We are running our app[1] in instances of Google Compute Engine. We installed Docker in those instances.
Our app is a bunch of microservices, some Rails Apps each one running with Puma as webserver, HAProxy, some other Rack app (for Websockets). We also use RabbitMQ and Redis.
All the components are running in their own containers (we have dozens of containers running to support this app).
We choose this path because in case of failures, just 1 service would be down meanwhile the whole system is nearly fully functional. Re-launching a container is very straightforward and is done quickly.
[1]: https://dockerize.it