edp-doc/docs/technical-documentation/architecture/decisions/environment-hierarchy.md

# proposal: how to (re)structure our infrastructure setup

what we have:
* different providers - currently OTC and kind
* different groups of environments - currently called 'environment_namespace'
* different environments in each group of environments
* environments are called 'cluster_environment' and are terragrunt stacks, i.e. a huge set of resources where the kubernetes cluster itself is only one of them
* the top domain name (like t09.de, buildth.ing) is bound to the environment group

issues:
* in provider OTC there are two attributes for the environment group - 'tenant' and 'environment_namespace' are the same 
* missing hierarchy for other providers than otc - we directly start with 'prod' and 'non-prod' right now

## opportunity

right now we start switching to go code.
we can use this port to also restructure, generalize and improve the infrastructure and platfrom-provisioning.


## proposed environment hierarchy

* new: the 'environment_namespace' layer is called 'platformzone': "A neutral, abstract term that encompasses both the isolation (account, tenant, subscription) and the operational context (prod vs. non-prod)." (ChatGPT)
* new: folder 'environments'
* new: level 1 hierarchy 'provider'
* old: level 2 hierarchy 'platformzone'
* old: level 3 hierarchy 'environment'

### visualization

```bash
environments
├── provider:kind
│   └── platformzone:non-prod e.g.vm-1 or local
│       ├── edp
│       └── observability
├── provider:otc
│   ├── platformzone:non-prod i.e. tenant-1
│   │   ├── central-forgejo-aka-edp
│   │   ├── forgejo-dev
│   │   └── observability
│   └── platformzone:prod i.e. tenant-2
│       ├── edp
│       └── observability
└── provider:scaleway
    ├── platformzone:non-prod e.g. account-1
    └── platformzone:prod e.g. account-2
        ├── edp
        └── observability
```

![alt text](environments.png)