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:

$ 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:

$ sudo service docker restart

• Login to the registry from the docker server

On the docker server:

sudo docker login -u christian registry-server
> WARNING! Your password will be stored unencrypted in /home/christian/.docker/config.json.

How to configure Kubernetes to pull images from a private Docker registry:

• First configure Docker by following the steps outlined here:

https://snippets.aktagon.com/snippets/869-configure-docker-to-use-a-private-container-registry-using-a-self-signed-certificate

• Verify that the Docker configuration contains the authentication information

sudo cat ~/.docker/config.json
{
    "auths": {
        "<registry-server>": {
            "auth": "<hash>"
        }
    },
    "HttpHeaders": {
        "User-Agent": "Docker-Client/18.09.4 (linux)"
    }
}

• Base64 encode the config.json file

cat ~/.docker/config.json | base64 -w0 > config.base64.json

• Create secret.yml and add the contents of config.base64.json to dockerconfigjson

apiVersion: v1
kind: Secret
metadata:
 name: registrypullsecret
data:
 .dockerconfigjson: <config.base64.json>
type: kubernetes.io/dockerconfigjson

• Import the secret into Kubernetes

kubectl create -f secret.yml && kubectl get secrets

• Test that the secret was imported into Kubernetes

kubectl get secrets