openconnect + microsocks

This Docker image contains an openconnect client (version 8.10 with pulse/juniper support) and the microsocks proxy for socks5 connections (default on port 8889) in a very small alpine linux image (around 20 MB).

You can find the image on docker hub: https://hub.docker.com/r/cbwang/openconnect-proxy

Requirements

If you don't want to set the environment variables on the command line set the environment variables in a .env file:

OPENCONNECT_URL=<Gateway URL>
OPENCONNECT_USER=<Username>
OPENCONNECT_PASSWORD=<Password>
OPENCONNECT_OPTIONS=--authgroup <VPN Group> \
	--servercert <VPN Server Certificate> --protocol=<Protocol> \
	--reconnect-timeout 86400

Don't use quotes around the values!

See the openconnect documentation for available options.

Either set the password in the .env file or leave the variable OPENCONNECT_PASSWORD unset, so you get prompted when starting up the container.

Optionally set a multi factor authentication code:

OPENCONNECT_MFA_CODE=<Multi factor authentication code>

Run container in foreground

To start the container in foreground run:

docker run -it --rm --privileged --env-file=.env \
  -p 8889:8889 cbwang/openconnect-proxy:latest

The proxies are listening on ports 8889 (socks). Either use --net host or -p <local port>:8889 to make the proxy ports available on the host.

Without using a .env file set the environment variables on the command line with the docker run option -e:

docker run … -e OPENCONNECT_URL=vpn.gateway.com/example \
-e OPENCONNECT_OPTIONS='<Openconnect Options>' \
-e OPENCONNECT_USER=<Username> …

Run container in background

To start the container in daemon mode (background) set the -d option:

docker run -d -it --rm …

In daemon mode you can view the stderr log with docker logs:

docker logs `docker ps|grep "cbwang/openconnect-proxy"|awk -F' ' '{print $1}'`

Use container with docker-compose

vpn:
  container_name: openconnect_vpn
  image: cbwang/openconnect-proxy:latest
  privileged: true
  env_file:
    - .env
  ports:
    - 8889:8889
  cap_add:
    - NET_ADMIN
  networks:
    - mynetwork

Set the environment variables for openconnect in the .env file again (or specify another file) and map the configured ports in the container to your local ports if you want to access the VPN on the host too when running your containers. Otherwise only the docker containers in the same network have access to the proxy ports.

Route traffic through VPN container

Let's say you have a vpn container defined as above, then add network_mode option to your other containers:

depends_on:
  - vpn
network_mode: "service:vpn"

Keep in mind that networks, extra_hosts, etc. and network_mode are mutually exclusive!

Configure proxy

The container is connected via openconnect and now you can configure your browser and other software to use one of the proxies (8889 for socks).

ssh through the proxy

You need nc (netcat), corkscrew or something similar to make this work.

Unfortunately some git clients (e.g. Gitkraken) don't use the settings from ssh config and you can't pull/push from a repository that's reachable (DNS resolution) only through VPN.

nc (netcat, ncat)

Set a ProxyCommand in your ~/.ssh/config file like

Host <hostname>
	ProxyCommand            nc -x 127.0.0.1:8889 %h %p

or (depending on your ncat version)

Host <hostname>
	ProxyCommand            ncat --proxy 127.0.0.1:8889 --proxy-type socks5 %h %p

and your connection will be passed through the proxy. The above example is for using git with ssh keys.

Build

You can build the container yourself with

docker build -f build/Dockerfile -t cbwang/openconnect-proxy:custom ./build