For the hosts we manage, my boss has a vision of configuration management via versioned packages (in our particular case, fpm-built debian packages). This is to make:
- host deployment easier
- easier to track local changes
- make bug tracking easier as in most cases, we can tag a version of software to a bug, whether it is a functional or configuration bug.
The other alternative is configuration management via Ansible, with their recommended layout as in their manual, which we are using currently. We install versioned packages of software (pretty much all web services), which would be responsible for it's own package-specific configuration, and leave Ansible to system-wide configuration. Updating hosts software is simply a matter of bumping version numbers and rerunning the scripts. We rely heavily on the "var_prompts" functionality of Ansible to ensure we keep sensitive information separate from the configuration.
In the "configuration management via versioned packages" case:
For deployment, we just bring up a minimal server (proxies etc) and use a package manager (apt in our case) to install a single umbrella package, that would install all the dependent packages. Making a change to any of the dependent packages would simply bump up the top most package version, making it easier to update existing deployments.
For configuration, each software package would have an accompanying "config" package, to allow changes to configuration only. Each package would have independent configuration files, to prevent conflicts between packages when we verify local changes on the host. Instead of running commands that generate config, we would ensure that we would have the generated files as part of the package, but still allow running of commands via the pre/post install scripts. AFAIK, there aren't a great number of cases where we have packages that will rely on the same configration file, but if that is the case (which would be the case for system configuration), we would have another package that would have a dependency on both. I can see this particular case getting out of control, but this could be controlled by always ensuring independent config files. In the end, each host would have their own unique config package. Obviously, all these files would be under source control, and we may spin up our own simple templating system, so that we can also have the flexibility of Ansible roles.
I am curious why I cannot find any information/analysis on this type of workflow for configuring and deploying hosts. Am I missing something fundamentally flawed with such an approach, in comparison to existing configuration management tools?