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on Phoenix: public objects in a published bucket served from the CDN URL, kept separate from private objects in an unpublished bucket that require authorization (private=ok only for the allowed role).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

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image delivery: public objects in a published bucket served from the CDN URL, kept separate from private objects in an unpublished bucket that require authorization (private=ok only for the allowed role).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 Keep private data in an unpublished bucket.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.