Microk8s manage SSL certificates DNS entries

From https://github.com/ubuntu/microk8s/issues/849

There is a file called /var/snap/microk8s/current/certs/csr.conf.template where you can add your own domain under the DNS section:

[ alt_names ]
DNS.1 = kubernetes
DNS.2 = kubernetes.default
DNS.3 = kubernetes.default.svc
DNS.4 = kubernetes.default.svc.cluster
DNS.5 = kubernetes.default.svc.cluster.local
DNS.6 = mydomain.com