Im following this tutorial https://help.ubuntu.com/lts/serverguide/certificates-and-security.html#creating-a-self-signed-certificate this works fine in ubuntu 18 but not in ubuntu-core 18.
Im trying to create a CA to sign certs for etcd cluster but receive error cannot create directory read only file system.
user@core-1:~$ sudo mkdir /etc/ssl/CA
mkdir: cannot create directory ‘/etc/ssl/CA’: Read-only file system
Question: Where should the CA be created or how should it be created ?