Update 29 September 2018: Since the release of AWS Step Functions, this pattern is out of date. Orchestrating deployment with a slim lambda function is still a solid pattern, but Step Functions could make the implementation simpler and could provide more features (like graphical display of deployment status). You can even see some of the ways this might work in AWS’s DevOps blog. Those implementation changes would drive some re-architecture, too. Because those are major changes, for now Pear is an interesting exploration of a pattern but isn’t ready for use in new deployments.
A while back I wanted to put a voice interface in front of my deployment automation. I think passwords on voice interfaces are annoying and aren’t secure, so I wanted an unauthenticated system. I didn’t want to lay awake at night worried about all the things people could break with it, so I set out to engineer a deployment infrastructure that I could put behind voice control and still feel was secure and reliable.
After a lot of learning (the journey towards this is where the Life Coach and the Better Alexa Quick Start came from) and several revisions, I had built my new infrastructure. For reasons I can’t remember, I called it Pear.
Pear is designed to make it easy to add slick features like voice interfaces while giving you enough control to stay secure and enough stability to operate in production. It’s meant for infrastructures too complex to fit in tools like Heroku or Elastic Beanstalk, for situations where you need to be able to turn all the knobs. I think it achieves those goals, so I decided to publish it. Check out the repo for an example implementation and more complete documentation of its features, but to give you a taste here’s a diagram of the basic architecture: