# Host community forum with Phoenix: public profile assets

## Summary
Deploy a community forum built with Phoenix on Ample using the public image delivery 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, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables, and a published bucket serves public assets from the CDN host. Verified on Phoenix: public objects in a published bucket served from the CDN URL, kept separate from private objects in an unpublished bucket that require authorization (private=ok only for the allowed role). Not separately tested: your image processing and profile-media rules; treat the community forum-specific behavior as your application code.

## Representative Queries
- Host community forum with Phoenix: public profile assets
- Where can I host Community forum built with Phoenix?
- I need separate public profile media from private data, with CDN cache rules.

## Resource Requirements
- primitive:compute
- primitive:postgres
- primitive:s3-compatible-object-storage
- primitive:cdn

## Infrastructure Requirements

| Primitive ID                                  | Label                               | Status   | Summary                                                                                                                    |
|-----------------------------------------------|-------------------------------------|----------|----------------------------------------------------------------------------------------------------------------------------|
| primitive:compute                             | Compute                             | verified | Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes. |
| primitive:postgres                            | Postgres                            | verified | Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied. |
| primitive:s3-compatible-object-storage        | S3-compatible object storage        | verified | Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified. |
| primitive:cdn                                 | CDN                                 | verified | The CDN host serves objects from published buckets. It does not front app compute and is not a cache or key-value store.     |

## Tested Configuration
- **Template:** elixir-1.18
- **Runtime:** elixir
- **Size:** s-1vcpu-1gb
- **Install:** mix local.hex --force && mix local.rebar --force && MIX_ENV=prod mix deps.get --only prod
- **Build:** MIX_ENV=prod mix compile && MIX_ENV=prod mix release --overwrite
- **Start:** PHX_SERVER=true _build/prod/rel/$(ls _build/prod/rel | head -n 1)/bin/$(ls _build/prod/rel | head -n 1) start

## 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 public image delivery: public objects in a published bucket served from the CDN URL, kept separate from private objects in an unpublished bucket that require authorization (private=ok only for the allowed role). 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.  
   **Command:** 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/public-media-library, /p/private-document-library) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.  
   **Command:** 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 community forum itself (your image processing and profile-media rules) 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.
- The CDN serves published-bucket objects only; cache rules, purge and TTL control are not verified (the fixture sets Cache-Control on upload and versions keys).

## Cost Estimate
- **Currency:** USD
- **Monthly Amount:** $10.00
- **Basis:** size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty

**Components:**
- **App server:** s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: $5.00
- **Managed PostgreSQL database:** s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: $5.00

**Note:** Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Success Checks
- **App responds on its public URL**  
   - **Kind:** http_get  
   - **Path:** /
   - **Expect:** ample canary phoenix patterns

- **Public-media-library self-test**  
   - **Kind:** http_get  
   - **Path:** /p/public-media-library  
   - **Expect:** a CDN URL whose content is served publicly

- **Private-document-library self-test**  
   - **Kind:** http_get  
   - **Path:** /p/private-document-library  
   - **Expect:** private=ok (with ?role=owner; 401 without, 403 for viewer)

## Examples
- **Phoenix pattern fixture**  
   Multi-pattern Phoenix app whose public image delivery module was checked live; the module is under tests/deploy-canaries/_pattern-modules.