After installing docker-engine on Centos-7, it failed to start by

systemctl start docker.service

After I use

systemctl status docker.service

it shows:

‚óŹ docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Fri 2016-04-01 19:07:00 CST; 3s ago
  Process: 8136 ExecStart=/usr/bin/docker daemon --storage-driver=devicemapper --storage-opt dm.datadev=/dev/direct-lvm/data --storage-opt dm.metadatadev=/dev/direct-lvm/metadata -H fd:// --insecure-registry (code=exited, status=1/FAILURE)
 Main PID: 8136 (code=exited, status=1/FAILURE)

To see more details, I use

sudo journalctl -xe

There were much more informations now:

Apr 01 19:07:00 XXX docker[8136]: time="2016-04-01T19:07:00.187369563+08:00" level=info msg="Default bridge (docker0) is assigned with an IP address Daemon option --bip can be used to set a preferred IP address"
Apr 01 19:07:00 XXX docker[8136]: time="2016-04-01T19:07:00.511949325+08:00" level=fatal msg="Error starting daemon: Error initializing network controller: Error creating default \"bridge\" network: Failed to setup IP tables, cannot acquire Interface address: Interface docker0 has no IPv4 addresses"

The ethernet interface of docker0 can not be assigned IPv4 addresse. It seems many people meet this problem after I searching the google, but none of the solutions works for me. Consequently, I find out this solution in my environment (totally remove the network bridge):

sudo ifconfig docker0 down
sudo brctl delbr docker0

and my docker service startup now!
The key is: docker-engine will not assign IP to docker0 interface which is already exists.