Docker Swarm and self-signed Docker Registry

Question

I've created my cluster, it uses swarm master/nodes running inside containers.

It works well, but as soon as I try to login to my Docker Registry I'm getting error message:

$ docker -H :4000 login https://...:443
...
Error response from daemon: Get https://.../v1/users/: x509: certificate signed by unknown authority

Whats the issue?

Answer 1

Add your self signed cert to the list of trusted certificates on the host. For some reason, docker doesn't use the certificates on the daemon for this authentication. Here are the commands for a debian host:

sudo mkdir -p /usr/local/share/ca-certificates
sudo cp ca.pem /usr/local/share/ca-certificates/ca-local.crt
sudo update-ca-certificates
sudo systemctl restart docker

The docker restart at the end is required for the daemon to reload the OS certificates.