How to route Docker container over a specific host interface?
By leaving line 25 commented we only routing traffic from the docker vpn network over the OpenVPN. The down.sh script removes the $trusted_ip which was added during setup. Finally, we want to avoid that packets go over over the eth0 interface if the OpenVPN on tun0 is down.
What happens if the interface goes down in Docker?
If the interface goes down then the docker container is not allowed to communicate through any other interface. First configure docker such that it does not get into our way in /etc/docker/daemon.json:
How to inspect network traffic in Docker containers?
Inspecting Docker container network traffic – Byteplumbing When developing dockerized services with other communication end-points than browser client one soon needs some ways to capture and debug network traffic from containers. Here’s some tools and tips I’ve been using. Byteplumbing Fiddling with code and stuffing bytes into pipes Archive
How can I bind Docker container to specific external?
Or if you always want Docker port forwards to bind to one specific IP address, you can edit your system-wide Docker server settings and add the option –ip=IP_ADDRESS. Remember to restart your Docker server after editing this setting. Thanks for contributing an answer to Stack Overflow!
How to add rules to forward chain in Docker?
IPtables rules are a bit of a pain with docker. Docker overwrites the iptables configuration when it starts. So if you want to add rules to the FORWARD chain you have to add the rules to DOCKER-USER instead such that they are not overwritten. You can read more about this in the manual. Basically we are acting here like a router.
Why do we use proxy in Docker container?
Most of the time a proxy within the Virtual Private Network is used to achieve this. This has also the benefit that, if the network interface does down and the routing rules are reset, then the traffic is not sent though some other default interface.