openvpn-install | OpenVPN server on Debian , Ubuntu , Fedora , CentOS or Arch | VPN library

It's also possible to run the script headless, e.g. without waiting for user input, in an automated manner. A default set of variables will then be set, by passing the need for user input. If you want to customise your installation, you can export them or specify them on the same line, as shown above. If the server is behind NAT, you can specify its endpoint with the ENDPOINT variable. If the endpoint is the public IP address which it is behind, you can use ENDPOINT=$(curl -4 ifconfig.co) (the script will default to this). The endpoint can be an IPv4 or a domain. Other variables can be set depending on your choice (encryption, compression). You can search for them in the installQuestions() function of the script. Password-protected clients are not supported by the headless installation method since user input is expected by Easy-RSA. The headless install is more-or-less idempotent, in that it has been made safe to run multiple times with the same parameters, e.g. by a state provisioner like Ansible/Terraform/Salt/Chef/Puppet. It will only install and regenerate the Easy-RSA PKI if it doesn't already exist, and it will only install OpenVPN and other upstream dependencies if OpenVPN isn't already installed. It will recreate all local config and re-generate the client file on each headless run.
APPROVE_INSTALL=y
APPROVE_IP=y
IPV6_SUPPORT=n
PORT_CHOICE=1
PROTOCOL_CHOICE=1
DNS=1
COMPRESSION_ENABLED=n
CUSTOMIZE_ENC=n
CLIENT=clientname
PASS=1