# Host knowledge base with Phoenix: public-site delivery

## Summary

Deploy a knowledge base built with Phoenix on Ample using the public web service pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, and a published bucket serves public assets from the CDN host. Verified on Phoenix: a versioned, immutable-cached asset uploaded to a published bucket and served from the CDN URL alongside the app's own public HTTPS URL. Not separately tested: your site content and build; treat the knowledge base-specific behavior as your application code.

## Infrastructure requirements

- 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.)
- 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.)

## Prerequisites

- 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)
- A bucket from `ample bucket create` with its credentials passed as encrypted S3_* environment variables
- An Ample account token with servers:write, buckets:read

## Exact 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`

## 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. **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 Keep private data in an unpublished bucket.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.
3. **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 <app-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=...
   ```
4. **Verify.** Fetch the live URL and the pattern self-test route(s) (/p/versioned-static-assets) from the example; then run your own checks. On failure read `ample logs <deployment_id> --kind build` then `--kind runtime`.
   ```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **Phoenix pattern fixture** (tests/deploy-canaries/phoenix-patterns): Multi-pattern Phoenix app whose public web service module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

## Success checks

- app responds on its public URL (`/` on the live URL, expect ample canary phoenix patterns)
- versioned-static-assets self-test (`/p/versioned-static-assets` on the live URL, expect a CDN URL whose content is served publicly)

## 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 (your site content and build) 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.
- 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

Estimated 5.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371).
- app server x1 `s-1vcpu-1gb`: 5.00 USD

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