virtusai/docker-firewall repository overview

Source Code (GitHub)⁠

Firewall rules for Docker published ports (based on confd-firewall⁠).

⁠Background

This image allows firewall rules to be managed by a docker container which blocks traffic to the public interface from non-whitelisted addresses. Iptable rules are added to the mangle table.

⁠Environment Variables

• FW_SERVICE - A prefix for the firewall table rules.
• FW_PROTO - Comma-separated list of protocols to expose (e.g. tcp or udp or tcp,udp)
• FW_PORTS - Comma-separated list of port numbers to expose (ranges allowed)
• FW_STATIC - Comma-separated list of IPs/CIDRs to always allow.
• FW_DISABLE - If set to 1, disables the firewall (removes the firewall table rules)

⁠Usage

Run with:

$ docker run -d --name docker-firewall --env FW_SERVICE=example --env FW_PROTO=tcp --env FW_PORTS=6379 --env FW_STATIC="8.9.10.11/30,18.19.20.21/30" --restart=always --cap-add=NET_ADMIN --net=host virtusai/docker-firewall

Or with docker-compose yml:

version: '2'
services:
  firewall:
    restart: always
    image: virtusai/docker-firewall
    container_name: docker-firewall
    environment:
      - FW_SERVICE=example
      - FW_PROTO=tcp
      - FW_PORTS=6379
      - FW_STATIC=8.9.10.11/30,18.19.20.21/30
    cap_add:
      - NET_ADMIN
    network_mode: host

List affected rules:

Raw

$ sudo iptables-save -t mangle

Formatted

$ sudo iptables -L -n -v -t mangle

To persist the firewall rules, just run the container with the --restart=always option.

⁠Credits

• confd-firewall⁠ (by colinmollenhour⁠)