> How do you propose terraform is supposed to discern between existing resources that belong to you and the ones that belong to another colleague/project?
All of them "belong to you" if you have IAM access to the resource. It's trivial to restrict access to resources in AWS if you shouldn't be touching something. The fact that so many orgs don't use IAM properly is not a reason to make a tool unnecessarily difficult to use.
So the question isn't if it "belongs to you", the question is whether you as the user want to do something with that particular resource that you already have permissions to modify. This could be accomplished at least a half dozen ways:
1. Is there a record in the state file of Terraform creating it? No? Then it's somebody else's resource
2. Ask the user
3. Command-line options
4. The code / DSL
5. Tags
6. Naming convention
But it does none of these things. It just craps out with a generic error and you're left to manually fuck around with the state halfway through it already started applying changes in production.
> 1. Declarative approach to the resource management
So it's declarative. Who cares? In the real world, there are resources that Terraform didn't create that you still have to deal with. There are also resources that Terraform did create, but you lost the state file, or you moved some modules, or changed the Terraform version by mistake and can't reverse your state file version, or a million other things. "Declarative" is not some magical word that means "the real world no longer applies".
> 2. Dependency graph management – dependency management is hard.
It's not that hard. If you already have a DAG and algorithms that can manipulate objects in it, there's only like 2 or 3 more functions you need to manipulate dependencies in a graph. This is really basic CS stuff. Dependency tracking is the same thing.
> What do you mean by overwriting existing resources?
I mean if there's an AWS record that Terraform wants to create and you didn't import it, Terraform fails. This is stupid, because 1) it's not even checking if the resource already exists (it has the data providers to do this), and 2) it's making me do something manually that it could do by itself with a flag or a config or DSL entry or a prompt.
The UX is fucking ridiculous. It's like whoever wrote Terraform has never actually used it, or just doesn't give a shit about blowing up production, or getting anything done in a reasonable amount of time. Classic "humans exist to serve machines", "opinionated" tech hipster bullshit. Must be the same person who did Git's UX. And impossibly, people defend it, as if technology is supposed to make our lives harder.