Earlier, I wrote about zero downtime docker deployment with Tutum. I have recently started experimenting with Amazon ECS (EC2 Container Service), which is Amazon’s offering for the orchestration of Docker containers (and thus a competitor to Tutum). I don’t have a lot of experience with ECS yet, but it looks pretty solid so far. I found there was a real lack of documentation on how to deploy updated Docker images to Amazon, however, and was forced to do some research in order to figure out how it should be done.

In this post I will detail how to achieve (almost) zero downtime deployment of Docker containers with the Tutum Docker hosting service. Tutum is a service that really simplifies deploying with Docker, and it even has special facilities for enabling zero downtime deployment, i.e. the Tutum team has a version of HAProxy that can switch seamlessly between Docker containers in tandem with Tutum’s API. There is the caveat though, that at the time of writing, there is slight downtime involved with HAProxy’s switching of containers, typically a few seconds.

In my search for a comprehensive logging solution for MuzHack that works in a Dockerized environment, more specifically Tutum, I came across Papertrail. Papertrail is a fairly simple Web application for log aggregation, that receives log data over the Internet through the syslog protocol. As a registered user of Papertrail, you receive a syslog address that serves as your logging destination. Multiple sources (or "systems" as per Papertrail lingo) can use the same logging destination, as Papertrail will automatically discern between them (based on their hostnames).