feat(datastore/postgres): logical flavour

[anshulsao]

What

Adds a new logical flavour for datastore/postgres at modules/datastore/postgres/logical/1.0.

This flavour models a logical database hosted on an existing/shared PostgreSQL instance. It creates no cloud resources and declares no providers: it references an existing postgres instance and re-exposes that instance's connection outputs under the same @facets/postgres contract that aws-rds and aws-aurora emit (so consumers can't tell a logical DB from a dedicated instance).

Named logical (not reference) to avoid clashing with Facets' cross-blueprint reference concept; "logical" describes the actual use case — a logical database co-located on a shared physical instance.

How it works

• spec.source — a spec field with x-ui-output-type: '@facets/postgres'. This resolves to the selected resource's full outputs (interfaces + attributes) injected into var.instance.spec.source. Because it's a spec field, the target is per-environment override-able — the same blueprint resource can point at different shared instances across environments (e.g. via a --flavor/override on stage).
• spec.database_name — optional, override-only. The logical DB name to target on the shared host. When set, the reader/writer connection_string is rebuilt as postgres://<source-user>:<source-pass>@<source-host>:<source-port>/<database_name> (credentials/host/port inherited from the source; only the database segment swapped). When unset, the source connection string passes through verbatim.
• main.tf declares no resources; outputs.tf re-emits output_interfaces.reader/writer (host, port, username, password, connection_string, secrets) and passes through output_attributes from the source.

Coverage

Because both aws-rds and aws-aurora emit @facets/postgres, this single logical flavour covers both as source instances.

Use case

Staging DB consolidation — a logical database that points at a shared physical instance. Deploy one real postgres instance, then one postgres/logical per service with source -> the shared instance and database_name -> the service's logical DB. Blueprints stay identical across environments while non-prod consolidates physical infra.

Validation

• terraform fmt / init -backend=false / validate — clean.
• raptor create iac-module -f modules/datastore/postgres/logical/1.0 --dry-run — all validations pass (facets.yaml, var.inputs, var.instance.spec, no provider blocks, terraform validate, output types). Trivy not installed locally so the security scan was skipped (no scan findings; nothing security-relevant — module provisions nothing).
• Catalog updated per the New Module Checklist: README.md, index.html, and all three project-type/{aws,gcp,azure}/project-type.yml (cloud-neutral flavour, added to all). Icon already exists (icons/postgres.svg).

🤖 Generated with Claude Code

https://claude.ai/code/session_01PKZUrLtUbJS5GuEyRA8Vd5