# Host knowledge base with Phoenix: Postgres-backed content

## Summary
Deploy a knowledge base built with Phoenix on Ample using the relational records pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL, and a published bucket serves public assets from the CDN host. Verified on Phoenix: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). Not separately tested: your record schema, states and access rules; treat the knowledge base-specific behavior as your application code.

## Representative Queries
- Host knowledge base with Phoenix: Postgres-backed content
- Where can I host Knowledge base built with Phoenix?
- I need a content schema, publishing workflow and cache behavior after content updates.

## Resource Requirements
- `primitive:compute`
- `primitive:postgres`
- `primitive:cdn`

## Workflow Steps
1. **Build and start**  
   mix deps.get, MIX_ENV=prod mix compile and mix release in the builder, then the release bin script with PHX_SERVER=true on the elixir-1.18 template; PORT, DATABASE_URL and SECRET_KEY_BASE read in config/runtime.exs. The server must bind 0.0.0.0 on PORT.

2. **Implement the pattern on PostgreSQL**  
   The fixture's module implements relational records: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. **Wire object storage**  
   Create the bucket(s), then pass endpoint, region, bucket and keys as --env values. Use path-style addressing. Keep private data in an unpublished bucket. Publish only the bucket that serves public assets and reference its CDN URL.

4. **Deploy**  
   Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.  
   `ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=... --env CDN_PUBLIC_URL=...`

5. **Verify**  
   Fetch the live URL and the pattern self-test route(s) (/p/relational-records) from the example; then run your own checks. On failure read `ample logs --kind build` then `--kind runtime`.  
   `ample logs --kind build`

## Limitations
- Verified on the elixir-1.18 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Phoenix major versions are not verified.
- The knowledge base itself is application code and was not separately tested; the pattern checks are what was verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.
- PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not verified.
- The CDN serves published-bucket objects only; cache rules, purge and TTL control are not verified.

## Cost Estimate
- **Currency**: USD  
- **Monthly Amount**: 10.0  
- **Components**:  
  - App server  
    - Size: s-1vcpu-1gb  
    - Quantity: 1.0  
    - Monthly Amount: 5.0  
  - Managed PostgreSQL database  
    - Size: s-1vcpu-1gb  
    - Quantity: 1.0  
    - Monthly Amount: 5.0  
- **Note**: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

## Next Actions
- **Browse the catalog index**  
  - Method: `GET`  
  - Path: `/v1/catalog`

- **Search published recipes by intent, stack and constraints**  
  - Method: `POST`  
  - Path: `/v1/catalog/search`  
  - Body: `{ "limit": 5, "query": "Host knowledge base with Phoenix: Postgres-backed content" }`

- **Prepare a side-effect-free deployment plan for an authorized project**  
  - Method: `POST`  
  - Path: `/v1/catalog/plan`  
  - Body: `{ "inputs": {}, "projectId": "", "recipeId": "page:recipes:knowledge-base:phoenix:relational-content", "recipeRevision": "r1" }`

- **Browse Knowledge base**  
  - Method: `GET`  
  - Path: `/v1/catalog/nodes/workload%3Aknowledge-base`

- **Browse Phoenix**  
  - Method: `GET`  
  - Path: `/v1/catalog/nodes/stack%3Aframework-phoenix`

- **Browse Relational records**  
  - Method: `GET`  
  - Path: `/v1/catalog/nodes/pattern%3Arelational-records`

- **Browse Deploy web app**  
  - Method: `GET`  
  - Path: `/v1/catalog/nodes/intent%3Adeploy-web-app`