[cies]

> Having used Chef, Puppet, and Ansible

The only comparable system that I believe is a match for Ansible is SaltStack.

> As a functional programmer, I understand the benefits and appeal of declarative syntax. Unfortunately, systems programming is the one place where it's really hard to be 100% declarative, because systems are inherently all about state[0].

Have you looked into Nix/NixOS/NixOps? I think they have a really good approach to "functional configuration mgmt".

> perhaps things will change as we move toward better containerization models

I agree. When using scrappable VMs/containers (deploy to a new one, then scrap the old one) that are build from a description, it is in some ways quite close to approach in the Nix-camp.