How to configure Docker to use a private container registry using a self-signed certificate.
Tested on Docker version 18.09.4, build d14af54.
- Copy self-signed certificate from the registry server to the docker server
On your laptop:
```bash
$ scp christian@registry-server://etc/ssl/certs/selfsigned.crt christian@docker-server://etc/ssl/certs/private-docker-registry.crt
```
- Restart docker daemon
On the docker server:
```bash
$ sudo service docker restart
```
- Login to the registry from the docker server
On the docker server:
```bash
sudo docker login -u christian registry-server
> WARNING! Your password will be stored unencrypted in /home/christian/.docker/config.json.
```