P2-1 Summary

---
category: reference
tags:
  - P2
  - dynamodb
  - infrastructure
last_updated: 2026-03-13
---

# P2-1: DynamoDB Tables — Summary

## Status: Complete

## Acceptance Criteria

- [x] Users table: create, read, update by ID; lookup by (oauth_provider, oauth_provider_sub)
- [x] Wikis table: create, read, update, delete by (owner_id, wiki_slug); list by owner
- [x] ACLs table: create, read, delete by (wiki_id, grantee_id); list by wiki
- [x] PITR enabled on all tables
- [x] Unit tests pass with moto (22/22)
- [ ] Integration test: CRUD against real DynamoDB (not run — `pulumi up` deferred per task spec)

## Files Changed

- `infra/components/dynamodb.py` — Pulumi `DynamoDbComponent` with 3 tables + GSI
- `infra/__main__.py` — import + instantiation appended at end (no conflicts with P1-5/P1-6)
- `app/models/__init__.py` — package init, re-exports all models
- `app/models/user.py` — `UserModel` (create, get, get_by_oauth, update)
- `app/models/wiki.py` — `WikiModel` (create, get, update, delete, list_by_owner)
- `app/models/acl.py` — `AclModel` (create, get, delete, list_by_wiki)
- `tests/test_dynamodb.py` — 22 unit tests with moto

## Design Decisions

1. **Table keys follow the data model exactly.** Users PK=id, Wikis PK=owner_id+SK=wiki_slug, ACLs PK=wiki_id+SK=grantee_id.
2. **Single GSI on Users** for `(oauth_provider, oauth_provider_sub)` login lookup. No GSI needed on Wikis (listing by owner is a native PK query) or ACLs (listing by wiki is a native PK query).
3. **ACL wiki_id is a composite string** (`owner_id:wiki_slug`), matching the data model comment "owner_id + wiki_slug".
4. **ACL create is an upsert** — re-granting a role overwrites the previous entry (no conditional write). This is intentional for role changes.
5. **Wiki and User creates use conditional writes** to prevent duplicates.
6. **PAY_PER_REQUEST billing** for dev (no capacity planning needed).
7. **All resources tagged** with `project: wikibot-io`, `environment: dev`.
8. **Plain boto3, no ORM** — models accept a `dynamodb_resource` parameter for dependency injection (used by moto in tests).

## Test Results

```
22 passed in 15.19s
```

All CRUD operations, GSI queries, conditional writes, error cases, and upsert behavior verified.

## Pulumi Preview

Preview shows 3 new DynamoDB tables + 1 component resource, no conflicts with existing infrastructure.

## Branch

`feat/P2-1-dynamodb` — 1 commit, not pushed.