OpenConnect VPN Server

OpenConnect VPN server is an SSL VPN server that is secure, small, fast and configurable. It implements the OpenConnect SSL VPN protocol and has also (currently experimental) compatibility with clients using the AnyConnect SSL VPN protocol. The OpenConnect protocol provides a dual TCP/UDP VPN channel and uses the standard IETF security protocols to secure it. The OpenConnect client is multi-platform and available here. Alternatively, you can try connecting using the official Cisco AnyConnect client (Confirmed working on Android).

The dockerfile was written to always download and compile the latest release of OpenConnect VPN server when built.*

* OpenConnect dev team has taken to listing unreleased versions on the page I pull with curl to get the current version so I had to modify the command to pull the second most recent version instead. Since I dont control this page it is subject to change back at anytime, keep that in mind if you fork this container.

Homepage

Documentation

Source

Docker Features

• Base: Alpine 3.13
• Latest OpenConnect Server 1.1.2
• Size: 63.6MB
• Modification of the listening port for more networking versatility
• Customizing the DNS servers used for queries over the VPN
• Supports tunneling all traffic over the VPN or tunneling only specific routes via split-include
• Config directory can be mounted to a host directory for persistence
• Create certs automatically using default or provided values, or drop your own certs in /config/certs
• Advanced manual configuration for power users

Run container from Docker registry

The container is available from the Docker registry and this is the simplest way to get it.

Basic Configuration

Without customizing cert variables

$ docker run --privileged  -d \
              -p 4443:4443 \
              -p 4443:4443/udp \
              markusmcnugen/openconnect

With customizing cert variables

$ docker run --privileged  -d \
              -p 4443:4443 \
              -p 4443:4443/udp \
              -e "CA_CN=VPN CA" \
              -e "CA_ORG=OCSERV" \
              -e "CA_DAYS=9999" \
              -e "SRV_CN=vpn.example.com" \
              -e "SRV_ORG=MyCompany" \
              -e "SRV_DAYS=9999" \
              markusmcnugen/openconnect

Intermediate Configuration (Providing own certs in /config/certs and running on port 443):

Cert files are stored in /config/certs. It will automatically generate certs if the following two files are not present in the cert directory:

server-key.pem
server-cert.pem

$ docker run --privileged  -d \
              -v /your/config/path/:/config \
              -e "LISTEN_PORT=443" \
              -e "DNS_SERVERS=192.168.1.190" \
              -e "TUNNEL_MODE=split-include" \
              -e "TUNNEL_ROUTES=192.168.1.0/24" \
              -e "SPLIT_DNS_DOMAINS=example.com" \
              -p 443:443 \
              -p 443:443/udp \
              markusmcnugen/openconnect

Advanced Configuration:

This container allows for advanced configurations for power users who know what they are doing by mounting the /config volume to a host directory. Users can then drop in their own certs and modify the configuration. The POWER_USER environmental variable is required to stop the container from overwriting options set from container environment variables. Some advanced features include setting up site to site VPN links, User Groups, Proxy Protocol support and more.

Variables

Environment Variables

Variable	Required	Function	Example
LISTEN_PORT	No	Listening port for VPN connections	LISTEN_PORT=4443
DNS_SERVERS	No	Comma delimited name servers	DNS_SERVERS=8.8.8.8,8.8.4.4
TUNNEL_MODE	No	Tunnel mode (all / split-include)	TUNNEL_MODE=split-include
TUNNEL_ROUTES	No	Comma delimited tunnel routes in CIDR notation	TUNNEL_ROUTES=192.168.1.0/24
SPLIT_DNS_DOMAINS	No	Comma delimited dns domains	SPLIT_DNS_DOMAINS=example.com
POWER_USER	No	Allows for advanced manual configuration via host mounted /config volume	POWER_USER=no

Volumes

Volume	Required	Function	Example
config	No	OpenConnect config files	/your/config/path/:/config

Ports

Port	Proto	Required	Function	Example
4443	TCP	Yes	OpenConnect server TCP listening port	4443:4443
4443	UDP	Yes	OpenConnect server UDP listening port	4443:4443/udp

How to use this OpenConnect Server Docker

Install and run the docker container with your chosen options. Port forward incoming traffic on your router, some outside port to the containers IP and the listening port on the inside. After port forwarding is established you will need to create VPN accounts for users to login with usernames and passwords.

Example:

Incoming Outside Port 4443 Forwarding TCP and UDP to the OpenConnect Servers inside IP address and listening port

Add User/Change Password

Add users by executing the following command on the host running the docker container

docker exec -ti openconnect ocpasswd -c /config/ocpasswd markusmcnugen
Enter password:
Re-enter password:

Delete User

Delete users by executing the following command on the host running the docker container

docker exec -ti openconnect ocpasswd -c /config/ocpasswd -d markusmcnugen

Login and Logout Log Messages

After a user successfully logins to the VPN a message will be logged in the docker log.
Example of login message:

[info] User markusmcnugen Connected - Server: 192.168.1.165 VPN IP: 192.168.255.194 Remote IP: 107.92.120.188 

Example of logoff message:

[info] User markusmcnugen Disconnected - Bytes In: 175856 Bytes Out: 4746819 Duration:63

Building the container yourself

To build this container, clone the repository and cd into it.

Build it:

$ cd /repo/location/openconnect
$ docker build -t openconnect .

Run it:

$ docker run --privileged  -d \
              -p 4443:4443 \
              -p 4443:4443/udp \
              openconnect

This will start a container as described in the "Run container from Docker registry" section. View the other run configurations for more advanced setups.