Restart docker after vagrant tweaking and refactor tweak-code

Docker needs to be restarted and not started, since it already starts running after installation

test/Vagrantfile

@@ -26,15 +26,8 @@ def configure_docker(host, hostname, ip)
   host.vm.provision :shell, :inline => "echo deb https://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"
 
   install_packages host.vm, pkgs
-  host.vm.provision :shell, :inline => "usermod -a -G docker vagrant; "
-
-  # Listen on the remote API and use overlay storage driver
-  host.vm.provision :shell, :inline => "sed -i -e's%-H fd://%-H fd:// -H tcp://0.0.0.0:2375 -s overlay%' /lib/systemd/system/docker.service"
-  host.vm.provision :shell, :inline => "systemctl daemon-reload"
-
-  host.vm.provision :shell, :inline => "systemctl restart docker"
-  host.vm.provision :shell, :inline => "systemctl enable docker"
-  cleanup(host.vm)
+  tweak_docker_daemon host.vm
+  cleanup host.vm
 end
 
 def configure_resolv_conf(host)

vagrant-common.rb

@@ -47,7 +47,7 @@ def tweak_docker_daemon(vm)
 usermod -a -G docker vagrant
 sed -i -e's%-H fd://%-H fd:// -H tcp://0.0.0.0:2375 -s overlay%' /lib/systemd/system/docker.service
 systemctl daemon-reload
-systemctl start docker
+systemctl restart docker
 systemctl enable docker
 SCRIPT
 end