How to start Docker daemon on Ubuntu?

Question

On Windows, I've always been able to build Docker images with no problems.

I'm now trying to build a simple Docker image on Ubuntu 18.04 and typing in the terminal:

sudo docker build -t test .

results in the following error:

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. 
Is the docker daemon running?

How do I start the Docker daemon? I want to be able to build the image successfully

EDIT:

Typing sudo systemctl start docker as stated in the original documentation https://docs.docker.com/config/daemon/systemd/ results in the following error:

Failed to start docker.service: Unit docker.service is masked.

@leopal doing sudo systemctl start docker results in Failed to start docker.service: Unit docker.service is masked. — Employee, Feb 11 '19 at 12:46
[Check this](https://ubuntuforums.org/showthread.php?t=2393309) — leopal, Feb 11 '19 at 12:56
Try running the following : sudo systemctl unmask docker.service sudo systemctl unmask docker.socket sudo systemctl start docker.service — Yonah Dissen, Feb 11 '19 at 12:59

score 12 · Accepted Answer · answered Feb 11 '19 at 13:57

12

You can configure docker to start on boot :

sudo systemctl enable docker

The ugly way : start docker manually :

dockerd &

answered Feb 11 '19 at 13:57

Zak

1 Answers1