This happens when the Jenkins user is not added to the docker group. So first try to create a Jenkins user and add the user to the docker group. Follow the below steps:
1. Create a docker group if you haven’t done it already.
$ sudo groupadd docker
2. Create a Jenkins user and add it to the docker group.
$ sudo usermod -aG docker $USER
3. Log off, restart your Jenkins and try executing the program. If you’re still getting the same error then change the access permission of the /var/run/docker.sock by using the following command.
$ chmod 777 /var/run/docker.sock