* Instead of storing just a server_url which was necessary to
regenerate the OpenVPN configs, instead store an env file.
* Move all the env parsing to `ovpn_genconfig` so that it can be re-run
from genconfig instead of from `ovpn_init`.
* Remove all the parsing and env defaults except for genconfig.
NOTE: This breaks the older config method, uesrs will need to re-run
genconfig with an arg[1] as the previous server_url, this will create
the necessary env file the rest of the tools expect.
Example recovery for legacy users:
host$ docker run --rm -it kylemanna/openvpn bash -l
container# ovpn_genconfig $(cat /etc/openvpn/server_url)
* Previously the server name cached the common name generated during
init and assumed always 1194/udp.
* The new configuration allows for users to pass in a url in a new form
that allows the protocol to be specified as well as the port.
* Example: udp://vpn.example.com:1194
* Try to be backwards compatible.
* Protect the CA key with a passphrase by default to protect it from a
filsystem compromise. An attacker could still steal the other keys
stored (ie the server's cert key), but not issue new keys.
* This is a good compromise for now.
* Disable auto guessing the external IP in favor of the user explicitly
specifying the server name. Save the servername for client cert
generation later.
* Remove dnsutils from build since dig is no longer necessary. Favor
learn and mean images.
