It is currently no possible (or very difficult) to run Cloudflare WARP in docker as the warp-svc relies on systemd.
Our use-case is to be able to access resources running in cloudflared private networks from Kubernetes. Having an official WARP docker would allow this and make things a lot easier. The current solution, which I have not personally tried yet seems to be using the official wireguard client and some hacked together / unofficial cloudflare configuration.