Run container instance in GNS3

[CCH0124]

How run

docker run  -d     --name gns3     --net=host --privileged     -e BRIDGE_ADDRESS="172.21.1.1/24"     -v gns3-data:/data     jsimonetti/gns3-server:latest

Error message:

Error while creating node from template: Docker has returned an error: Cannot connect to unix socket /var/run/docker.sock ssl:default [Connection refused]
Error while creating node from template: Docker has returned an error: Cannot connect to unix socket /var/run/docker.sock ssl:default [Connection refused]
Error while creating node from template: Docker has returned an error: Cannot connect to unix socket /var/run/docker.sock ssl:default [Connection refused]