I installed and oepnvpn on an Ubuntu server 16.04 by following the following guideline
how-to-set-up-an-openvpn-server-on-ubuntu

When I start the openVPN server with: service openvpn start it looks like it get started, but I get no log files written even though I have the log option activated.

status /var/log/openvpn-status.log
log /var/log/openvpn.log 

Any hints what I can try?

• how can I check if the process/service is really running?


• how can I find out if the service is crashing every time?


• any idea why the log files don't get written?

output on starting the service

root@Diabolo:/etc/openvpn# service openvpn stop
root@Diabolo:/etc/openvpn# service openvpn start
root@Diabolo:/etc/openvpn# service openvpn status
openvpn.service - OpenVPN service
Loaded: loaded (/lib/systemd/system/openvpn.service; enabled; vendor preset: enabled)
Active: active (exited) since Sat 2016-06-25 19:04:12 CEST; 3s ago
Process: 3956 ExecStart=/bin/true (code=exited, status=0/SUCCESS)
Main PID: 3956 (code=exited, status=0/SUCCESS)
Jun 25 19:04:12 Diabolo systemd[1]: Starting OpenVPN service...
Jun 25 19:04:12 Diabolo systemd[1]: Started OpenVPN service.

output on syslog

Jun 25 19:04:12 Diabolo systemd[1]: Starting OpenVPN service...
Jun 25 19:04:12 Diabolo systemd[1]: Started OpenVPN service.

config file server.conf

port 1194
proto udp
dev tun
ca /etc/openvpn/ca.crt
cert /etc/openvpn/server.crt
key /etc/openvpn/server.key 
dh /etc/openvpn/dh2048.pem
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
push "redirect-gateway def1 bypass-dhcp"
push "dhcp-option DNS 208.67.222.222"
push "dhcp-option DNS 208.67.220.220"
keepalive 10 120
comp-lzo
max-clients 100
user nobody
group nogroup
persist-key
persist-tun
status /var/log/openvpn-status.log
log /var/log/openvpn.log
verb 3

The problem is that service config /lib/systemd/system/openvpn.service just calls /bin/true (I have no idea on why it wasn't just removed).
Usable configuration might be found in /lib/systemd/system/openvpn@.service, but it still needs to be somewhat hacked.

Solution that worked for me:

1. Create dependency on networking service

To protect it from overwriting, create it in a separate file in subdirectory:

 mkdir -p /lib/systemd/system/openvpn@.service.d

Create a file in this directory. Its name must end with .conf, for example:

 vi /lib/systemd/system/openvpn@.service.d/local-after-ifup.conf

Put following content in this file:

[Unit]
Requires=networking.service
After=networking.service

2. Try to start the server

systemctl start openvpn@<CONF_NAME>.service

Where CONF_NAME is the name of your .conf file in /etc/openvpn directory. In your case:

systemctl start openvpn@server.service

3. Enable service autostart if everything works

systemctl enable openvpn@server.service

After searching all over I found this link:

https://a20.net/bert/2016/09/27/openvpn-client-connection-not-started-on-ubuntu-16-04/

edit /etc/default/openvpn, uncomment AUTOSTART=”all”
sudo systemctl daemon-reload
sudo service openvpn restart

I boiled it down a bit more into :

echo 'echo "AUTOSTART=""all""" >> /etc/default/openvpn' | sudo -s
sudo systemctl daemon-reload
sudo service openvpn restart

Due to a bug in /etc/init.d/openvpn ?

# check if automatic startup is disabled by AUTOSTART=none
if test "x$AUTOSTART" = "xnone" -o -z "$AUTOSTART" ; then
 log_warning_msg " Autostart disabled."
 exit 0
fi
if test -z "$AUTOSTART" -o "x$AUTOSTART" = "xall" ; then
 # all VPNs shall be started automatically
 ...

It seems that if AUTOSTART is empty in /etc/default/openvpn then the scripts just exits.
So either you choose Phillip's solution or you remove in line 119 the second condition:

-o -z "$AUTOSTART"

As an alternative to Phillip Moxley’s answer,
you can edit the /etc/default/openvpn file
and change the AUTOSTART line to

AUTOSTART="server"