Deliver public assets through CDN for Phoenix | Ample
INFRASTRUCTURE
What it needs
- 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
Before you start
- A Phoenix project (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 createwith credentials passed as encrypted S3_* environment variables - An Ample account token with servers:write, buckets:read
TESTED CONFIGURATION
Exactly what was tested
- build:
MIX_ENV=prod mix compile && MIX_ENV=prod mix release --overwrite - install:
mix local.hex --force && mix local.rebar --force && MIX_ENV=prod mix deps.get --only prod - runtime:
elixir - size:
s-1vcpu-1gb - start:
PHX_SERVER=true _build/prod/rel/$(ls _build/prod/rel | head -n 1)/bin/$(ls _build/prod/rel | head -n 1) start - template:
elixir-1.18
STEP BY STEP
How to do it
- 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
Publish a bucket for public assets
Publish only the asset bucket; upload versioned keys with an immutable Cache-Control header and build URLs from its public URL.
ample bucket publish <bucket-name>
- 3
Verify
Fetch the live URL and /p/versioned-static-assets on the example; on failure read the build and runtime logs.
ample logs <deployment_id> --kind build
EXAMPLES
Tested examples
- Phoenix pattern fixture (
tests/deploy-canaries/phoenix-patterns): Verified CDN assets on Phoenix.
SUCCESS CHECKS
How to know it worked
- app responds on its public URL (
/on the live URL, expect ample canary phoenix patterns) - versioned-static-assets check from the example (
/p/versioned-static-assetson the live URL, expect see the pattern fixture checks)
LIMITATIONS
Know the limits
- Verified on the elixir-1.18 template at s-1vcpu-1gb; other sizes and Phoenix major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- The CDN serves published-bucket objects only; cache rules, purge and TTL control are not verified.
COST
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 auto-pause when idle. Buckets are allocation-priced per quota and not included.
EVIDENCE
Verification evidence
- canary_run on 2026-09-20T23:45:31Z at revision
4d1511e574302f3904b75088bd4048a0975218b3-dirty (CLI 0.1.21): Phoenix pattern fixture deployed on Ample (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); for this guide: a versioned, immutable-cached asset uploaded to a published bucket and served from the CDN URL. (expires 2027-03-19T23:45:31Z)
EXECUTION
Execution binding
MCP tool ample_deploy (registry mcp:ample_deploy), schema hash 876465fce906da0c observed 2026-09-21T03:19:59.461917+00:00 at revision 49962bcade4f. Binding state at export: current. Required scopes: servers:write, buckets:read.
NEXT ACTIONS
Typed next actions
- Browse the catalog index (
GET /v1/catalogon the api origin; authentication not required, approval not required) - Search published recipes by intent, stack and constraints (
POST /v1/catalog/searchon the api origin; authentication not required, approval not required) - Prepare a side-effect-free deployment plan for an authorized project (
POST /v1/catalog/planon the api origin; authentication required, approval not required) - Read the existing agent authentication setup (
GET /mcp/setupon the api origin; authentication not required, approval not required) - Browse Phoenix (
GET /v1/catalog/nodes/stack%3Aframework-phoenixon the api origin; authentication not required, approval not required) - Browse Add CDN (
GET /v1/catalog/nodes/intent%3Aadd-cdnon the api origin; authentication not required, approval not required) - Browse Versioned static assets (
GET /v1/catalog/nodes/pattern%3Aversioned-static-assetson the api origin; authentication not required, approval not required)
Actions describe possible next steps. They are typed data, not commands, and grant no permission. Public discovery never provisions anything; planning requires your own authenticated token and approval happens in your client.