Composability is Critical in DevOps: let’s break the monoliths

This post was inspired by my Git for DevOps post and is an evolution of my “Functional Ops (the cake is a lie)” talks.

git_logo2016 is the year we break down the monoliths.  We’ve spent a lot of time talking about monolithic applications and microservices; however, there’s an equally deep challenge in ops automation.

Anti-monolith composability means making our automation into function blocks that can be chained together by orchestration.

What is going wrong?  We’re building fragile tightly coupled automation.

Most of the automation scripts that I’ve worked with become very long interconnected sequences well beyond the actual application that they are trying to install.  For example, Kubernetes needs etcd as a datastore.  The current model is to include the etcd install in the install script.  The same is true for SDN install/configuation and post-install test and dashboard UIs.  The simple “install Kubernetes” quickly explodes into a kitchen sink of related adjacent components.

Those installs quickly become fragile and bloated.  Even worse, they have hidden dependencies.  What happens when etcd changes.  Now, we’ve got to track down all the references to it burried in etcd based applications.  Further, we don’t get the benefits of etcd deployment improvements like secure or scale configuration.

What can we do about it?  Resist the urge to create vertical silos.

It’s temping and fast to create automation that works in a very prescriptive way for a single platform, operating system and tool chain.  The work of creating abstractions between configuration steps seems like a lot of overhead.  Even if you create those boundaries or reuse upstream automation, you’re likely to be vulnerable to changes within that component.  All these concerns drive operators to walk away from working collaboratively with each other and with developers.

Giving up on collaborative Ops hurts us all and makes it impossible to engineer excellent operational tools.  

Don’t give up!  Like git for development, we can do this together.