[jbmsf]

When I set up a product deployment system, I want:

1. IaC for the network, database, container definitions, and other cloud things. I use terraform here. 2. CI/CD for the application software, which ultimately builds a container image from version control, tags it in some well-know way, and tells the container scheduler to redeploy. I tend to use CircleCI, but any CI solution will do. 3. Configuration management for my container definitions, injecting environment variables for config/secrets into the definition or runtime. I tend to use Ansible or Terraform here.

For me, the main criteria is whether the product has a large number of components with configuration that needs to reuse common structures. If I'm just deploying one or two components (e.g. your typical early-stage monolith), Terraform is fine. Bt if you have many users contributing to many components and want to provide higher-level tools, I vastly prefer using Ansible; you just have more control.

That is, I believe in Ansible as a tool for applying configuration from source control to some other system; I would no longer use it to provision cloud resources.

[igetspam]

I've used ansible for parts of IaC. It was terrible. The person who made that decision had one tool in his box and it was ansible. I use it as part of packer, if I need complex changes while generating AMIs and I use it for my field deployed metal. It's great for both of those use cases.