OpenVPN

Server

Setup OpenVPN using docker

To quickly get a OpenVPN server up and running, the easiest solution would be to use docker and docker-compose and the image kylemanna/docker-openvpn. The following instructions are outlined in the project's documentation.

Create the following docker-compose file:

version: '2'
services:
  openvpn:
    cap_add:
     - NET_ADMIN
    image: kylemanna/openvpn
    container_name: openvpn
    ports:
     - "1194:1194/udp"
    restart: always
    volumes:
     - ./openvpn-data/conf:/etc/openvpn

Setup the config and PKI keys:

## Setup the config and PKI keys:
# docker-compose run --rm openvpn ovpn_genconfig -u udp://VPN.SERVERNAME.COM
# docker-compose run --rm openvpn ovpn_initpki

## Edit the OpenVPN configuration if desired.
# vi openvpn-data/conf/openvpn.conf

## Bring up the server
# docker-compose up -d openvpn

Create clients by generating a new client certificate and the client configuration file:

## with a passphrase (recommended)
# docker-compose run --rm openvpn easyrsa build-client-full $CLIENTNAME
## -or- without a passphrase (not recommended)
# docker-compose run --rm openvpn easyrsa build-client-full $CLIENTNAME nopass

## Generate the client config
# docker-compose run --rm openvpn ovpn_getclient $CLIENTNAME > $CLIENTNAME.ovpn

Configuration

The OpenVPN configuration is typically at /etc/openvpn/openvpn.conf.

Description	Option
Disable ping-restart. Defaults to keepalive 10 30, which corresponds to 10 second ping intervals and 30 second ping-restart.	keepalive 0 0
Allow multiple clients to connect	duplicate-cn
Add additional subnets to route through the VPN. The client will add a route for this particular subnet via the VPN gateway.	push "route 192.168.248.0 255.255.255.0"
Use TCP or UDP protocol. It's one or the other. You can't do both at the same time.	proto tcp or proto udp

Client

Usage

To connect to a VPN, run:

# openvpn --config config.ovpn

You will be prompted for a username and password if required.

See Also

• OpenVPN 2.4 reference manual - https://openvpn.net/community-resources/reference-manual-for-openvpn-2-4/