This solution allows you to access your Docker for Mac's internal networks directly from your macOS host machine, using OpenVPN.
To access your Docker networks:
docker-compose up. The first time it will take up to a minute to startup, because it needs to generate keys.docker-for-mac.ovpn in Finder (or run open docker-for-mac.ovpn in your terminal) to add it to Tunnelblick. You will find it in the current folder.You will now be able to access the internal Docker networks from macOS.
The Compose configuration consists of two services, both based on the tiny Alpine Linux distribution.
The OpenVPN image used is kylemanna/openvpn.
Both server-side and client-side configuration are automatically generated by helpers/run.sh, which calls the helper scripts in original image and adjust configuration for accessing the Docker for Mac networks only.
This service runs on TCP port 1194 using host networking, which means it has access to all Docker networks in the host VM.
Only the 172.16.0.0/20 private network is routed to Docker for Mac by the generated config. No DNS servers are set on the host.
The OpenVPN configuration (/etc/openvpn/*) is stored locally in ./config/ so that it survives Docker filesystem resets and allows for easy customization.
Since containers running in host networking mode in Docker for Mac cannot bind ports to make them accessible from macOS, we need an extra TCP proxy. This image uses socat to forward port 13194 to the OpenVPN container.
restart: always to both services in docker-compose.yml to have them automaticaly restart.route statements in your docker-for-mac.ovpnapp_net examples in the Compose file referenceconfig/* and docker-for-mac.ovpn