Docker Daemon not connecting

I am using Ubuntu Bionic - 18.04.
I have copied project from git repository and trying to do sudo docker-compose build but getting error as :
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.

If I do sudo apt install docker-ce then :
docker-ce is already the newest version (18.06.1~ce~3-0~ubuntu).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

If I do docker info then I get:
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

If I do sudo service docker start then I get:
*** Starting Docker: docker [ OK ]**

If I do docker info then I get :
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

If I do sudo docker-compose build then again I get:
elasticsearch uses an image, skipping
adminer uses an image, skipping
db uses an image, skipping
Building django
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.

This project is currently working fine on server. Any suggestions?
I am stuck from here dont know what to do? If any further information needed please ask. Thanks.

Looks like your daemon is crashing or refusing to start for some reason. Maybe some invalid options in your daemon.json file. What do you see if you run sudo service docker status?

After I do sudo service docker status

  • Docker is not running

Then if I do sudo service docker start

Then I get

  • Starting Docker: docker [ OK ]

Then again if I do sudo service docker status

  • Docker is not running