curl -o acme.sh https://get.acme.sh
chmod a+x acme.sh
./acme.sh
Logout and log back into to get the alias that acme.sh installed.
DOMAIN=example.com
acme.sh --issue --dns -d registry.${DOMAIN}
# Create the necessary TXT record.
acme.sh --renew -d registry.${DOMAIN}
Cert is found in ~/.acme.sh/registry.${DOMAIN}/registry.${DOMAIN}.cer.
Key is found in ~/.acme.sh/registry.${DOMAIN}/registry.${DOMAIN}.key.
CA Cert is found in ~/.acme.sh/registry.${DOMAIN}/ca.cer.
The CA Cert will need to be copied to /etc/docker/certs.d/registry.${DOMAIN}/ca.crt on a host where a docker client runs so that it can trust the certificate authority.
Restart the docker daemon on the client machine.