FATA[0000] Error: v1 ping attempt failed with error: Get https://dl.dockerpool.com:5000/v1/_ping: tls: oversized record received with length 28012. If this private registry supports only HTTP or HTTPS with an unknown CA certificate, please add --insecure-registry dl.dockerpool.com:5000 to the daemon’s arguments. In the case of HTTPS, if you have access to the registry’s CA certificate, no need for the flag; simply place the CA certificate at /etc/docker/certs.d/dl.dockerpool.com:5000/ca.crt