[SOLVED]Docker API connection refused 127.0.0.1:2376

Create a file called /etc/systemd/system/docker-tcp.socket to make Docker available on a TCP socket on port 2375.

[Unit]
Description=Docker Socket for the API

[Socket]
ListenStream=2375
BindIPv6Only=both
Service=docker.service

[Install]
WantedBy=sockets.target


Then enable this new socket:

systemctl enable docker-tcp.socket
systemctl stop docker
systemctl start docker-tcp.socket
systemctl start docker
Test that it's working:

docker -H tcp://127.0.0.1:2375 ps


Source: https://coreos.com/os/docs/latest/customizing-docker.html