Containers are all the rage these days, and for good reason: technologies such as Docker and CoreOS drastically simplify the packaging and shipping of applications, enabling them to scale without additional hardware or virtual machines. But with these benefits come issues related to management overhead and complexity—namely, how can developers quickly achieve visibility and validate configurations across distributed container clusters? The answer is with UpGuard's new etcd monitoring capabilities.
One of the easiest ways to build applications programmatically into containers through Docker is to use a Dockerfile. Dockerfiles are the Makefiles of the Docker world. A ton of blog posts and tutorials have sprung up over the last few months about how to set up Docker, or how to set up a LAMP stack and even a LEMP stack in Docker.
Tonight I gave a talk on comparing containers and generating Dockerfiles. Instead of providing the slides, which are pretty lame by themselves, I thought I'd write up the talk in a proper context. UpGuard has a number of use cases, one of which highlighted for the talk was migrating the configuration of environments from one location to another. Traditionally we have helped some of our customers scan their configuration state and generate executable tests based on those configuration items as well as allow scanned configuration from multiple machines to be compared.