docker build -t openconnect .
docker run --cap-add NET_ADMIN --device /dev/net/tun:/dev/net/tun \
-e OPENCONNECT_URL=example.com \
-e OPENCONNECT_AUTHGROUP=AGRP \
-e OPENCONNECT_USER=foobar@example.com \
-e OPENCONNECT_PASSWORD=Secr3t! \
-e SSH_PUBKEY="ssh-ed25519 ..." \
-d --name openconnect openconnect
ssh -J root@$(docker inspect -f '{{ .NetworkSettings.IPAddress }}' openconnect) user@host