“docker pull” certificate signed by unknown authority

Question

I was trying to pull a docker image from a docker registry but hit the following issue:

$ docker pull //          


        

Answer 1

Here is a quick solution:

• Edit or create the file /etc/docker/daemon.json and add insecure-registries :

example for docker.squadwars.org:

{
    "insecure-registries" : ["docker.squadwars.org:443"]
}

• Restart docker daemon

systemctl restart docker

• Create a directory with the same name of the host .

example for docker.squadwars.org:

mkdir -p /etc/docker/certs.d/docker.squadwars.org

• Get the certificate and save it to the created directory.

ex +’/BEGIN CERTIFICATE/,/END CERTIFICATE/p’ <(echo | openssl s_client -showcerts -connect docker.squadwars.org:443) -scq > /etc/docker/certs.d/docker.squadwars.org/docker_registry.crt