ubuntu - Docker-Compose can't connect to Docker Daemon

Question

I am getting an error message saying I can't connect to the docker daemon. I have looked into other people's answers who have had similar issues but it hasn't helped. I am running the version of Ubuntu 15.10. I will try to provide all the info I have.

root@# docker-compose -f docker-compose-deps.yml up -d
ERROR: Couldn't connect to Docker daemon at http+docker://localunixsocket - is it running?

If it's at a non-standard location, specify the URL with the DOCKER_HOST environment variable.

Docker Version

root@# sudo docker     version
Client:
Version:      1.9.1
API version:  1.21
Go version:   go1.4.2
Git commit:   a34a1d5
Built:        Fri Nov 20 13:20:08 UTC 2015
OS/Arch:      linux/amd64
Cannot connect to the Docker daemon. Is the docker daemon running on this host?

Docker-Compose Version

root@# docker-compose --version
docker-compose version 1.5.2, build 7240ff3

This is what happens if I try to stop or start the service...

root@# sudo service docker stop
stop: Unknown instance: 
root@# sudo service   docker start
docker start/running, process 5375

If I run ps aux | grep docker

root@# ps aux | grep docker
root      4233  0.0  0.0  13692  2204 pts/15   S+   10:27   0:00 grep --color=auto docker

Any help would be greatly appreciated. Let me know if you may need anymore information.

Answer 1

I had the same error, after 15 min of debugging. Turns out all it needs is a sudo :)

Check out Create a Docker group to get rid of the sudo prefix.