47 time=31.5 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=47 time=31.6 ms
^C
--- 8.8.8.8 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 31.592/31.617/31.643/0.179 ms

From Docker Container (I am using basic ubuntu image):

[root@linux1 ~]# docker run ubuntu ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 172.17.0.1 icmp_seq=1 Destination Host Unreachable
From 172.17.0.1 icmp_seq=2 Destination Host Unreachable
From 172.17.0.1 icmp_seq=3 Destination Host Unreachable
From 172.17.0.1 icmp_seq=4 Destination Host Unreachable
^C
--- 8.8.8.8 ping statistics ---
6 packets transmitted, 0 received, +4 errors, 100% packet loss, time 5000ms
pipe 4

Any suggestions would be helpful. Thanks

Answer 1

Restart the Docker daemon on Debian9

service docker restart

and the connections and networks works fine

Answer 2

Recently I faced a similar network issue. The other answers here didn't help: DNS was working fine and restarting Docker wouldn't change a thing. I've found that specifying the network as host solved it.

There are three ways of doing it:

In docker-compose:

By setting network_mode in the yaml file:

services:
  worker:
    build: .
    network_mode: host

In the image building stage for RUN commands:

docker build --network=host

In the execution stage for the application:

docker run --network=host <image>