
Since version 1.12, Docker removed `docker.socket` <https://docs.docker.com/release-notes/docker-engine/> The problem was already present on RPM systems (e.g. RHEL, Fedora, CentOS), and now also seems to affect Debian 9 (Stretch). This change replaces `docker.socket` by `docker.service`. It solves this problem: ``` > systemctl start docker-openvpn@.service Failed to start docker-openvpn@.service: Unit docker.socket not found. ``` Related issues: - <https://github.com/kylemanna/docker-openvpn/issues/280> - <https://github.com/kylemanna/docker-openvpn/pull/286>