# Host approval workflow with Phoenix: CSV imports

Deploy a approval workflow built with Phoenix on Ample using the bulk import staging 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. Verified on Phoenix: a CSV staged as an object, row-level validation with per-row errors recorded, and a restart-safe import keyed by import id (imported=2 rejected=1 restart=ok). Not separately tested: your import format, mapping and conflict rules; treat the approval workflow-specific behavior as your application code.

## Representative Queries
- Host approval workflow with Phoenix: CSV imports
- Where can I host Approval workflow built with Phoenix?
- I need a domain CSV format, row validation, deduplication and an import recovery path.

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

## Infrastructure Requirements
- **Compute**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
- **Postgres**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
- **S3-compatible object storage**: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

## Prerequisites
1. A Phoenix project that builds and starts with the documented commands (`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`)
2. A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with `--env`)
3. A bucket from `ample bucket create` with its credentials passed as encrypted `S3_*` environment variables
4. An Ample account token with `servers:write`, `databases:read`, `buckets:read`

## 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 bulk import staging: a CSV staged as an object, row-level validation with per-row errors recorded, and a restart-safe import keyed by import id (imported=2 rejected=1 restart=ok). 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.
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.
   ```shell
   ample deploy . --name  --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...
   ```
5. **Verify**: Fetch the live URL and the pattern self-test route(s) (`/p/bulk-import-staging`) from the example; then run your own checks. On failure read `ample logs --kind build` then `--kind runtime`.
   ```shell
   ample logs --kind build
   ```

## Examples
### Phoenix pattern fixture
- **Description**: Multi-pattern Phoenix app whose bulk import staging module was checked live; the module is under `tests/deploy-canaries/_pattern-modules`.
- **Source Reference**: `tests/deploy-canaries/phoenix-patterns`

## Success Checks
- **App responds on its public URL**: HTTP GET on `/` should expect `ample canary phoenix patterns`
- **Bulk-import-staging self-test**: HTTP GET on `/p/bulk-import-staging` should expect `imported=2 rejected=1 restart=ok`

## 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 approval workflow 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.