enable the remote API for dockerd

 

After completing these steps, you will have enabled the remote API for dockerd, without editing the systemd unit file in place:

1. Create a file at /etc/systemd/system/docker.service.d/startup_options.conf with the below contents:

   # /etc/systemd/system/docker.service.d/override.conf
   [Service]
   ExecStart=
   ExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2376

   Note: The -H flag binds dockerd to a listening socket, either a Unix socket or a TCP port. You can specify multiple -H flags to bind to multiple sockets/ports. The default -H fd:// uses systemd's socket activation feature to refer to /lib/systemd/system/docker.socket.

2. Reload the unit files:

   $ sudo systemctl daemon-reload

3. Restart the docker daemon with new startup options:

   $ sudo systemctl restart docker.service

4. Ensure that anyone that has access to the TCP listening socket is a trusted user since access to the docker daemon is root-equivalent.

https://success.docker.com/article/how-do-i-enable-the-remote-api-for-dockerd

https://docs.docker.com/engine/security/