Dockerfile

@@ -1,7 +1,9 @@
-FROM alpine:3.9
+FROM alpine:3.12
 
-RUN apk add --no-cache openvpn
+ARG OPENVPN_PACKAGE_VERSION=2.4.9-r0
+RUN apk add --no-cache openvpn=$OPENVPN_PACKAGE_VERSION
 
 VOLUME /vpn-config
+ENV OPENVPN_CONFIG_PATH=/vpn-config/hackthebox.ovpn
 COPY ./vpn.sh /vpn.sh
 CMD ["/vpn.sh"]

docker-compose.yml

@@ -8,6 +8,8 @@ services:
     build: .
     image: fphammerle/hackthebox-gateway
     container_name: hackthebox_gateway
+    #environment:
+    #  OPENVPN_CONFIG_PATH: /vpn-config/config.ovpn
     volumes:
     - vpn_config:/vpn-config:ro
     devices:

vpn.sh

@@ -1,11 +1,11 @@
 #!/bin/sh
 
-set -ex
+set -eux
 
 iptables -P FORWARD DROP
 iptables -A FORWARD -i eth0 -o tun0 -d 10.10.10.0/24 -j ACCEPT
 iptables -A FORWARD -i tun0 -o eth0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
 iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
 
-openvpn --config /vpn-config/hackthebox.ovpn \
+openvpn --config "$OPENVPN_CONFIG_PATH" \
     --user openvpn --group openvpn