[knz]

At my work we use HAProxy, gunicorn/Flask (web apps and APIs) and a PostgreSQL container for development - we aren't planning to migrate the production databases to Docker anytime soon). We are using CoreOS for the host servers, dumping logs to logstash, and connect the containers via HAProxy. The big advantages we have seen are that it's easier to ensure consistency between development/qa/production, our deployment process is cleaner (basically docker pull container:latest, docker rm old-container, and docker create container:latest), and it's easier to resolve the few issues we have had (usually just a deploy vs tinkering on a live server). Our attitude has been to only use Docker for the parts of our stack that make sense (web apps and not production databases). It's been 8 months since we migrated and we haven't had any trouble yet.