Docker HTTP (insecure) registry

By default Docker refuses to push/pull from registries that are not served using HTTPS.

To enable Docker to push to registries served over HTTP, the address of the registry must be appended to the insecure-registries Array of the /etc/docker/daemon.json file. If the file does not exist, it must be created.

Here is an example:

{
  "insecure-registries" : ["IP:PORT"]
}

Docker must be restarted after changes to /etc/docker/daemon.json have been done:

sudo systemctl restart docker